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Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2011	Apr. 15, 2011
Document and Entity Information
Entity Registrant Name	INTUITIVE SURGICAL INC
Entity Central Index Key	0001035267
Current Fiscal Year End Date	--12-31
Trading Symbol	ISRG
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		39,287,961
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q1

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 449.8	$ 279.8
Short-term investments	640.0	630.6
Accounts receivable, net	259.9	246.8
Inventory	93.3	86.8
Prepaid and other assets	32.2	23.3
Deferred tax assets	8.4	8.5
Total current assets	1,483.6	1,275.8
Property, plant and equipment, net	162.6	159.8
Long-term investments	667.2	698.5
Long-term deferred tax assets	65.5	73.3
Intangible and other assets, net	72.5	66.1
Goodwill	116.9	116.9
Total assets	2,568.3	2,390.4
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	43.2	35.6
Accrued compensation and employee benefits	43.4	63.4
Deferred revenue	130.3	126.1
Other accrued liabilities	35.4	48.7
Total current liabilities	252.3	273.8
Other long-term liabilities	85.1	79.2
Total liabilities	$ 337.4	$ 353.0
Commitments and contingencies
Stockholders' equity:
Preferred stock, 2.5 shares authorized, $0.001 par value, issuable in series; no shares issued and outstanding as of March 31, 2011 and December 31, 2010	$ 0.0	$ 0.0
Common stock, 100.0 shares authorized, $0.001 par value, 39.3 and 38.9 shares issued and outstanding as of March 31, 2011 and December 31, 2010, respectively	0.0	0.0
Additional paid-in capital	1,419.6	1,316.9
Retained earnings	812.0	718.9
Accumulated other comprehensive income (loss)	(0.7)	1.6
Total stockholders' equity	2,230.9	2,037.4
Total liabilities and stockholders' equity	$ 2,568.3	$ 2,390.4

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Millions	Mar. 31, 2011	Dec. 31, 2010
Condensed Consolidated Balance Sheets
Preferred stock, shares authorized	2.5	2.5
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares issued	0.0	0.0
Preferred stock, shares outstanding	0.0	0.0
Common stock, shares authorized	100.0	100.0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares issued	39.3	38.9
Common stock, shares outstanding	39.3	38.9

Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2010
Revenue:
Product	$ 324.5	$ 278.0
Service	63.6	50.6
Total revenue	388.1	328.6
Cost of revenue:
Product	84.8	68.0
Service	24.5	20.1
Total cost of revenue	109.3	88.1
Gross profit	278.8	240.5
Operating expenses:
Selling, general, and administrative	99.1	82.8
Research and development	31.4	28.0
Total operating expenses	130.5	110.8
Income from operations	148.3	129.7
Interest and other income, net	5.3	4.1
Income before taxes	153.6	133.8
Income tax expense	49.5	48.5
Net income	$ 104.1	$ 85.3
Net income per common share:
Basic	$ 2.66	$ 2.20
Diluted	$ 2.59	$ 2.12
Shares used in computing net income per common share:
Basic	39.1	38.8
Diluted	40.2	40.2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2010
Operating Activities:
Net income	$ 104.1	$ 85.3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	6.9	5.6
Amortization of intangible assets	4.4	3.9
Deferred income taxes	8.2	5.0
Income tax benefits from employee stock option plans	11.6	27.3
Excess tax benefit from stock-based compensation	(13.7)	(32.2)
Share-based compensation expense	32.1	26.8
Changes in operating assets and liabilities:
Accounts receivable	(13.1)	25.2
Inventory	(6.5)	(10.9)
Prepaids and other assets	(18.3)	(20.6)
Accounts payable	7.5	7.0
Accrued compensation and employee benefits	(20.2)	(19.1)
Deferred revenue	4.7	3.8
Accrued liabilities	(7.4)	8.5
Net cash provided by operating activities	100.3	115.6
Investing Activities:
Purchase of investments	(244.7)	(243.2)
Proceeds from sales and maturities of investments	266.7	111.8
Purchase of property and equipment and acquisition of intellectual property	(14.7)	(16.2)
Net cash provided by (used in) investing activities	7.3	(147.6)
Financing Activities:
Proceeds from issuance of common stock, net	59.5	92.5
Excess tax benefit from stock-based compensation	13.7	32.2
Repurchase and retirement of common stock	(11.6)
Net cash provided by financing activities	61.6	124.7
Effect of exchange rate changes on cash and cash equivalents	0.8	(0.5)
Net increase in cash and cash equivalents	170.0	92.2
Cash and cash equivalents, beginning of period	279.8	221.4
Cash and cash equivalents, end of period	$ 449.8	$ 313.6

Description of Business	3 Months Ended
Description of Business	Mar. 31, 2011
Description of Business
Description of Business	NOTE 1. DESCRIPTION OF BUSINESS Intuitive Surgical, Inc. designs, manufactures, and markets the da Vinci Surgical System, which is an advanced surgical system that the Company believes represents a new generation of surgery. The da Vinci Surgical System consists of a surgeon's console or consoles, a patient-side cart, a high performance vision system and proprietary "wristed" instruments. The da Vinci Surgical System translates the surgeon's natural hand movements on instrument controls at the console into corresponding micro-movements of instruments positioned inside the patient through small puncture incisions, or ports. The Company markets its products through sales representatives in the United States, and through a combination of sales representatives and distributors in its international markets.

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2011
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES *Basis of Presentation* In the opinion of management, the accompanying unaudited Condensed Consolidated Financial Statements ("financial statements") of Intuitive Surgical, Inc., and its wholly-owned subsidiaries have been prepared on a consistent basis with the December 31, 2010 audited Consolidated Financial Statements and include all adjustments, consisting of only normal recurring adjustments, necessary to fairly state the information set forth herein. These financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC"), and, therefore, omit certain information and footnote disclosure necessary to present the statements in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). These financial statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2010, which was filed on February 1, 2011. The results of operations for the first three months of fiscal 2011 are not indicative of the results to be expected for the entire fiscal year or any future periods. *New Accounting Standards Recently Adopted* No new accounting standards have been adopted since the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2010 was filed.

Cash, Cash Equivalents & Investments

3 Months Ended

Mar. 31, 2011

Cash, Cash Equivalents & Investments

Cash, Cash Equivalents & Investments

NOTE 3. CASH, CASH EQUIVALENTS & INVESTMENTS

The following tables summarize the Company's cash, cash equivalents and investments as of March 31, 2011 and December 31, 2010 (in millions):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
March 31, 2011
Cash and cash equivalents:
Cash	$	22.2	$	—	$	—		$	22.2
Cash equivalents		427.6		—		—			427.6

Total cash and cash equivalents	$	449.8	$	—	$	—		$	449.8

Available-for-sale investments:
Short-term
Commercial paper	$	89.9	$	0.0	$	0.0		$	89.9
Municipal notes		119.0		0.4		0.0			119.4
U.S. corporate debt		189.7		1.3		0.0			191.0
U.S. treasuries		75.8		0.1		0.0			75.9
U.S. government agencies		163.5		0.3		0.0			163.8

Total short-term	$	637.9	$	2.1	$	0.0		$	640.0

Long-term
Municipal notes	$	116.2	$	0.3	$	(4.0	)	$	112.5
U.S. corporate debt		297.8		1.4		(0.7	)		298.5
U.S. treasuries		25.9		0.0		0.0			25.9
U.S. government agencies		209.7		0.2		(0.5	)		209.4
Non-U.S. government securities		21.0		0.0		(0.1	)		20.9

Total long-term	$	670.6	$	1.9	$	(5.3	)	$	667.2


Total cash, cash equivalents and available-for-sale investments:	$	1,758.3	$	4.0	$	(5.3	)	$	1,757.0


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2010
Cash and cash equivalents:
Cash	$	20.1	$	0.0	$	0.0		$	20.1
Cash equivalents		259.7		0.0		0.0			259.7

Total cash and cash equivalents	$	279.8	$	0.0	$	0.0		$	279.8

Available-for-sale investments:
Short-term
Commercial paper	$	79.0	$	0.0	$	0.0		$	79.0
Municipal notes		111.8		0.4		0.0			112.2
U.S. corporate debt		174.1		1.3		0.0			175.4
U.S. treasuries		76.3		0.0		0.0			76.3
U.S. government agencies		187.4		0.3		0.0			187.7

Total short-term	$	628.6	$	2.0	$	0.0		$	630.6

Long-term
Municipal notes	$	143.4	$	0.3	$	(4.3	)	$	139.4
U.S. corporate debt		300.4		1.8		(0.9	)		301.3
U.S. treasuries		39.9		0.1		0.0			40.0
U.S. government agencies		196.7		0.3		(0.4	)		196.6
Non-U.S. government securities		21.2		0.1		(0.1	)		21.2

Total long-term	$	701.6	$	2.6	$	(5.7	)	$	698.5


Total cash, cash equivalents and available-for-sale investments	$	1,610.0	$	4.6	$	(5.7	)	$	1,608.9

The following table summarizes the maturities of the Company's cash equivalents and available-for-sale investments at March 31, 2011 (in millions):


	Amortized Cost		Fair Value
Mature in less than one year	$	1,065.6	$	1,067.6
Mature in one to five years		648.0		648.6
Mature in more than five years		22.5		18.6

Total	$	1,736.1	$	1,734.8

During the three months ended March 31, 2011 and 2010, realized gains or losses recognized on the sale of investments were not significant. As of March 31, 2011 and December 31, 2010, net unrealized gains (losses), net of tax of $(0.3) million and $1.3 million, respectively, were included in accumulated other comprehensive income in the accompanying unaudited Condensed Consolidated Balance Sheets. At March 31, 2011, the Company evaluated its gross unrealized losses, the majority of which are from auction-rate securities (ARS). The Company determined these unrealized losses to be temporary. Factors considered in determining whether a loss is temporary included the length of time and extent to which the investments fair value has been less than the cost basis, the financial condition and near-term prospects of the issuer, extent of the loss related to credit of the issuer, the expected cash flows from the security, the Company's intent to sell the security and whether or not the Company will be required to sell the security before the recovery of its amortized cost.

Fair Value Measurements

3 Months Ended

Mar. 31, 2011

Fair Value Measurements

Fair Value Measurements

NOTE 4. FAIR VALUE MEASUREMENTS

The Company measures certain financial assets, including cash equivalents, available-for-sale securities, trading securities and foreign currency derivatives at their fair value. The fair value of these financial assets was determined based on three levels of inputs, of which the first two are considered observable and the last unobservable, as follows:

Level 1 - Quoted prices in active markets for identical assets or liabilities.

Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The following tables represent the Company's fair value hierarchy for its financial assets and liabilities as of March 31, 2011 and December 31, 2010 (in millions):


	Fair Value Measurements at March 31, 2011 Using
Assets	Level 1		Level 2		Level 3		Total
Available-for-sale securities
Money Market funds	$	394.7	$	0.0	$	0.0	$	394.7
U.S. treasuries		101.8		0.0		0.0		101.8
Commercial paper		0.0		122.8		0.0		122.8
Corporate debt		0.0		489.5		0.0		489.5
U.S. government agencies		0.0		373.2		0.0		373.2
Non-U.S. government securities		0.0		20.9		0.0		20.9
Municipal notes		0.0		213.3		18.6		231.9

Total available-for-sale securities	$	496.5	$	1,219.7	$	18.6	$	1,734.8

Total assets measured at fair value	$	496.5	$	1,219.7	$	18.6	$	1,734.8


Liabilities
Foreign Currency Derivatives	$	0.0	$	1.5	$	0.0	$	1.5

Total liabilities measured at fair value	$	0.0	$	1.5	$	0.0	$	1.5


	Fair Value Measurements at December 31, 2010 Using
Assets	Level 1		Level 2		Level 3		Total
Available-for-sale securities
Money Market funds	$	211.2	$	0.0	$	0.0	$	211.2
U.S. treasuries		116.3		0.0		0.0		116.3
Commercial paper		0.0		122.5		0.0		122.5
Corporate debt		0.0		476.8		0.0		476.8
U.S. government agencies		0.0		389.2		0.0		389.2
Non-U.S. government securities		0.0		21.1		0.0		21.1
Municipal notes		0.0		233.1		18.6		251.7

Total available-for-sale securities	$	327.5	$	1,242.7	$	18.6	$	1,588.8

Foreign Currency Derivatives	$	0.0	$	0.2	$	0.0	$	0.2

Total assets measured at fair value	$	327.5	$	1,242.9	$	18.6	$	1,589.0


Liabilities
Foreign Currency Derivatives	$	0.0	$	2.1	$	0.0	$	2.1

Total liabilities measured at fair value	$	0.0	$	2.1	$	0.0	$	2.1

Level 2 securities are priced using quoted market prices for similar instruments, nonbinding market prices that are corroborated by observable market data, or discounted cash flow techniques. The Company's derivative instruments are primarily classified as Level 2 as they are not actively traded and are valued using pricing models that use observable market inputs. There have been no transfers between Level 1 and Level 2 measurements during the three months ended March 31, 2011. Level 3 assets consist of municipal bonds with an auction reset feature (ARS) whose underlying assets are student loans which are substantially backed by the federal government. Since the auctions for these securities have continued to fail since February 2008, these investments are not currently trading and therefore do not have a readily determinable fair value. The Company has valued the ARS using a discounted cash flow model based on Level 3 assumptions, including estimates of, based on data available as of March 31, 2011, interest rates, timing and amount of cash flows, credit and liquidity premiums and expected holding periods of the ARS.

Foreign currency derivative

Cash Flow Hedges

The Company enters into currency forward contracts as cash flow hedges to hedge certain forecasted revenue transactions denominated in currencies other than the U.S. dollar, primarily the Euro and GBP.

As of March 31, 2011 and December 31, 2010, the Company had notional amounts of €11 million and €21 million, respectively, of outstanding currency forward contracts entered into to hedge Euro dominated sales. The amounts reclassified to revenue as the related hedged revenue transactions were recognized for the three months ended March 31, 2011 and 2010 were not significant.

Other Derivatives Not Designated as Hedging Instruments

Other derivatives not designated as hedging instruments consist primarily of forward contracts that the Company uses to hedge intercompany balances and other monetary assets or liabilities denominated in currencies other than the U.S. dollar, primarily the Euro or GBP.

As of March 31, 2011, the Company had notional amounts of €19 million and £4 million outstanding currency forward contracts that were entered into to hedge non-functional currency denominated net monetary assets, compared to €26.0 million and £2.2 million at December 31, 2010. For the three months ended March 31, 2011 and 2010, the Company had recognized losses of approximately $2.2 million and gains of approximately $2.2 million, respectively, in interest and other income, net, related to derivative instruments used to hedge against balance sheet foreign currency exposures. This was offset by net foreign exchange gains of approximately $2.3 million and net foreign exchange losses of approximately $2.7 million during the three months ended March 31, 2011 and 2010, respectively, primarily related to the re-measurement of non-functional currency denominated net monetary assets.

Inventory

3 Months Ended

Mar. 31, 2011

Inventory

Inventory

NOTE 5. INVENTORY

The following table provides details of selected balance sheet items (in millions):


	March 31, 2011		December 31, 2010
Inventory
Raw materials	$	25.5	$	25.6
Work-in-process		3.4		2.5
Finished goods		64.4		58.7

Total	$	93.3	$	86.8

Contingencies	3 Months Ended
Contingencies	Mar. 31, 2011
Contingencies
Contingencies	NOTE 6. CONTINGENCIES On August 6, 2010, a purported class action lawsuit entitled Perlmutter v. Intuitive Surgical et al., No. CV10-3451, was filed against the Company and seven of the Company's current and former officers and directors in the United States District Court for the Northern District of California. The lawsuit seeks unspecified damages on behalf of a putative class of persons who purchased or otherwise acquired the Company's common stock between February 1, 2008 and January 7, 2009. The complaint alleges that the defendants violated federal securities laws by making allegedly false and misleading statements and omitting certain material facts in the Company's filings with the Securities and Exchange Commission. On February 15, 2011, the Police Retirement System of St. Louis was appointed Lead Plaintiff in the case pursuant to the Private Securities Litigation Reform Act of 1995. An amended complaint was filed on April 15, 2011, making allegations substantially similar to the allegations described above. On August 19, 2010, an alleged shareholder caused a purported shareholder's derivative lawsuit entitled Himmel v. Smith et al., No. 1-10-CV-180416, to be filed in the Superior Court of California for the County of Santa Clara naming the Company as a nominal defendant, and naming 14 of the Company's current and former officers and directors as defendants. The lawsuit seeks to recover, for the Company's benefit, unspecified damages purportedly sustained by the Company in connection with allegedly misleading statements and/or omissions made in connection with the Company's financial reporting for the period between February 1, 2008 and January 7, 2009. It also seeks a series of changes to the Company's corporate governance policies and an award of attorneys' fees. On September 15, 2010, another purported shareholder filed an essentially identical lawsuit entitled Applbaum v. Guthart et al., No. 1-10-CV-182645, in the same court against 15 of the Company's current and former officers and directors. On October 5, 2010 the court ordered that the two cases be consolidated for all purposes. By agreement with the plaintiffs, formal discovery has been stayed in the case. Due to the uncertainty surrounding the litigation process, the Company is unable to reasonably estimate the ultimate outcome of the above cases at this time, and therefore no amounts have been accrued related to the outcome of the cases above. Based on currently available information, the Company believes that it has meritorious defenses to the above actions and that the resolution of these cases is not likely to have a material adverse effect on the Company's business, financial position or future results of operations. The Company is also a party to various other legal actions that arose in the ordinary course of its business. The Company does not believe that any of these other legal actions will have a material adverse impact on its business, financial position or results of operations.

Stockholders' Equity

3 Months Ended

Mar. 31, 2011

Stockholders' Equity

Stockholders' Equity

NOTE 7. STOCKHOLDERS' EQUITY

Stock Repurchase Program

During the year ended December 31, 2010, the Company repurchased and retired approximately 0.7 million shares of its common stock at an average purchase price of $267.81 per share, for an aggregate purchase price of $198.6 million, through open market transactions. On February 3, 2011, the Board increased its authorization for stock repurchases to $400 million. During the three months ended March 31, 2011, the Company repurchased and retired approximately 36,000 shares of its common stock at an average purchase price of $323.11 per share, for an aggregate purchase price of $11.6 million, through open market transactions. As of March 31, 2011, the remaining authorized amount of stock repurchases under the Board-authorized stock repurchase program was approximately $388.5 million.

Comprehensive Income

The components of other comprehensive income, net of tax, are as follows (in millions):


	Three months ended March 31,
	2011			2010
Net income	$	104.1		$	85.3
Foreign currency translation gains (losses)		0.3			(0.2	)
Unrealized gains (losses) on derivative instruments, net of tax:
Unrealized gains (losses) on derivative instruments		(1.6	)		2.0
Reclassification adjustment for (gains) losses on derivative instruments recognized during the period		0.6			(0.9	)
Unrealized gains (losses) on available-for-sale securities, net of tax		(1.6	)		0.0

Total other comprehensive income	$	101.8		$	86.2

The components of accumulated other comprehensive income (loss) are as follows (in millions):


	March 31, 2011			December 31, 2010
Foreign currency translation gains	$	0.4		$	0.1
Accumulated net unrealized gains (losses) on derivatives, net of tax		(0.8	)		0.2
Accumulated net unrealized gains (losses) on available-for-sale securities, net of tax		(0.3	)		1.3

Total accumulated other comprehensive income (loss)	$	(0.7	)	$	1.6

Stock-Based Compensation

3 Months Ended

Mar. 31, 2011

Stock-Based Compensation

Stock-Based Compensation

NOTE 8. STOCK-BASED COMPENSATION

Stock Option Plans

A summary of stock option activity under all stock plans for the three months ended March 31, 2011 is presented as follows (in millions, except per share amounts):


				STOCK OPTIONS OUTSTANDING
	Shares Available for Grant			Number Outstanding			Weighted Average Exercise Price Per Share
Balance at December 31, 2010		1.4			4.8		$	209.03
Options authorized		0.1			—			—
Options granted		(1.1	)		1.1		$	338.65
Options exercised		0.0			(0.3	)	$	138.81
Options forfeited/expired		0.0			0.0			—

Balance at March 31, 2011		0.4			5.6		$	239.56

As of March 31, 2011, 2.4 million options were exercisable at a weighted-average price of $184.35 per share.

Employee Stock Purchase Plan

Under the Employee Stock Purchase Plan ("ESPP"), employees purchased approximately 92,072 shares for $10.4 million and 82,948 shares for $7.7 million during the three months ended March 31, 2011 and 2010, respectively.

Stock-based Compensation

The following table summarizes stock-based compensation charges (in millions):


	Three Months Ended March 31,
	2011		2010
Cost of sales - products	$	2.8	$	2.1
Cost of sales - services		2.5		1.9

Total cost of sales		5.3		4.0
Selling, general and administrative		20.2		17.8
Research and development		6.6		5.0

Stock-based compensation expense before income taxes		32.1		26.8
Income taxes		10.5		7.6

Stock-based compensation expense after income taxes	$	21.6	$	19.2

The fair value of each option grant and the fair value of the option component of the ESPP shares were estimated at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions, assuming no expected dividends:


	Stock Options						ESPP
	Three Months Ended March 31,						Three Months Ended March 31,
	2011			2010			2011			2010
Average risk free interest rate		2.33	%		2.32	%		0.37	%		0.49	%
Average expected term (years)		4.8			4.8			1.3			1.3
Average expected volatility		35	%		34	%		35	%		35	%
Weighted average fair value at grant date	$	114.76		$	111.30		$	97.07		$	99.34
Total stock-based compensation expense (in millions)	$	30.0		$	24.9		$	2.1		$	1.9

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2011
Income Taxes
Income Taxes	NOTE 9. INCOME TAXES Income tax expense for the three months ended March 31, 2011 was $49.5 million, or 32.2% of pre-tax income, compared with $48.5 million, or 36.2% of pre-tax income for the three months ended March 31, 2010. The effective tax rate for the three months ended March 31, 2011 differ from the U.S. federal statutory rate of 35% primarily due to the effect of income earned by certain of the Company's overseas entities being taxed at rates lower than the federal statutory rate, partially offset by state income taxes and non deductible stock option expenses. The effective tax rate for the three months ended March 31, 2010 differs from the U.S. federal statutory rate of 35% primarily due to state income taxes and non-deductible stock option expenses, partially offset by the effect of income earned by certain of the Company's overseas entities being taxed at rates lower than the federal statutory rate. The Company intends these foreign earnings to be indefinitely reinvested outside the United States. The decrease in effective tax rate for the three months ended March 31, 2011 compared with the three months ended March 31, 2010 is primarily related to the decrease in California tax after the adoption of single sales factor apportionment effective January 1, 2011, and an increase in foreign earnings taxed at lower rates relative to domestic income. As of March 31, 2011, the Company had total gross unrecognized tax benefits of approximately $82.8 million compared with approximately $78.9 million as of December 31, 2010, representing an increase of approximately $3.9 million during the three months ended March 31, 2011. Of the total gross unrecognized tax benefits, $78.5 million and $74.7 million as of March 31, 2011 and December 31, 2010, respectively, if recognized, would reduce the Company's effective tax rate in the period of recognition. Gross interest related to unrecognized tax benefit accrued was approximately $6.1 million and $5.5 million, respectively, as of March 31, 2011 and December 31, 2010. The Company files federal, state and foreign income tax returns in many jurisdictions in the United States and abroad. For U.S. federal and California income tax purposes, the statute of limitations currently remain open for all years since inception due to utilization of net operating losses and R&D credits generated in prior years.

Net Income Per Share

3 Months Ended

Mar. 31, 2011

Net Income Per Share

Net Income Per Share

NOTE 10. NET INCOME PER SHARE

The following table presents the computation of basic and diluted net income per share (in millions, except per share data):


	Three Months Ended March 31,
	2011		2010
Net income	$	104.1	$	85.3
Basic:
Weighted-average shares outstanding		39.1		38.8

Basic net income per share	$	2.66	$	2.20

Diluted:
Weighted-average shares outstanding used in basic calculation		39.1		38.8
Add common stock equivalents		1.1		1.4

Weighted-average shares used in computing diluted net income per shares		40.2		40.2

Diluted net income per share	$	2.59	$	2.12

Employee stock options to purchase approximately 2.1 million and 0.8 million weighted shares for the three months ended March 31, 2011 and 2010, respectively, were outstanding, but were not included in the computation of diluted net income per share because the effect of including such shares would have been antidilutive in the periods presented.

Summary of Significant Accounting Policies (Policy)	3 Months Ended
Summary of Significant Accounting Policies (Policy)	Mar. 31, 2011
Summary of Significant Accounting Policies
Basis of Presentation	*Basis of Presentation* In the opinion of management, the accompanying unaudited Condensed Consolidated Financial Statements ("financial statements") of Intuitive Surgical, Inc., and its wholly-owned subsidiaries have been prepared on a consistent basis with the December 31, 2010 audited Consolidated Financial Statements and include all adjustments, consisting of only normal recurring adjustments, necessary to fairly state the information set forth herein. These financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC"), and, therefore, omit certain information and footnote disclosure necessary to present the statements in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). These financial statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2010, which was filed on February 1, 2011. The results of operations for the first three months of fiscal 2011 are not indicative of the results to be expected for the entire fiscal year or any future periods.

Cash, Cash Equivalents & Investments (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2011

Dec. 31, 2010

Cash, Cash Equivalents & Investments

Cash, Cash Equivalents & Investments


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
March 31, 2011
Cash and cash equivalents:
Cash	$	22.2	$	—	$	—		$	22.2
Cash equivalents		427.6		—		—			427.6

Total cash and cash equivalents	$	449.8	$	—	$	—		$	449.8

Available-for-sale investments:
Short-term
Commercial paper	$	89.9	$	0.0	$	0.0		$	89.9
Municipal notes		119.0		0.4		0.0			119.4
U.S. corporate debt		189.7		1.3		0.0			191.0
U.S. treasuries		75.8		0.1		0.0			75.9
U.S. government agencies		163.5		0.3		0.0			163.8

Total short-term	$	637.9	$	2.1	$	0.0		$	640.0

Long-term
Municipal notes	$	116.2	$	0.3	$	(4.0	)	$	112.5
U.S. corporate debt		297.8		1.4		(0.7	)		298.5
U.S. treasuries		25.9		0.0		0.0			25.9
U.S. government agencies		209.7		0.2		(0.5	)		209.4
Non-U.S. government securities		21.0		0.0		(0.1	)		20.9

Total long-term	$	670.6	$	1.9	$	(5.3	)	$	667.2


Total cash, cash equivalents and available-for-sale investments:	$	1,758.3	$	4.0	$	(5.3	)	$	1,757.0


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2010
Cash and cash equivalents:
Cash	$	20.1	$	0.0	$	0.0		$	20.1
Cash equivalents		259.7		0.0		0.0			259.7

Total cash and cash equivalents	$	279.8	$	0.0	$	0.0		$	279.8

Available-for-sale investments:
Short-term
Commercial paper	$	79.0	$	0.0	$	0.0		$	79.0
Municipal notes		111.8		0.4		0.0			112.2
U.S. corporate debt		174.1		1.3		0.0			175.4
U.S. treasuries		76.3		0.0		0.0			76.3
U.S. government agencies		187.4		0.3		0.0			187.7

Total short-term	$	628.6	$	2.0	$	0.0		$	630.6

Long-term
Municipal notes	$	143.4	$	0.3	$	(4.3	)	$	139.4
U.S. corporate debt		300.4		1.8		(0.9	)		301.3
U.S. treasuries		39.9		0.1		0.0			40.0
U.S. government agencies		196.7		0.3		(0.4	)		196.6
Non-U.S. government securities		21.2		0.1		(0.1	)		21.2

Total long-term	$	701.6	$	2.6	$	(5.7	)	$	698.5


Total cash, cash equivalents and available-for-sale investments	$	1,610.0	$	4.6	$	(5.7	)	$	1,608.9

Schedule of Cash Equivalents and Available-for-Sale Securities by Maturity


	Amortized Cost		Fair Value
Mature in less than one year	$	1,065.6	$	1,067.6
Mature in one to five years		648.0		648.6
Mature in more than five years		22.5		18.6

Total	$	1,736.1	$	1,734.8

Fair Value Measurements (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2011

Dec. 31, 2010

Fair Value Measurements

Fair Value Hierarchy


	Fair Value Measurements at March 31, 2011 Using
Assets	Level 1		Level 2		Level 3		Total
Available-for-sale securities
Money Market funds	$	394.7	$	0.0	$	0.0	$	394.7
U.S. treasuries		101.8		0.0		0.0		101.8
Commercial paper		0.0		122.8		0.0		122.8
Corporate debt		0.0		489.5		0.0		489.5
U.S. government agencies		0.0		373.2		0.0		373.2
Non-U.S. government securities		0.0		20.9		0.0		20.9
Municipal notes		0.0		213.3		18.6		231.9

Total available-for-sale securities	$	496.5	$	1,219.7	$	18.6	$	1,734.8

Total assets measured at fair value	$	496.5	$	1,219.7	$	18.6	$	1,734.8


Liabilities
Foreign Currency Derivatives	$	0.0	$	1.5	$	0.0	$	1.5

Total liabilities measured at fair value	$	0.0	$	1.5	$	0.0	$	1.5


	Fair Value Measurements at December 31, 2010 Using
Assets	Level 1		Level 2		Level 3		Total
Available-for-sale securities
Money Market funds	$	211.2	$	0.0	$	0.0	$	211.2
U.S. treasuries		116.3		0.0		0.0		116.3
Commercial paper		0.0		122.5		0.0		122.5
Corporate debt		0.0		476.8		0.0		476.8
U.S. government agencies		0.0		389.2		0.0		389.2
Non-U.S. government securities		0.0		21.1		0.0		21.1
Municipal notes		0.0		233.1		18.6		251.7

Total available-for-sale securities	$	327.5	$	1,242.7	$	18.6	$	1,588.8

Foreign Currency Derivatives	$	0.0	$	0.2	$	0.0	$	0.2

Total assets measured at fair value	$	327.5	$	1,242.9	$	18.6	$	1,589.0


Liabilities
Foreign Currency Derivatives	$	0.0	$	2.1	$	0.0	$	2.1

Total liabilities measured at fair value	$	0.0	$	2.1	$	0.0	$	2.1

Inventory (Tables)

3 Months Ended

Mar. 31, 2011

Inventory

Inventory Selected Balance Sheet Items


	March 31, 2011		December 31, 2010
Inventory
Raw materials	$	25.5	$	25.6
Work-in-process		3.4		2.5
Finished goods		64.4		58.7

Total	$	93.3	$	86.8

Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2011

Stockholders' Equity

Components of Other Comprehensive Income


	Three months ended March 31,
	2011			2010
Net income	$	104.1		$	85.3
Foreign currency translation gains (losses)		0.3			(0.2	)
Unrealized gains (losses) on derivative instruments, net of tax:
Unrealized gains (losses) on derivative instruments		(1.6	)		2.0
Reclassification adjustment for (gains) losses on derivative instruments recognized during the period		0.6			(0.9	)
Unrealized gains (losses) on available-for-sale securities, net of tax		(1.6	)		0.0

Total other comprehensive income	$	101.8		$	86.2

Components of Accumulated Other Comprehensive Income (Loss)


	March 31, 2011			December 31, 2010
Foreign currency translation gains	$	0.4		$	0.1
Accumulated net unrealized gains (losses) on derivatives, net of tax		(0.8	)		0.2
Accumulated net unrealized gains (losses) on available-for-sale securities, net of tax		(0.3	)		1.3

Total accumulated other comprehensive income (loss)	$	(0.7	)	$	1.6

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2011

Stock-Based Compensation

Summary of Stock Option Activity


				STOCK OPTIONS OUTSTANDING
	Shares Available for Grant			Number Outstanding			Weighted Average Exercise Price Per Share
Balance at December 31, 2010		1.4			4.8		$	209.03
Options authorized		0.1			—			—
Options granted		(1.1	)		1.1		$	338.65
Options exercised		0.0			(0.3	)	$	138.81
Options forfeited/expired		0.0			0.0			—

Balance at March 31, 2011		0.4			5.6		$	239.56

Summary of Stock-Based Compensation Charges


	Three Months Ended March 31,
	2011		2010
Cost of sales - products	$	2.8	$	2.1
Cost of sales - services		2.5		1.9

Total cost of sales		5.3		4.0
Selling, general and administrative		20.2		17.8
Research and development		6.6		5.0

Stock-based compensation expense before income taxes		32.1		26.8
Income taxes		10.5		7.6

Stock-based compensation expense after income taxes	$	21.6	$	19.2

Black-Scholes Option Pricing Model, Weighted Average Assumptions


	Stock Options						ESPP
	Three Months Ended March 31,						Three Months Ended March 31,
	2011			2010			2011			2010
Average risk free interest rate		2.33	%		2.32	%		0.37	%		0.49	%
Average expected term (years)		4.8			4.8			1.3			1.3
Average expected volatility		35	%		34	%		35	%		35	%
Weighted average fair value at grant date	$	114.76		$	111.30		$	97.07		$	99.34
Total stock-based compensation expense (in millions)	$	30.0		$	24.9		$	2.1		$	1.9

Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2011

Net Income Per Share

Computation of Basic and Diluted Net Income Per Share


	Three Months Ended March 31,
	2011		2010
Net income	$	104.1	$	85.3
Basic:
Weighted-average shares outstanding		39.1		38.8

Basic net income per share	$	2.66	$	2.20

Diluted:
Weighted-average shares outstanding used in basic calculation		39.1		38.8
Add common stock equivalents		1.1		1.4

Weighted-average shares used in computing diluted net income per shares		40.2		40.2

Diluted net income per share	$	2.59	$	2.12

Cash, Cash Equivalents & Investments (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2010	Dec. 31, 2009
Statement [Line Items]
Cash, amortized cost	$ 22.2	$ 20.1
Cash, gross unrealized gains		0.0
Cash, gross unrealized losses		0.0
Cash, fair value	22.2	20.1
Cash equivalents, amortized cost	427.6	259.7
Cash equivalents, gross unrealized gains		0.0
Cash, equivalents, gross unrealized losses		0.0
Cash equivalents, fair value	427.6	259.7
Total cash and cash equivalents, amortized cost	449.8	279.8
Total cash and cash equivalents, gross unrealized gains		0.0
Total cash and cash equivalents, gross unrealized losses		0.0
Total cash and cash equivalents, fair value	449.8	279.8	$ 313.6	$ 221.4
Available-for-sale investments, fair value	1,734.8	1,588.8
Total cash, cash equivalents and available-for-sale investments, amortized cost	1,758.3	1,610.0
Cash, cash equivalents and available-for-sale investments, total gross unrealized gains	4.0	4.6
Cash, cash equivalents and available-for-sale investments, total gross unrealized losses	(5.3)	(5.7)
Total cash, cash equivalents and available-for-sale investments, fair value	1,757.0	1,608.9
Amortized Cost	1,736.1
Fair Value	1,734.8
Unrealized gain on investments	(0.3)	1.3
Non-U.S. Government Securities [Member]
Statement [Line Items]
Available-for-sale investments, fair value	20.9	21.1
Commercial Paper [Member]
Statement [Line Items]
Available-for-sale investments, fair value	122.8	122.5
Municipal Notes [Member]
Statement [Line Items]
Available-for-sale investments, fair value	231.9	251.7
U.S. Corporate Debt [Member]
Statement [Line Items]
Available-for-sale investments, fair value	489.5	476.8
U.S. Treasuries [Member]
Statement [Line Items]
Available-for-sale investments, fair value	101.8	116.3
U.S. Government Agencies [Member]
Statement [Line Items]
Available-for-sale investments, fair value	373.2	389.2
Short-Term Investments [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	637.9	628.6
Available-for-sale investments, gross unrealized gains	2.1	2.0
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	640.0	630.6
Short-Term Investments [Member] \| Commercial Paper [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	89.9	79.0
Available-for-sale investments, gross unrealized gains	0.0	0.0
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	89.9	79.0
Short-Term Investments [Member] \| Municipal Notes [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	119.0	111.8
Available-for-sale investments, gross unrealized gains	0.4	0.4
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	119.4	112.2
Short-Term Investments [Member] \| U.S. Corporate Debt [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	189.7	174.1
Available-for-sale investments, gross unrealized gains	1.3	1.3
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	191.0	175.4
Short-Term Investments [Member] \| U.S. Treasuries [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	75.8	76.3
Available-for-sale investments, gross unrealized gains	0.1	0.0
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	75.9	76.3
Short-Term Investments [Member] \| U.S. Government Agencies [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	163.5	187.4
Available-for-sale investments, gross unrealized gains	0.3	0.3
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	163.8	187.7
Long-Term Investments [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	670.6	701.6
Available-for-sale investments, gross unrealized gains	1.9	2.6
Available-for-sale investments, gross unrealized losses	(5.3)	(5.7)
Available-for-sale investments, fair value	667.2	698.5
Long-Term Investments [Member] \| Non-U.S. Government Securities [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	21.0	21.2
Available-for-sale investments, gross unrealized gains	0.0	0.1
Available-for-sale investments, gross unrealized losses	(0.1)	(0.1)
Available-for-sale investments, fair value	20.9	21.2
Long-Term Investments [Member] \| Municipal Notes [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	116.2	143.4
Available-for-sale investments, gross unrealized gains	0.3	0.3
Available-for-sale investments, gross unrealized losses	(4.0)	(4.3)
Available-for-sale investments, fair value	112.5	139.4
Long-Term Investments [Member] \| U.S. Corporate Debt [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	297.8	300.4
Available-for-sale investments, gross unrealized gains	1.4	1.8
Available-for-sale investments, gross unrealized losses	(0.7)	(0.9)
Available-for-sale investments, fair value	298.5	301.3
Long-Term Investments [Member] \| U.S. Treasuries [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	25.9	39.9
Available-for-sale investments, gross unrealized gains	0.0	0.1
Available-for-sale investments, gross unrealized losses	0.0	0.0
Available-for-sale investments, fair value	25.9	40.0
Long-Term Investments [Member] \| U.S. Government Agencies [Member]
Statement [Line Items]
Available-for-sale investments, amortized cost	209.7	196.7
Available-for-sale investments, gross unrealized gains	0.2	0.3
Available-for-sale investments, gross unrealized losses	(0.5)	(0.4)
Available-for-sale investments, fair value	209.4	$ 196.6
Mature in Less Than One Year [Member]
Statement [Line Items]
Amortized Cost	1,065.6
Fair Value	1,067.6
Mature in One to Five Years [Member]
Statement [Line Items]
Amortized Cost	648.0
Fair Value	648.6
Mature in More Than Five Years [Member]
Statement [Line Items]
Amortized Cost	22.5
Fair Value	$ 18.6

Fair Value Measurements (Narrative) (Details) € in Millions, £ in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2011 USD ($)	Mar. 31, 2010 USD ($)	Mar. 31, 2011 GBP (£)	Mar. 31, 2011 EUR (€)	Dec. 31, 2010 GBP (£)	Dec. 31, 2010 EUR (€)
Statement [Line Items]
Gains related to the remeasurement of balance sheet foreign currency exposures	$ 2.3	$ 2.2
Losses from derivative instruments used to hedge against balance sheet foreign currency exposures	$ 2.2	$ 2.7
Nonfunctional Currency Denominated Net Monetary Assets [Member]
Statement [Line Items]
Notional amount of currency forward contracts to hedge non-functional currency denominated net monetary assets			£ 4.0	€ 19.0	£ 2.2	€ 26.0
Euro Denominated Sales [Member]
Statement [Line Items]
Notional amount of currency forward contracts to hedge Euro and GBP dominated sales \| €				€ 11.0		€ 21.0

Fair Value Measurements (Fair Value Hierarchy) (Details) - USD ($) $ in Millions	Mar. 31, 2011	Dec. 31, 2010
Statement [Line Items]
Available-for-sale investments, fair value	$ 1,734.8	$ 1,588.8
Foreign currency derivatives, assets		0.2
Foreign currency derivatives, liabilities	1.5	2.1
Total assets measured at fair value	1,734.8	1,589.0
Total liabilities measured at fair value	1.5	2.1
Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	496.5	327.5
Foreign currency derivatives, assets		0.0
Foreign currency derivatives, liabilities	0.0	0.0
Total assets measured at fair value	496.5	327.5
Total liabilities measured at fair value	0.0	0.0
Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	1,219.7	1,242.7
Foreign currency derivatives, assets		0.2
Foreign currency derivatives, liabilities	1.5	2.1
Total assets measured at fair value	1,219.7	1,242.9
Total liabilities measured at fair value	1.5	2.1
Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	18.6	18.6
Foreign currency derivatives, assets		0.0
Foreign currency derivatives, liabilities	0.0	0.0
Total assets measured at fair value	18.6	18.6
Total liabilities measured at fair value	0.0	0.0
Money Market Funds [Member]
Statement [Line Items]
Available-for-sale investments, fair value	394.7	211.2
Money Market Funds [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	394.7	211.2
Money Market Funds [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Money Market Funds [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Treasuries [Member]
Statement [Line Items]
Available-for-sale investments, fair value	101.8	116.3
U.S. Treasuries [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	101.8	116.3
U.S. Treasuries [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Treasuries [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Commercial Paper [Member]
Statement [Line Items]
Available-for-sale investments, fair value	122.8	122.5
Commercial Paper [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Commercial Paper [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	122.8	122.5
Commercial Paper [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Corporate Debt [Member]
Statement [Line Items]
Available-for-sale investments, fair value	489.5	476.8
U.S. Corporate Debt [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Corporate Debt [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	489.5	476.8
U.S. Corporate Debt [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Government Agencies [Member]
Statement [Line Items]
Available-for-sale investments, fair value	373.2	389.2
U.S. Government Agencies [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
U.S. Government Agencies [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	373.2	389.2
U.S. Government Agencies [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Non-U.S. Government Securities [Member]
Statement [Line Items]
Available-for-sale investments, fair value	20.9	21.1
Non-U.S. Government Securities [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Non-U.S. Government Securities [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	20.9	21.1
Non-U.S. Government Securities [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Municipal Notes [Member]
Statement [Line Items]
Available-for-sale investments, fair value	231.9	251.7
Municipal Notes [Member] \| Level 1 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	0.0	0.0
Municipal Notes [Member] \| Level 2 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	213.3	233.1
Municipal Notes [Member] \| Level 3 [Member]
Statement [Line Items]
Available-for-sale investments, fair value	$ 18.6	$ 18.6

Inventory (Details) - USD ($) $ in Millions	Mar. 31, 2011	Dec. 31, 2010
Inventory
Raw materials	$ 25.5	$ 25.6
Work-in-process	3.4	2.5
Finished goods	64.4	58.7
Total	$ 93.3	$ 86.8

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Dec. 31, 2010	Feb. 03, 2011
Stockholders' Equity
Repurchase and retirement of common stock (shares)	36,000		700,000
Average purchase price per share under repurchase program	$ 323.11		$ 267.81
Aggregate repurchase price of common stock	$ 11.6		$ 198.6
Remaining authorized amount of stock repurchases	388.5
Increase (decrease) in share repurchase authorization				$ 400.0
Net income	104.1	85.3
Foreign currency translation gains (losses)	0.3	(0.2)
Unrealized gains (losses) on derivative instruments	(1.6)	2.0
Reclassification adjustment for (gains) losses on derivative instruments recognized during the period	0.6	(0.9)
Unrealized gains (losses) on available-for-sale securities, net of tax	(1.6)	0.0
Total other comprehensive income	101.8	$ 86.2
Foreign currency translation gains	0.4		0.1
Accumulated net unrealized gains (losses) on derivatives, net of tax	(0.8)		0.2
Accumulated net unrealized gains (losses) on available-for-sale securities, net of tax	(0.3)		1.3
Total accumulated other comprehensive income (loss)	$ (0.7)		$ 1.6

Stock-Based Compensation (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2011 USD ($) $ / shares shares	Mar. 31, 2010 USD ($) $ / shares shares
Statement [Line Items]
Balance, shares available for grant	1,400,000
Options authorized, shares available for grant	100,000
Options granted, shares available for grant	(1,100,000)
Options exercised, shares available for grant	0
Options forfeited/expired, shares available for grant	0
Balance, shares available for grant	400,000
Balance, number of options outstanding	4,800,000
Options authorized, number outstanding
Options granted, number outstanding	1,100,000
Options exercised, number outstanding	(300,000)
Options forfeited/expired, number outstanding	0
Balance, number of options outstanding	5,600,000
Balance, number of options outstanding, weighted average exercise price per share \| $ / shares	$ 209.03
Options authorized, weighted average exercise price per share \| $ / shares
Options granted, weighted average exercise price per share \| $ / shares	338.65
Options exercised, weighted average exercise price per share \| $ / shares	138.81
Options forfeited/expired, weighted average exercise price per share \| $ / shares
Balance, number of options outstanding, weighted average exercise price per share \| $ / shares	$ 239.56
Options exercisable, number of shares	2,400,000
Options exercisable, weighted-average exercise price per share \| $ / shares	$ 184.35
Employee stock purchase plan, shares issued	92,072	82,948
Employee stock purchase plan, value of shares issued \| $	$ 10.4	$ 7.7
Stock Option Plans [Member]
Statement [Line Items]
Average risk free interest rate	2.33%	2.32%
Average expected term (years)	4.8	4.8
Average expected volatility	35.00%	34.00%
Weighted average fair value at grant date \| $ / shares	$ 114.76	$ 111.30
Total stock-based compensation expense \| $	$ 30.0	$ 24.9
Employee Stock Purchase Plan [Member]
Statement [Line Items]
Average risk free interest rate	0.37%	0.49%
Average expected term (years)	1.3	1.3
Average expected volatility	35.00%	35.00%
Weighted average fair value at grant date \| $ / shares	$ 97.07	$ 99.34
Total stock-based compensation expense \| $	$ 2.1	$ 1.9
Cost of Sales - Products [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	2.8	2.1
Cost of Sales - Services [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	2.5	1.9
Total Cost of Sales [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	5.3	4.0
Selling, General and Administrative [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	20.2	17.8
Research and Development [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	6.6	5.0
Stock-Based Compensation Expense before Income Taxes [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	32.1	26.8
Income Taxes [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	10.5	7.6
Stock-based Compensation Expense after Income Taxes [Member]
Statement [Line Items]
Total stock-based compensation expense \| $	$ 21.6	$ 19.2

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2011	Mar. 31, 2010	Dec. 31, 2010
Income Taxes
Income tax expense	$ 49.5	$ 48.5
Tax expense, percentage of pre-tax income	32.20%	36.20%
Federal statutory tax rate	35.00%	35.00%
Total gross unrecognized tax benefits	$ 82.8		$ 78.9
Unrecognized tax benefits, period increase	3.9
Unrecognized tax benefits that would reduce Company's effective tax rate	78.5		74.7
Gross interest related to unrecognized tax benefits accrued	$ 6.1		$ 5.5

Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2010
Net Income Per Share
Net income	$ 104.1	$ 85.3
Weighted-average shares outstanding	39.1	38.8
Basic net income per share	$ 2.66	$ 2.20
Weighted-average shares outstanding used in basic calculation	39.1	38.8
Add common stock equivalents	1.1	1.4
Weighted-average shares used in computing diluted net income per share	40.2	40.2
Diluted net income per share	$ 2.59	$ 2.12
Employee stock options excluded from computation of diluted net income per share because the effect of including such shares would have been antidilutive	2.1	0.8