Intuitive Surgical (ISRG) 10-Q19 Oct 202020 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2020	Oct. 14, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	000-30713
Entity Registrant Name	Intuitive Surgical, Inc.
State or Other Jurisdiction of Incorporation or Organization	DE
I.R.S. Employer Identification No.	77-0416458
Entity Address, Address Line One	1020 Kifer Road
Entity Address, City or Town	Sunnyvale
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94086
City Area Code	408
Local Phone Number	523-2100
Title of each class	Common Stock, par value $0.001 per share
Trading Symbol(s)	ISRG
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		117,555,484
Entity Central Index Key	0001035267
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 1,370.6	$ 1,167.6
Short-term investments	3,347.6	2,054.1
Accounts receivable, net	588.6	645.2
Inventory	662.9	595.5
Prepaids and other current assets	330.6	200.2
Total current assets	6,300.3	4,662.6
Property, plant, and equipment, net	1,509.7	1,272.9
Long-term investments	1,643.2	2,623.5
Deferred tax assets	360.3	425.6
Intangible and other assets, net	467.7	441.4
Goodwill	336.3	307.2
Total assets	10,617.5	9,733.2
Current liabilities:
Accounts payable	116	123.5
Accrued compensation and employee benefits	175.2	251.6
Deferred revenue	327.8	337.8
Other accrued liabilities	275.7	317.3
Total current liabilities	894.7	1,030.2
Other long-term liabilities	436.1	418.3
Total liabilities	1,330.8	1,448.5
Contingencies (Note 8)
Stockholders’ equity:
Preferred stock, 2.5 shares authorized, $0.001 par value, issuable in series; no shares issued and outstanding as of June 30, 2020, and December 31, 2019	0	0
Common stock, 300.0 shares authorized, $0.001 par value, 117.0 shares and 116.0 shares issued and outstanding as of June 30, 2020, and December 31, 2019, respectively	0.1	0.1
Additional paid-in capital	6,304.3	5,756.8
Retained earnings	2,937.2	2,494.5
Accumulated other comprehensive income (loss)	16.2	12.4
Total Intuitive Surgical, Inc. stockholders’ equity	9,257.8	8,263.8
Noncontrolling interest in joint venture	28.9	20.9
Total stockholders’ equity	9,286.7	8,284.7
Total liabilities and stockholders’ equity	$ 10,617.5	$ 9,733.2

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	2,500,000	2,500,000
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares issued (in shares)	117,500,000	116,000,000
Common stock, shares outstanding (in shares)	117,500,000	116,000,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Total revenue	$ 1,077.7	$ 1,128.2	$ 3,029.3	$ 3,200.8
Cost of revenue:
Total cost of revenue	353.4	342.6	1,063.9	986.6
Gross profit	724.3	785.6	1,965.4	2,214.2
Operating expenses:
Selling, general and administrative	298.9	284	886.1	836.6
Research and development	155	135.9	445.3	400.7
Total operating expenses	453.9	419.9	1,331.4	1,237.3
Income from operations	270.4	365.7	634	976.9
Interest and other income, net	84.8	33.3	136.5	93.6
Income before taxes	355.2	399	770.5	1,070.5
Income tax expense	38.4	0.3	67.3	51.4
Net income	316.8	398.7	703.2	1,019.1
Less: net loss attributable to noncontrolling interest in joint venture	2.9	1.9	7.8	(2.5)
Net income attributable to Intuitive Surgical, Inc.	$ 313.9	$ 396.8	$ 695.4	$ 1,021.6
Net income per share attributable to Intuitive Surgical, Inc.:
Basic (in dollars per share)	$ 2.68	$ 3.44	$ 5.95	$ 8.86
Diluted (in dollars per share)	$ 2.60	$ 3.33	$ 5.80	$ 8.56
Shares used in computing net income per share attributable to Intuitive Surgical, Inc.:
Basic (in shares)	117.3	115.4	116.8	115.3
Diluted (in shares)	120.6	119.3	120	119.4
Total comprehensive income attributable to Intuitive Surgical, Inc.	$ 307.8	$ 398.5	$ 699.2	$ 1,052.7
Product
Revenue:
Total revenue	898.4	944.8	2,521	2,666.9
Cost of revenue:
Total cost of revenue	287.7	277.3	868.2	807.1
Service
Revenue:
Total revenue	179.3	183.4	508.3	533.9
Cost of revenue:
Total cost of revenue	$ 65.7	$ 65.3	$ 195.7	$ 179.5

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Statement of Cash Flows [Abstract]
Net income	$ 703.2	$ 1,019.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and loss on disposal of property, plant, and equipment	159.1	108
Amortization of intangible assets	37.3	31.2
Loss (gain) on investments, accretion, and amortization, net	(64.2)	(6.6)
Deferred income taxes	71.9	(8.3)
Share-based compensation expense	292.3	246.6
Amortization of contract acquisition assets	12.4	9.2
Changes in operating assets and liabilities, net of effects of acquisition:
Accounts receivable	57.2	50.6
Inventory	(177)	(293.4)
Prepaids and other assets	(118.8)	(95.1)
Accounts payable	(3.9)	24.7
Accrued compensation and employee benefits	(76.4)	(6.8)
Deferred revenue	(9.2)	5.8
Other liabilities	(26.6)	(39.5)
Net cash provided by operating activities	857.3	1,045.5
Investing activities:
Purchase of investments	(3,023.2)	(2,543.4)
Proceeds from Sale of Investments	800.7	82.1
Proceeds from maturities of investments	1,933.5	2,028.5
Purchase of property, plant, and equipment and intellectual property	(279.6)	(283.6)
Acquisition of businesses, net of cash	(37.7)	(31.8)
Net cash provided by (used in) investing activities	(606.3)	(748.2)
Financing activities:
Proceeds from issuance of common stock relating to employee stock plans	267.9	205.7
Taxes paid related to net share settlement of equity awards	(165.3)	(152.9)
Repurchase of common stock	(100)	(269.5)
Capital contribution from noncontrolling interest	0	10
Payment of deferred purchase consideration	(48.5)	(12.5)
Net cash provided by (used in) financing activities	(45.9)	(219.2)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(2)	(2.9)
Net increase (decrease) in cash, cash equivalents, and restricted cash	203.1	75.2
Cash, cash equivalents, and restricted cash, beginning of period	1,182.6	909.4
Cash, cash equivalents, and restricted cash, end of period	$ 1,385.7	$ 984.6

DESCRIPTION OF THE BUSINESS

DESCRIPTION OF THE BUSINESS	9 Months Ended
DESCRIPTION OF THE BUSINESS	Sep. 30, 2020
Accounting Policies [Abstract]
DESCRIPTION OF THE BUSINESS	DESCRIPTION OF THE BUSINESS Intuitive Surgical, Inc. (“Intuitive” or the “Company”) develops, manufactures, and markets the da Vinci ® Surgical System and the Ion TM endoluminal system. The Company’s products and related services enable physicians and healthcare providers to improve the quality of and access to minimally invasive care. The da Vinci Surgical System consists of a surgeon console or consoles, a patient-side cart, a high-performance vision system, and proprietary instruments and accessories. The Ion endoluminal system is a flexible, robotic-assisted, catheter-based platform that utilizes instruments and accessories for lung biopsies.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Sep. 30, 2020
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	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 and majority-owned subsidiaries have been prepared on a consistent basis with the audited Consolidated Financial Statements for the fiscal year ended December 31, 2019, and include all adjustments, consisting of only normal, recurring adjustments, necessary to fairly state the information set forth herein. The 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 Financial Statements in accordance with United States (“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, 2019, which was filed with the SEC on February 7, 2020. The results of operations for the first nine months of fiscal year 2020 are not necessarily indicative of the results to be expected for the entire fiscal year or any future periods. The Financial Statements include the results and the balances of the Company’s majority-owned joint venture (referred to herein as the “Joint Venture”) with Shanghai Fosun Pharmaceutical (Group) Co., Ltd. (“Fosun Pharma”). The Company holds a controlling financial interest in the Joint Venture, and the noncontrolling interest is reflected as a separate component of consolidated stockholders’ equity. The noncontrolling interest’s share of the earnings in the Joint Venture is presented separately in the condensed consolidated statements of income. Risks and Uncertainties The Company is subject to additional risks and uncertainties due to the COVID-19 pandemic. The extent of the impact on the Company's business is highly uncertain and difficult to predict, as the response to the pandemic is in its early stages with no vaccine or new effective treatments available as of the date of this filing. The Company's customers are diverting resources to treat COVID-19 patients and deferring elective surgical procedures, both of which are likely to impact the Company's customers' ability to meet their obligations, including to the Company. Furthermore, capital markets and economies worldwide have been negatively impacted by the COVID-19 pandemic, and it is possible that the impact could cause an extended local and/or global economic recession. Such economic disruption could have a material adverse effect on our business as hospitals curtail and reduce capital and overall spending. Policymakers around the globe have responded with fiscal policy actions to support the healthcare industry and economy as a whole. However, the magnitude and overall effectiveness of these actions remains uncertain. The severity of the impact of the COVID-19 pandemic on the Company's business will depend on a number of factors, including, but not limited to, the duration and severity of the pandemic and the extent and severity of the impact on the Company's customers, all of which are uncertain and cannot be predicted. The Company's future results of operations and liquidity could be materially adversely affected by delays in payments of outstanding receivables, supply chain disruptions, uncertain or reduced demand, and the impact of any initiatives or programs that the Company may undertake to address financial and operational challenges faced by its customers. As of the date of issuance of these Financial Statements, the extent to which the COVID-19 pandemic may materially adversely affect the Company's financial condition, liquidity, or results of operations is uncertain. Customer Relief Program During the second quarter of 2020, the Company introduced a series of programs to provide financial relief to customers (the “Customer Relief Program”). As part of the Customer Relief Program, the Company is providing its customers service fee credits, extending payment terms, and deferring payments related to Intuitive System Leasing arrangements. The Company does not plan on extending the Customer Relief Program beyond the third quarter of 2020. Service fee credits . As part of the Customer Relief Program, the Company provided service fee credits to customers based on the reduction in the utilization of their systems during the second and third quarters of 2020 relative to a pre-COVID-19 level baseline. The Company reflected the service fee credits as a reduction of service revenue and accounts receivable in the quarter they were earned by its customers. The service fee credit program resulted in a $59 million and $23 million decrease in service revenue in the second and third quarters of 2020, respectively. Short-term payment relief . In response to the COVID-19 pandemic, the Company has introduced a payment deferral program to provide financial relief to qualified customers. This relief extended payment terms up to 180 days for qualified and creditworthy customers. The Company also introduced a lease payment deferral program in which creditworthy customers with active Intuitive System Leasing arrangements may elect to defer lease payments up to five months that are payable at the end of the lease by extending the lease term by five months. This program does not result in substantial increases in the rights of the lessor or the obligations of the lessee, and the Company elected to apply the relief provided by the Financial Accounting Standards Board (“FASB”) FAQ on accounting for COVID-19 and market volatility by not applying the lease modification guidance in ASC 842 to the lease arrangements affected by the deferrals and lease extensions. For operating lease arrangements where the lease term is extended by adding the deferred period to the end of the contract, the Company recalculated the straight-line revenue based on the revised terms, consistent with the treatment accepted by the FASB FAQ on accounting for COVID-19. For its sales-type lease arrangements impacted, the Company accounted for the deferral in the timing of lease payments as if there were no changes in the lease contract, consistent with the treatment accepted by the FASB FAQ on accounting for COVID-19. While the short-term payment relief offered did not have a material impact on the results of operations, the Company has deferred $14 million of lease billings and extended payment terms associated with $181 million of billings since the start of the program, of which $85 million remained outstanding as of September 30, 2020. Recently Adopted Accounting Pronouncements Credit Losses In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. The Company adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment, if any, to the opening balance of retained earnings to be recognized on the date of adoption with prior periods not restated. The cumulative-effect adjustment recorded on January 1, 2020, was not material. Please see the description of the Company’s “Credit Losses” accounting policy in the “Significant Accounting Policies” section below. Significant Accounting Policies With the exception of the aspects within the Customer Relief Program noted above and the change for the accounting of credit losses as a result of the adoption of Topic 326, there have been no new or material changes to the significant accounting policies discussed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019, that are of significance, or potential significance, to the Company. Credit Losses Trade accounts receivable. The allowance for doubtful accounts is based on the Company’s assessment of the collectibility of customer accounts. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the accounts receivable balances, and current economic conditions that may affect a customer’s ability to pay. For the three and nine months ended September 30, 2020, and 2019, bad debt expense was not significant. Net investment in sales-type leases. The Company enters into sales-type leases with certain qualified customers to purchase its systems. Sales-type leases have terms that generally range from 24 to 84 months and are usually collateralized by a security interest in the underlying assets. The allowance for loan loss is based on the Company's assessment of current expected lifetime loss on lease receivables. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the lease receivable balances, and current economic conditions that may affect a customer's ability to pay. Lease receivables are considered past due 90 days after invoice. The Company manages the credit risk in net investment in sales-type leases using a number of factors, including, but not limited to the following: size of operations; profitability, liquidity, and debt ratios; payment history; and past due amounts. The Company also uses credit scores obtained from external providers as a key credit quality indicator for the purposes of determining credit quality. The following table presents credit quality by class of net investment in sales-type lease as of September 30, 2020. The following table summarizes the amortized cost basis by year of origination and credit quality indicator as of September 30, 2020 (in millions): 2020 2019 2018 2017 2016 Prior Net Investment Credit Rating: High $ 43.1 $ 37.0 $ 14.6 $ 7.9 $ 2.4 $ 1.4 $ 106.4 Moderate 48.4 34.8 21.6 6.8 2.9 0.4 114.9 Low 6.6 1.0 0.4 — 1.0 — 9.0 Total $ 98.1 $ 72.8 $ 36.6 $ 14.7 $ 6.3 $ 1.8 $ 230.3 For the three and nine months ended September 30, 2020, and 2019, credit losses related to net investment in sales-type leases were not significant. Available-for-sale debt securities. The Company's investment portfolio at any point in time contains investments in U.S. treasury and U.S. government agency securities, taxable and tax-exempt municipal notes, corporate notes and bonds, commercial paper, non-U.S. government agency securities, cash deposits, and money market funds. The Company segments its portfolio based on the underlying risk profiles of the securities and have a zero loss expectation for U.S. treasury and U.S. government agency securities. The Company regularly reviews the securities in an unrealized loss position and evaluates the current expected credit loss by considering factors such as historical experience, market data, issuer-specific factors, and current economic conditions. For the three and nine months ended September 30, 2020, the credit losses related to available-for-sales debt securities were not significant. For both the three and nine months ended September 30, 2019, there were no credit losses recognized related to available-for-sales debt securities. The Company's exposure to credit losses may increase if its customers are adversely affected by changes in healthcare laws, coverage, and reimbursement, economic pressures or uncertainty associated with local or global economic recessions, disruption associated with the current COVID-19 pandemic, or other customer-specific factors. Although the Company has historically not experienced significant credit losses, it is possible that there could be a material adverse impact from potential adjustments of the carrying amount of lease and trade receivables as hospital cash flows are impacted by their response to the COVID-19 pandemic and deferral of elective surgical procedures.

FINANCIAL INSTRUMENTS

FINANCIAL INSTRUMENTS	9 Months Ended
FINANCIAL INSTRUMENTS	Sep. 30, 2020
Investments, All Other Investments [Abstract]
FINANCIAL INSTRUMENTS	FINANCIAL INSTRUMENTS Cash, Cash Equivalents, and Investments The following tables summarize the Company’s cash and available-for-sale marketable securities’ amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category reported as cash and cash equivalents, short-term investments, or long-term investments as of September 30, 2020, and December 31, 2019 (in millions): Reported as: Amortized Gross Gross Allowance for Credit Loss Fair Cash and Short- Long- September 30, 2020 Cash $ 508.7 $ — $ — $ — $ 508.7 $ 508.7 $ — $ — Level 1: Money market funds 745.5 — — — 745.5 745.5 — — U.S. treasuries 2,337.5 28.9 — — 2,366.4 108.5 1,405.2 852.7 Subtotal 3,083.0 28.9 — — 3,111.9 854.0 1,405.2 852.7 Level 2: Commercial paper 554.1 — — — 554.1 5.0 549.1 — Corporate debt securities 1,514.8 15.1 (0.2) — 1,529.7 2.9 1,135.0 391.8 U.S. government agencies 550.2 3.0 — — 553.2 — 228.0 325.2 Non-U.S. government securities 9.5 — — — 9.5 — 4.5 5.0 Municipal securities 92.1 2.2 — — 94.3 — 25.8 68.5 Subtotal 2,720.7 20.3 (0.2) — 2,740.8 7.9 1,942.4 790.5 Total assets measured at fair value $ 6,312.4 $ 49.2 $ (0.2) $ — $ 6,361.4 $ 1,370.6 $ 3,347.6 $ 1,643.2 Reported as: Amortized Gross Gross Fair Cash and Short- Long- December 31, 2019 Cash $ 413.1 $ — $ — $ 413.1 $ 413.1 $ — $ — Level 1: Money market funds 726.8 — — 726.8 726.8 — — U.S. treasuries 1,935.8 9.7 (0.4) 1,945.1 — 890.8 1,054.3 Subtotal 2,662.6 9.7 (0.4) 2,671.9 726.8 890.8 1,054.3 Level 2: Commercial paper 165.1 — — 165.1 25.5 139.6 — Corporate debt securities 2,096.1 16.8 (0.2) 2,112.7 — 798.5 1,314.2 U.S. government agencies 418.3 1.1 (0.2) 419.2 — 209.6 209.6 Non-U.S. government securities 4.5 — — 4.5 — 4.5 — Municipal securities 58.4 0.3 — 58.7 2.2 11.1 45.4 Subtotal 2,742.4 18.2 (0.4) 2,760.2 27.7 1,163.3 1,569.2 Total assets measured at fair value $ 5,818.1 $ 27.9 $ (0.8) $ 5,845.2 $ 1,167.6 $ 2,054.1 $ 2,623.5 The following table summarizes the contractual maturities of the Company’s cash equivalents and available-for-sale investments (excluding cash and money market funds), as of September 30, 2020 (in millions): Amortized Fair Mature in less than one year $ 3,452.0 $ 3,464.0 Mature in one to five years 1,606.2 1,643.2 Total $ 5,058.2 $ 5,107.2 Actual maturities may differ from contractual maturities, because certain borrowers have the right to call or prepay certain obligations. Gross realized gains recognized on the sale of investments were not material and $8.3 million for the three and nine months ended September 30, 2020, respectively, and not material for the prior year comparative periods. Gross realized losses recognized on the sale of investments were not material for the periods presented. Equity Investments The Company holds equity investments with readily determinable fair values and equity investments without readily determinable fair values. The Company generally recognizes equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The following table is a summary of the activity related to equity investments (in millions): Reported as: December 31, 2019 Changes in Fair Value (1) Sales/Purchases/Others (2) September 30, 2020 Carrying Value Prepaids and other current assets Intangible and other assets, net Equity investments with readily determinable value (Level 1) $ — $ 6.1 $ 59.8 $ 65.9 $ 65.9 $ — Equity investments without readily determinable value (Level 2) $ 24.6 $ 61.5 $ (58.2) $ 27.9 $ — $ 27.9 (1) Recorded in Interest and other income, net. (2) Other includes conversion of certain equity investments without readily determinable value to equity investments with readily determinable value. The Company recognized a $61.5 million increase in fair value, which was reflected in Interest and other income, net, due to changes in observable prices for certain equity investments that had been held at cost, because they lacked readily determinable market values. A total of $44.8 million of this increase in fair value was related to an equity investment in preferred shares of InTouch Technologies, Inc. ("InTouch"), an entity that was acquired by Teladoc Health, Inc. ("Teladoc"), a publicly traded company, on July 1, 2020. Upon acquisition, the Company's shares were converted to shares in Teladoc, which have a readily determinable value. The Company is restricted from selling these shares for a period of six months. There were no decreases in fair value reflected in net income due to impairments. Foreign Currency Derivatives The objective of the Company’s hedging program is to mitigate the impact of changes in currency exchange rates on net cash flow from foreign currency-denominated sales, expenses, intercompany balances, and other monetary assets or liabilities denominated in currencies other than the U.S. dollar (“USD”). The terms of the Company’s derivative contracts are generally twelve months or shorter. The derivative assets and liabilities are measured using Level 2 fair value inputs. 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 USD, primarily the Euro (“EUR”), the British Pound (“GBP”), the Japanese Yen (“JPY”), and the Korean Won (“KRW”). The Company also enters into currency forward contracts as cash flow hedges to hedge certain forecasted expense transactions denominated in EUR and the Swiss Franc (“CHF”). For these derivatives, the Company reports the unrealized after-tax gain or loss from the hedge as a component of accumulated other comprehensive income/(loss) in stockholders’ equity and reclassifies the amount into earnings in the same period in which the hedged transaction affects earnings. The amounts reclassified to revenue and expenses related to the hedged transactions and the ineffective portions of cash flow hedges were not material for the periods presented. 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 USD, primarily the EUR, GBP, JPY, KRW, CHF, Indian Rupee ("INR"), Mexican Peso ("MXN"), Chinese Yuan ("CNY"), and New Taiwan Dollar ("TWD"). These derivative instruments are used to hedge against balance sheet foreign currency exposures. The related gains and losses were as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Recognized gains/(losses) in interest and other income, net $ (5.0) $ 4.2 $ (3.2) $ 5.7 Foreign exchange gains/(losses) related to balance sheet re-measurement $ 5.9 $ (3.8) $ (1.1) $ (3.5) The notional amounts for derivative instruments provide one measure of the transaction volume. Total gross notional amounts (in USD) for outstanding derivatives and the aggregate gross fair value at the end of each period were as follows (in millions): Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments September 30, December 31, 2019 September 30, December 31, 2019 Notional amounts: Forward contracts $ 144.0 $ 154.5 $ 260.9 $ 227.2 Gross fair value recorded in: Prepaids and other current assets $ 0.9 $ 1.3 $ 0.9 $ 2.2 Other accrued liabilities $ 1.8 $ 0.5 $ 1.3 $ 0.7

BALANCE SHEET DETAILS AND OTHER

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION	9 Months Ended
BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION	BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION Balance Sheet Details The following tables provide details of selected balance sheet line items (in millions): As of Inventory September 30, December 31, Raw materials $ 197.1 $ 211.0 Work-in-process 66.5 75.9 Finished goods 399.3 308.6 Total inventory $ 662.9 $ 595.5 As of Prepaids and other current assets September 30, December 31, Prepaid taxes $ 103.3 $ 28.0 Equity investments 65.9 — Net investment in sales-type leases – short-term 68.7 63.1 Other prepaids and other current assets 92.7 109.1 Total prepaids and other current assets $ 330.6 $ 200.2 As of Other accrued liabilities–short-term September 30, December 31, Taxes payable $ 35.3 $ 37.9 Current portion of deferred purchase consideration payments 39.0 35.7 Current portion of contingent consideration 24.8 44.5 Other accrued liabilities 176.6 199.2 Total other accrued liabilities–short-term $ 275.7 $ 317.3 As of Other long-term liabilities September 30, December 31, Income taxes–long-term $ 306.5 $ 258.6 Deferred revenue–long-term 30.3 27.4 Other long-term liabilities 99.3 132.3 Total other long-term liabilities $ 436.1 $ 418.3 Supplemental Cash Flow Information The following table provides supplemental non-cash investing and financing activities (in millions): Nine Months Ended September 30, 2020 2019 Equipment transfers, including operating lease assets, from inventory to property, plant, and equipment $ 123.6 $ 147.6 Deferred payments and contingent consideration related to business combinations $ 4.1 $ 130.9

REVENUE AND CONTRACT ACQUISITIO

REVENUE AND CONTRACT ACQUISITION COSTS	9 Months Ended
REVENUE AND CONTRACT ACQUISITION COSTS	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
REVENUE AND CONTRACT ACQUISITION COSTS	REVENUE AND CONTRACT ACQUISITION COSTS The following table presents revenue disaggregated by types and geography (in millions): Three Months Ended September 30, Nine Months Ended September 30, U.S. 2020 2019 2020 2019 Instruments and accessories $ 467.3 $ 450.7 $ 1,227.2 $ 1,286.7 Systems 157.7 217.2 495.8 610.5 Services 118.8 128.5 337.8 376.1 Total U.S. revenue $ 743.8 $ 796.4 $ 2,060.8 $ 2,273.3 Outside of U.S. (“OUS”) Instruments and accessories $ 163.2 $ 155.5 $ 481.6 $ 450.3 Systems 110.1 121.4 316.3 319.4 Services 60.6 54.9 170.6 157.8 Total OUS revenue $ 333.9 $ 331.8 $ 968.5 $ 927.5 Total Instruments and accessories $ 630.5 $ 606.2 $ 1,708.8 $ 1,737.0 Systems 267.8 338.6 812.1 929.9 Services 179.4 183.4 508.4 533.9 Total revenue $ 1,077.7 $ 1,128.2 $ 3,029.3 $ 3,200.8 Remaining Performance Obligations The transaction price allocated to remaining performance obligations relates to amounts allocated to products and services for which revenue has not yet been recognized. A significant portion of this amount relates to performance obligations in the Company’s service contracts that will be satisfied and recognized as revenue in future periods. In addition, non-lease elements associated with the Company's lease arrangements are primarily comprised of service contracts that will be satisfied and recognized as revenue in future periods. The transaction price allocated to the remaining performance obligations and the non-lease elements associated with lease arrangements was $1,508 million as of September 30, 2020. The remaining performance obligations are expected to be satisfied over the term of the individual sales arrangements, which generally are 5 years. Service revenue associated with the lease arrangements will generally be recognized over the service period, which generally coincides with the lease term. Contract Assets and Liabilities The following information summarizes the Company’s contract assets and liabilities (in millions): As of September 30, 2020 December 31, 2019 Contract assets $ 31.1 $ 20.8 Deferred revenue $ 358.1 $ 365.2 The Company invoices its customers based on the billing schedules in its sales arrangements. Payments are generally due 30 days from date of invoice. Contract assets for the periods presented primarily represent the difference between the revenue that was recognized based on the relative standalone selling price of the related performance obligations satisfied and the contractual billing terms in the arrangements. Deferred revenue for the periods presented primarily relates to service contracts where the service fees are billed up-front, generally quarterly or annually, prior to those services having been performed. The associated deferred revenue is generally recognized over the term of the service period. The Company did not have any significant impairment losses on its contract assets for the periods presented. During the three and nine months ended September 30, 2020, the Company recognized $58.1 million and $249.7 million , respectively, of revenue, net of the impact of the Customer Relief Program, that was included in the deferred revenue balance as of December 31, 2019. During the three and nine months ended September 30, 2019, the Company recognized $57.7 million and $281.4 million, respectively, of revenue that was included in the deferred revenue balance as of December 31, 2018. Intuitive System Leasing The following table presents revenue from Intuitive System Leasing arrangements (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Sales-type lease revenue $ 24.7 $ 14.8 $ 96.5 $ 34.7 Operating lease revenue $ 45.7 $ 27.4 $ 127.0 $ 72.9 Assets Recognized from the Costs to Obtain a Contract with a Customer The Company has determined that certain sales incentives provided to the Company’s sales team are required to be capitalized when the Company expects to generate future economic benefits from the related revenue-generating contracts subsequent to the initial capital sales transaction. When determining the economic life of the contract acquisition assets recognized, the Company considers historical service renewal rates, expectations of future customer renewals of service contracts, and other factors that could impact the economic benefits that the Company expects to generate from the relationship with its customers. The costs capitalized as contract acquisition costs included in intangible and other assets, net in the Condensed Consolidated Balance Sheets were $48.5 million and $51.5 million as of September 30, 2020, and December 31, 2019, respectively. The Company did not incur any impairment losses during the periods presented.

LEASES

LEASES	9 Months Ended
LEASES	Sep. 30, 2020
Leases [Abstract]
LEASES	LEASES Lessor Information Sales-type Leases. Lease receivables relating to sales-type lease arrangements are presented on the Condensed Consolidated Balance Sheets as follows (in millions): As of September 30, 2020 December 31, 2019 Gross lease receivables $ 241.0 $ 191.9 Unearned income (10.7) (10.1) Subtotal 230.3 181.8 Allowance for credit loss (5.4) (1.2) Net investment in sales-type leases $ 224.9 $ 180.6 Reported as: Prepaids and other current assets $ 68.7 $ 63.1 Intangible and other assets, net 156.2 117.5 Total, net $ 224.9 $ 180.6 Contractual maturities of gross lease receivables at September 30, 2020, are as follows (in millions): Fiscal Year Amount Remainder of 2020 $ 15.4 2021 72.2 2022 57.9 2023 42.4 2024 34.5 2025 and thereafter 18.6 Total $ 241.0

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	9 Months Ended
GOODWILL AND INTANGIBLE ASSETS	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Acquisitions in 2020 Orpheus Medical In February 2020, the Company acquired Orpheus Medical Ltd. and its wholly-owned subsidiaries (“Orpheus Medical”) to deepen and expand our integrated informatics platform (the “Orpheus Medical Acquisition”). Orpheus Medical provides hospitals with information technology connectivity, as well as expertise in processing and archiving surgical videos. Acquisitions in 2019 Chindex During the first quarter of 2019, the Company’s majority-owned Joint Venture with Fosun Pharma acquired certain assets from Chindex and its affiliates, a subsidiary of Fosun Pharma, including distribution rights, customer relationships, and certain personnel on January 5, 2019, which collectively met the definition of a business. Chindex was the Company’s distributor of da Vinci products and services in China. The transaction enhances the Company’s ability to serve patients, surgeons, and hospitals in China. The total purchase consideration of $66.0 million, as of the acquisition date, included a contingent consideration liability of $64.7 million and an upfront cash payment of $1.3 million. The amount and timing of the future contingent consideration payments are based upon the underlying performance of the business in 2019 and 2020. As of the acquisition date, the estimated total undiscounted contingent consideration was approximately $81 million. The undiscounted contingent consideration has decreased by approximately $2 million as of September 30, 2020, due to a change in the timing of the projected future revenues. The contingent consideration liability is measured at estimated fair value using a discounted cash flow model, which requires significant inputs not observable in the market and, thus, represents a Level 3 measurement. Key assumptions include (1) the probability and timing of milestone achievements based on revenues in 2019 and 2020 and projected future revenues in 2020, and (2) the discount rate used to calculate the present value of the milestone payments. On each reporting period until the contingent consideration is settled, the Company will re-measure the contingent consideration liability and record changes in fair value within selling, general and administrative expenses. For the nine months ended September 30, 2020, the contingent consideration liability changed due to payments of $42.0 million and net additional expense of $7.6 million. For the nine months ended September 30, 2019, the contingent consideration liability changed due to payments of $8.5 million and net additional expense of $4.1 million. Changes to the contingent consideration liability can result from adjustments to discount rates, accretion due to the passage of time, or changes in estimates in the performance of the business. The assumptions related to determining the fair value of contingent consideration include a significant amount of judgment, and any changes in the underlying estimates could have a material impact on the amount of contingent consideration adjustment recorded in any given period. Schölly During the third quarter of 2019, the Company acquired certain assets and operations from Schölly Fiberoptic GmbH (“Schölly”), including manufacturing process technology, a non-compete agreement, certain personnel, and net tangible assets on August 31, 2019, which collectively met the definition of a business. The Company believes that the transaction strengthens the Company’s supply chain and manufacturing capacity for imaging products used in the Company's da Vinci systems. The total purchase consideration of $101.4 million consisted of an initial cash payment of $34.4 million and deferred cash payments totaling approximately $67.0 million, of which $34.6 million continues to be deferred as of September 30, 2020. The timing of future payments is based upon achieving certain integration steps, which occur during 2020 and 2021 and are expected to be completed in 2021. The Company recorded $11.5 million of net tangible assets, which included $6.7 million of inventory and $1.4 million of cash, $31.0 million of intangible assets, and $58.9 million of residual goodwill. Intangible assets included manufacturing process technology of $28.0 million and non-compete provisions of $3.0 million, which are being amortized over a weighted average period of 6.6 years. The allocation of purchase consideration was completed in the third quarter of 2020. The adjustments to the provisional amounts in the measurement period were not material. Goodwill primarily consists of the manufacturing and other synergies of the combined operations and the value of the assembled workforce. The majority of goodwill is not deductible for income tax purposes. The Company has included the results of the acquired businesses, since their acquisition dates, in its Financial Statements, and the revenues and earnings have not been material to date. Pro forma results of operations related to the acquisitions have not been presented, because the operating results of the acquired businesses are not considered material to the Financial Statements. Goodwill The following table summarizes the changes in the carrying amount of goodwill (in millions): Amount Balance at December 31, 2019 $ 307.2 Acquisition activity 29.3 Translation and other (0.2) Balance at September 30, 2020 $ 336.3 Intangible Assets The following table summarizes the components of gross intangible assets, accumulated amortization, and net intangible asset balances as of September 30, 2020 and December 31, 2019 (in millions): September 30, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Patents and developed technology $ 198.4 $ (156.2) $ 42.2 $ 186.7 $ (149.0) $ 37.7 Distribution rights and others 91.9 (69.5) 22.4 91.3 (44.9) 46.4 Customer relationships 59.0 (34.7) 24.3 57.7 (29.7) 28.0 Total intangible assets $ 349.3 $ (260.4) $ 88.9 $ 335.7 $ (223.6) $ 112.1 Amortization expense related to intangible assets was $12.6 million and $10.7 million for the three months ended September 30, 2020, and 2019, respectively. Amortization expense related to intangible assets was $37.3 million and $31.2 million for the nine months ended September 30, 2020, and 2019, respectively. The estimated future amortization expense related to intangible assets as of September 30, 2020, is as follows (in millions): Fiscal Year Amount Remainder of 2020 $ 12.2 2021 21.3 2022 18.1 2023 13.4 2024 11.4 2025 and thereafter 12.5 Total $ 88.9 The preceding expected amortization expense is an estimate. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, measurement-period adjustments to intangible assets, changes in foreign currency exchange rates, impairments of intangible assets, accelerated amortization of intangible assets, and other events.

CONTINGENCIES

CONTINGENCIES	9 Months Ended
CONTINGENCIES	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES From time to time, the Company is involved in a variety of claims, lawsuits, investigations, and proceedings relating to securities laws, product liability, intellectual property, insurance, contract disputes, employment, and other matters. Certain of these lawsuits and claims are described in further detail below. It is not possible to predict what the outcome of these matters will be, and the Company cannot guarantee that any resolution will be reached on commercially reasonable terms, if at all. A liability and related charge to earnings are recorded in the Financial Statements for legal contingencies when the loss is considered probable and the amount can be reasonably estimated. The assessment is re-evaluated each accounting period and is based on all available information, including the impact of negotiations, settlements, rulings, advice of legal counsel, and other information and events pertaining to each case. Nevertheless, it is possible that additional future legal costs (including settlements, judgments, legal fees, and other related defense costs) could have a material adverse effect on the Company’s business, financial position, and future results of operations. Product Liability Litigation The Company is currently named as a defendant in a number of individual product liability lawsuits filed in various state and federal courts. The plaintiffs generally allege that they or a family member underwent surgical procedures that utilized the da Vinci Surgical System and sustained a variety of personal injuries and, in some cases, death as a result of such surgery. Several of the filed cases have trial dates in the next 12 months. The cases raise a variety of allegations including, to varying degrees, that plaintiffs’ injuries resulted from purported defects in the da Vinci Surgical System and/or failure on the Company’s part to provide adequate training resources to the healthcare professionals who performed plaintiffs’ surgeries. The cases further allege that the Company failed to adequately disclose and/or misrepresented the potential risks and/or benefits of the da Vinci Surgical System. Plaintiffs also assert a variety of causes of action, including, for example, strict liability based on purported design defects, negligence, fraud, breach of express and implied warranties, unjust enrichment, and loss of consortium. Plaintiffs seek recovery for alleged personal injuries and, in many cases, punitive damages. The Company disputes these allegations and is defending against these claims. The Company’s estimate of the anticipated cost of resolving the pending cases is based on negotiations with attorneys for the claimants. The final outcome of the pending lawsuits and claims, and others that might arise, is dependent on many variables that are difficult to predict, and the ultimate cost associated with these product liability lawsuits and claims may be materially different than the amount of the current estimate and accruals and could have a material adverse effect on the Company’s business, financial position, and future results of operations. Although there is a reasonable possibility that a loss in excess of the amount recognized exists, the Company is unable to estimate the possible loss or range of loss in excess of the amount recognized at this time. Patent Litigation On June 30, 2017, Ethicon LLC, Ethicon Endo-Surgery, Inc., and Ethicon US LLC (collectively, “Ethicon”) filed a complaint for patent infringement against the Company in the U.S. District Court for the District of Delaware. The complaint, which was served on the Company on July 12, 2017, alleges that the Company’s EndoWrist Stapler instruments infringe several of Ethicon’s patents. Ethicon asserts infringement of U.S. Patent Nos. 9,585,658, 8,479,969, 9,113,874, 8,998,058, 8,991,677, 9,084,601, and 8,616,431. A claim construction hearing occurred on October 1, 2018, and the court issued a scheduling order on December 28, 2018. On March 20, 2019, the court granted the Company’s Motion to Stay pending an Inter Partes Review to be held at the Patent Trademark and Appeals Board to review patentability of six of the seven patents noted above and vacated the trial date. On August 1, 2019, the court granted the parties' joint stipulation to modify the stay in light of Ethicon's U.S. International Trade Commission (“USITC”) complaint against Intuitive involving U.S. Patent Nos. 8,479,969 and 9,113,874, discussed below. On August 27, 2018, Ethicon filed a second complaint for patent infringement against the Company in the U.S. District Court for the District of Delaware. The complaint alleges that the Company’s SureForm 60 Staplers infringe five of Ethicon’s patents. Ethicon asserts infringement of U.S. Patent Nos. 9,884,369, 7,490,749, 8,602,288, 8,602,287, and 9,326,770. The Company filed an answer denying all claims. On March 19, 2019, Ethicon filed a Motion for Leave to File a First Amended Complaint, removing allegations related to U.S. Patent No. 9,326,770 and adding allegations related to U.S. Patent Nos. 9,844,379 and 8,479,969. On July 17, 2019, the court entered an order denying the amendment, without prejudice, and granting the parties’ joint stipulation to stay the case in its entirety in light of the USITC investigation involving U.S. Patent Nos. 9,844,369 and 7,490,749, discussed below. On May 30, 2019, Ethicon filed a complaint with the USITC, asserting infringement of U.S. Patent Nos. 9,884,369, 7,490,749, 9,844,379, 9,113,874, and 8,479,969. On June 28, 2019, the USITC voted to institute an investigation (No. 337-TA-1167) with respect to the claims in this complaint. The accused products include the Company's EndoWrist 30, EndoWrist 45, SureForm 45, and SureForm 60 Staplers, as well as the stapler reload cartridges. In March 2020, Ethicon dismissed its claims concerning U.S. Patent No. 7,490,749. The evidentiary hearing has been set for February 8, 2021. An unfavorable ruling by the USITC could have an adverse effect on our results of operations, including a prohibition on importing the accused products into the U.S. or necessitating workarounds that may limit certain features of our products. Based on currently available information, the Company is unable to make a reasonable estimate of loss or range of losses, if any, arising from these matters. Commercial Litigation On February 27, 2019, Restore Robotics LLC and Restore Repair LLC (“Restore”) filed a complaint alleging anti-trust claims against the Company. On May 13, 2019, Restore filed an amended complaint alleging anti-trust claims relating to the da Vinci Surgical System and EndoWrist service, maintenance, and repair processes. On September 16, 2019, the Court partially granted and partially denied the Company's Motion to Dismiss the amended complaint. On September 30, 2019, the Company filed an answer denying the anti-trust allegations and a counterclaim against Restore. The Company filed amended counterclaims after the Court partially granted and partially denied Restore's Motion to Dismiss the counterclaim. The amended counterclaims allege that Restore violated the Federal Lanham Act, the Federal Computer Fraud and Abuse Act, and Florida's Deceptive and Unfair Trade Practices Act and that Restore is also liable to the Company for Unfair Competition and Tortious Interference with Contract. On January 7, 2020, the Court denied Restore's Motion to Dismiss the amended counterclaims. In its initial scheduling order, the Court stated that it anticipated trial in this case to occur in or before February 2022. Based on currently available information, the Company is unable to make a reasonable estimate of loss or range of losses, if any, arising from these matters. On September 28, 2020, Rebotix Repair Inc. (“Rebotix”) filed a complaint alleging anti-trust claims against the Company relating to EndoWrist service, maintenance, and repair processes. The complaint was formally served on the Company on October 6, 2020. Based on currently available information, the Company is unable to make a reasonable estimate of loss or range of losses, if any, arising from this matter.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	9 Months Ended
STOCKHOLDERS' EQUITY	Sep. 30, 2020
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Stockholders’ Equity The following tables present the changes in stockholders’ equity (in millions): Three Months Ended September 30, 2020 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 117.0 $ 0.1 $ 6,085.1 $ 2,633.0 $ 22.3 $ 8,740.5 $ 25.9 $ 8,766.4 Issuance of common stock through employee stock plans 0.5 — 113.9 113.9 113.9 Shares withheld related to net share settlement of equity awards — — (0.5) (9.7) (10.2) (10.2) Share-based compensation expense related to employee stock plans 105.8 105.8 105.8 Net income attributable to Intuitive Surgical, Inc. 313.9 313.9 313.9 Other comprehensive income (loss) (6.1) (6.1) 0.1 (6.0) Net income attributable to noncontrolling interest in joint venture — 2.9 2.9 Ending balance 117.5 $ 0.1 $ 6,304.3 $ 2,937.2 $ 16.2 $ 9,257.8 $ 28.9 $ 9,286.7 Three Months Ended September 30, 2019 Common Stock Additional Retained Accumulated Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 115.2 $ 0.1 $ 5,430.1 $ 1,819.0 $ 16.1 $ 7,265.3 $ 14.3 $ 7,279.6 Issuance of common stock through employee stock plans 0.6 — 86.1 86.1 86.1 Shares withheld related to net share settlement of equity awards — — (0.5) (7.4) (7.9) (7.9) Share-based compensation expense related to employee stock plans 88.9 88.9 88.9 Repurchase and retirement of common stock (0.2) — (3.7) (65.8) (69.5) (69.5) Net income attributable to Intuitive Surgical, Inc. 396.8 396.8 396.8 Other comprehensive income 1.7 1.7 (0.5) 1.2 Net income attributable to noncontrolling interest in joint venture — 1.9 1.9 Ending balance 115.6 $ 0.1 $ 5,600.9 $ 2,142.6 $ 17.8 $ 7,761.4 $ 15.7 $ 7,777.1 Nine Months Ended September 30, 2020 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 116.0 $ 0.1 $ 5,756.8 $ 2,494.5 $ 12.4 $ 8,263.8 $ 20.9 $ 8,284.7 Adoption of new accounting standard (0.1) (0.1) (0.1) Issuance of common stock through employee stock plans 2.0 — 267.9 267.9 267.9 Shares withheld related to net share settlement of equity awards (0.3) — (7.5) (157.8) (165.3) (165.3) Share-based compensation expense related to employee stock plans 292.3 292.3 292.3 Repurchase and retirement of common stock (0.2) — (5.2) (94.8) (100.0) (100.0) Net income attributable to Intuitive Surgical, Inc. 695.4 695.4 695.4 Other comprehensive income 3.8 3.8 0.2 4.0 Net income attributable to noncontrolling interest in joint venture — 7.8 7.8 Ending balance 117.5 $ 0.1 $ 6,304.3 $ 2,937.2 $ 16.2 $ 9,257.8 $ 28.9 $ 9,286.7 Nine Months Ended September 30, 2019 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 114.5 $ 0.1 $ 5,170.3 $ 1,521.7 $ (13.3) $ 6,678.8 $ 8.7 $ 6,687.5 Issuance of common stock through employee stock plans 2.0 — 205.7 205.7 205.7 Shares withheld related to net share settlement of equity awards (0.3) — (7.2) (145.7) (152.9) (152.9) Share-based compensation expense related to employee stock plans 246.6 246.6 246.6 Repurchase and retirement of common stock (0.6) — (14.5) (255.0) (269.5) (269.5) Net income attributable to Intuitive Surgical, Inc. 1021.6 1021.6 1021.6 Other comprehensive income 31.1 31.1 (0.5) 30.6 Capital contribution from noncontrolling interest — 10.0 10.0 Net loss attributable to noncontrolling interest in joint venture — (2.5) (2.5) Ending balance 115.6 $ 0.1 $ 5,600.9 $ 2,142.6 $ 17.8 $ 7,761.4 $ 15.7 $ 7,777.1 Stock Repurchase Program The Company’s Board of Directors (the “Board”) has authorized an aggregate of $7.5 billion of funding for the Company’s common stock repurchase program (the “Repurchase Program”) since its establishment in March 2009. The most recent authorization occurred in January 2019 when the Board increased the authorized amount available under the Repurchase Program to $2.0 billion. As of September 30, 2020, the remaining amount of share repurchases authorized by the Board was $1.6 billion. The following table provides share repurchase activities (in millions, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Shares repurchased — 0.2 0.2 0.6 Average price per share $ — $ 492.94 $ 521.83 $ 481.35 Value of shares repurchased $ — $ 69.5 $ 100.0 $ 269.5 Accumulated Other Comprehensive Income (Loss), Net of Tax, Attributable to Intuitive The components of accumulated other comprehensive income (loss), net of tax, attributable to Intuitive are as follows (in millions): Three Months Ended September 30, 2020 Gains (Losses) Unrealized Gains Foreign Employee Benefit Plans Total Beginning balance $ 0.4 $ 44.1 $ (13.8) $ (8.4) $ 22.3 Other comprehensive income (loss) before reclassifications (0.8) (7.1) 2.2 — (5.7) Amounts reclassified from accumulated other comprehensive income (loss) (0.6) — — 0.2 (0.4) Net current-period other comprehensive income (loss) (1.4) (7.1) 2.2 0.2 (6.1) Ending balance $ (1.0) $ 37.0 $ (11.6) $ (8.2) $ 16.2 Three Months Ended September 30, 2019 Gains (Losses) Unrealized Gains Foreign Employee Benefit Plans Total Beginning balance $ 0.5 $ 19.7 $ (0.8) $ (3.3) $ 16.1 Other comprehensive income (loss) before reclassifications 4.1 1.7 (3.0) — 2.8 Amounts reclassified from accumulated other comprehensive income (loss) (1.0) (0.2) — 0.1 (1.1) Net current-period other comprehensive income (loss) 3.1 1.5 (3.0) 0.1 1.7 Ending balance $ 3.6 $ 21.2 $ (3.8) $ (3.2) $ 17.8 Nine Months Ended September 30, 2020 Gains (Losses) on Hedge Instruments Unrealized Gains Foreign Currency Translation Gains (Losses) Employee Benefit Plans Total Beginning balance $ 0.7 $ 20.4 $ — $ (8.7) $ 12.4 Other comprehensive income (loss) before reclassifications 2.0 21.3 (11.6) — 11.7 Amounts reclassified from accumulated other comprehensive income (loss) (3.7) (4.7) — 0.5 (7.9) Net current-period other comprehensive income (loss) (1.7) 16.6 (11.6) 0.5 3.8 Ending balance $ (1.0) $ 37.0 $ (11.6) $ (8.2) $ 16.2 Nine Months Ended September 30, 2019 Gains (Losses) on Hedge Instruments Unrealized Gains Foreign Currency Translation Gains (Losses) Employee Benefit Plans Total Beginning balance $ 0.2 $ (9.8) $ (0.3) $ (3.4) $ (13.3) Other comprehensive income (loss) before reclassifications 7.4 31.3 (3.5) (0.1) 35.1 Amounts reclassified from accumulated other comprehensive income (loss) (4.0) (0.3) — 0.3 (4.0) Net current-period other comprehensive income (loss) 3.4 31.0 (3.5) 0.2 31.1 Ending balance $ 3.6 $ 21.2 $ (3.8) $ (3.2) $ 17.8

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	9 Months Ended
SHARE-BASED COMPENSATION	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION In April 2020, the Company's shareholders approved an amended and restated 2010 Incentive Award Plan to provide for an increase in the number of shares of common stock reserved for issuance thereunder from 28,450,000 to 32,450,000. As of September 30, 2020, approximately 8.2 million shares were reserved for future issuance under the Company's stock plans. A maximum of approximately 3.6 million of these shares can be awarded as restricted stock units (“RSUs”). Stock Option Information A summary of stock option activity under all stock plans for the nine months ended September 30, 2020, is presented as follows (in millions, except per share amounts): Stock Options Outstanding Number Weighted Average Balance at December 31, 2019 5.4 $ 246.64 Options granted 0.5 $ 619.59 Options exercised (1.1) $ 174.40 Options forfeited/expired (0.1) $ 478.67 Balance at September 30, 2020 4.7 $ 299.92 As of September 30, 2020, options to purchase an aggregate of 3.6 million shares of common stock were exercisable at a weighted average price of $230.78 per share. Restricted Stock Units Information A summary of RSUs activity under all stock plans for the nine months ended September 30, 2020, is presented as follows (in millions, except per share amounts): Shares Weighted Average Unvested balance at December 31, 2019 1.9 $ 410.09 RSUs granted 0.7 $ 540.05 RSUs vested (0.7) $ 341.41 RSUs forfeited (0.1) $ 463.48 Unvested balance at September 30, 2020 1.8 $ 486.08 Employee Stock Purchase Plan Under the Employee Stock Purchase Plan (“ESPP”), employees purchased approximately 0.2 million shares for $71.2 million and approximately 0.2 million shares for $56.4 million during the nine months ended September 30, 2020, and 2019, respectively. Share-based Compensation Expense The following table summarizes share-based compensation expense for the three and nine months ended September 30, 2020, and 2019 (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of sales – products $ 16.2 $ 12.4 $ 43.0 $ 34.8 Cost of sales – services 7.1 5.6 17.8 14.9 Total cost of sales 23.3 18.0 60.8 49.7 Selling, general, and administrative 54.2 44.7 149.5 124.0 Research and development 29.5 26.6 84.1 74.5 Share-based compensation expense before income taxes 107.0 89.3 294.4 248.2 Income tax benefit 22.3 18.1 61.2 51.0 Share-based compensation expense after income taxes $ 84.7 $ 71.2 $ 233.2 $ 197.2 The Black-Scholes option pricing model is used to estimate the fair value of stock options granted under the Company’s share-based compensation plans and rights to acquire stock granted under the ESPP. The weighted average estimated fair values of stock options and the rights to acquire stock under the ESPP, as well as the weighted average assumptions used in calculating the fair values of stock options and the rights to acquire stock under the ESPP that were granted during the three and nine months ended September 30, 2020, and 2019, were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock Options Risk-free interest rate 0.2% 1.5% 0.6% 2.0% Expected term (in years) 3.9 3.9 4.1 4.1 Expected volatility 34% 30% 32% 30% Fair value at grant date $187.94 $127.19 $160.72 $142.22 ESPP Risk-free interest rate 0.1% 1.9% 0.9% 2.1% Expected term (in years) 1.3 1.2 1.2 1.2 Expected volatility 34% 29% 30% 29% Fair value at grant date $203.56 $146.48 $171.87 $148.99

INCOME TAXES

INCOME TAXES	9 Months Ended
INCOME TAXES	Sep. 30, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Income tax expense for the three months ended September 30, 2020, was $38.4 million, or 10.8% of income before taxes, compared to $0.3 million, or 0.1% of income before taxes, for the three months ended September 30, 2019. Income tax expense for the nine months ended September 30, 2020, was $67.3 million, or 8.7% of income before taxes, compared to $51.4 million, or 4.8% of income before taxes, for the nine months ended September 30, 2019. The effective tax rates for the three and nine months ended September 30, 2020, and 2019, differed from the U.S. federal statutory rate of 21% mainly due to excess tax benefits associated with employee equity plans, the effect of income earned by certain overseas entities being taxed at rates lower than the federal statutory rate, and the federal research and development (“R&D”) credit benefit, partially offset by state income taxes (net of federal benefit) and U.S. tax on foreign earnings. The effective tax rate for the three and nine months ended September 30, 2019, reflected a $51.3 million decrease in income tax expense as a result of the re-measurement of Swiss deferred tax assets due to a Swiss tax rate change. The effective tax rate for the nine months ended September 30, 2020, reflected a $36.8 million increase in income tax expense discussed below. In July 2015, a U.S. Tax Court opinion (the “2015 Opinion”) was issued involving an independent third party related to charging foreign subsidiaries for share-based compensation. Based on the findings of the U.S. Tax Court, direct share-based compensation has been excluded from the Company's intercompany charges starting in 2015. In June 2019, the Ninth Circuit Court of Appeals (the “Ninth Circuit”) reversed the 2015 Opinion (the “Ninth Circuit Opinion”). Subsequently, a re-hearing of the case was requested but was denied in November 2019. In February 2020, a petition was filed to appeal the Ninth Circuit Opinion to the U.S. Supreme Court. The petition was denied by the U.S. Supreme Court on June 22, 2020, which makes the Ninth Circuit Opinion binding precedent in the Ninth Circuit. As a result, the Company increased its unrecognized tax benefits by $36.8 million with a corresponding increase to income tax expense for the three months ended June 30, 2020, related to the intercompany charges for share-based compensation for relevant periods prior to 2020. The Company will continue to monitor future Internal Revenue Service ("IRS") actions or other developments regarding this matter and will assess the impact of any such developments to its income tax provision in the quarter that they occur. The Company is treating share-based compensation expense in accordance with the Ninth Circuit Opinion for 2020 and going forward. The Company files federal, state, and foreign income tax returns in many U.S. and OUS jurisdictions. Years before 2016 are closed for the significant jurisdictions. Certain of the Company’s unrecognized tax benefits could change due to activities of various tax authorities, including evolving interpretations of existing tax laws in the jurisdictions the Company operates, potential assessment of additional tax, possible settlement of audits, or through normal expiration of various statutes of limitations, which could affect the Company’s effective tax rate in the period in which they change. Due to the uncertainty related to the timing and potential outcome of audits, the Company cannot estimate the range of reasonably possible change in unrecognized tax benefits that may occur in the next 12 months. The Company is subject to the examination of its income tax returns by the IRS and other tax authorities. The outcome of these audits cannot be predicted with certainty. The Company’s management regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of the Company’s provision for income taxes. If any issues addressed in the Company’s tax audits are resolved in a manner not consistent with management’s expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs.

NET INCOME PER SHARE

NET INCOME PER SHARE	9 Months Ended
NET INCOME PER SHARE	Sep. 30, 2020
Earnings Per Share [Abstract]
NET INCOME PER SHARE	NET INCOME PER SHARE The following table presents the computation of basic and diluted net income per share attributable to Intuitive Surgical, Inc. (in millions, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net income attributable to Intuitive Surgical, Inc. $ 313.9 $ 396.8 $ 695.4 $ 1,021.6 Denominator: Weighted average shares outstanding used in basic calculation 117.3 115.4 116.8 115.3 Add: dilutive effect of potential common shares 3.3 3.9 3.2 4.1 Weighted average shares outstanding used in diluted calculation 120.6 119.3 120.0 119.4 Net income per share attributable to Intuitive Surgical, Inc.: Basic $ 2.68 $ 3.44 $ 5.95 $ 8.86 Diluted $ 2.60 $ 3.33 $ 5.80 $ 8.56 Share-based compensation awards of approximately 0.2 million and 0.8 million shares for the three months ended September 30, 2020, and 2019, respectively, and approximately 0.9 million and 0.6 million for the nine months ended September 30, 2020, and 2019, respectively, were outstanding but were not included in the computation of diluted net income per share attributable to Intuitive Surgical, Inc. common stockholders because the effect of including such shares would have been anti-dilutive in the periods presented.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Sep. 30, 2020
Accounting Policies [Abstract]
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 and majority-owned subsidiaries have been prepared on a consistent basis with the audited Consolidated Financial Statements for the fiscal year ended December 31, 2019, and include all adjustments, consisting of only normal, recurring adjustments, necessary to fairly state the information set forth herein. The 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 Financial Statements in accordance with United States (“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, 2019, which was filed with the SEC on February 7, 2020. The results of operations for the first nine months of fiscal year 2020 are not necessarily indicative of the results to be expected for the entire fiscal year or any future periods.
Consolidation and Joint Ventures	The Financial Statements include the results and the balances of the Company’s majority-owned joint venture (referred to herein as the “Joint Venture”) with Shanghai Fosun Pharmaceutical (Group) Co., Ltd. (“Fosun Pharma”). The Company holds a controlling financial interest in the Joint Venture, and the noncontrolling interest is reflected as a separate component of consolidated stockholders’ equity. The noncontrolling interest’s share of the earnings in the Joint Venture is presented separately in the condensed consolidated statements of income.
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements Credit Losses In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) (“Topic 326”), which replaces existing incurred loss impairment guidance and establishes a single allowance framework for financial assets carried at amortized cost. The Company adopted Topic 326 on January 1, 2020, using a modified retrospective transition method, which requires a cumulative-effect adjustment, if any, to the opening balance of retained earnings to be recognized on the date of adoption with prior periods not restated. The cumulative-effect adjustment recorded on January 1, 2020, was not material. Please see the description of the Company’s “Credit Losses” accounting policy in the “Significant Accounting Policies” section below. Significant Accounting Policies With the exception of the aspects within the Customer Relief Program noted above and the change for the accounting of credit losses as a result of the adoption of Topic 326, there have been no new or material changes to the significant accounting policies discussed in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019, that are of significance, or potential significance, to the Company. Credit Losses Trade accounts receivable. The allowance for doubtful accounts is based on the Company’s assessment of the collectibility of customer accounts. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the accounts receivable balances, and current economic conditions that may affect a customer’s ability to pay. For the three and nine months ended September 30, 2020, and 2019, bad debt expense was not significant. Net investment in sales-type leases. The Company enters into sales-type leases with certain qualified customers to purchase its systems. Sales-type leases have terms that generally range from 24 to 84 months and are usually collateralized by a security interest in the underlying assets. The allowance for loan loss is based on the Company's assessment of current expected lifetime loss on lease receivables. The Company regularly reviews the allowance by considering factors such as historical experience, credit quality, the age of the lease receivable balances, and current economic conditions that may affect a customer's ability to pay. Lease receivables are considered past due 90 days after invoice. The Company manages the credit risk in net investment in sales-type leases using a number of factors, including, but not limited to the following: size of operations; profitability, liquidity, and debt ratios; payment history; and past due amounts. The Company also uses credit scores obtained from external providers as a key credit quality indicator for the purposes of determining credit quality. The following table presents credit quality by class of net investment in sales-type lease as of September 30, 2020. The following table summarizes the amortized cost basis by year of origination and credit quality indicator as of September 30, 2020 (in millions): 2020 2019 2018 2017 2016 Prior Net Investment Credit Rating: High $ 43.1 $ 37.0 $ 14.6 $ 7.9 $ 2.4 $ 1.4 $ 106.4 Moderate 48.4 34.8 21.6 6.8 2.9 0.4 114.9 Low 6.6 1.0 0.4 — 1.0 — 9.0 Total $ 98.1 $ 72.8 $ 36.6 $ 14.7 $ 6.3 $ 1.8 $ 230.3 For the three and nine months ended September 30, 2020, and 2019, credit losses related to net investment in sales-type leases were not significant. Available-for-sale debt securities. The Company's investment portfolio at any point in time contains investments in U.S. treasury and U.S. government agency securities, taxable and tax-exempt municipal notes, corporate notes and bonds, commercial paper, non-U.S. government agency securities, cash deposits, and money market funds. The Company segments its portfolio based on the underlying risk profiles of the securities and have a zero loss expectation for U.S. treasury and U.S. government agency securities. The Company regularly reviews the securities in an unrealized loss position and evaluates the current expected credit loss by considering factors such as historical experience, market data, issuer-specific factors, and current economic conditions. For the three and nine months ended September 30, 2020, the credit losses related to available-for-sales debt securities were not significant. For both the three and nine months ended September 30, 2019, there were no credit losses recognized related to available-for-sales debt securities. The Company's exposure to credit losses may increase if its customers are adversely affected by changes in healthcare laws, coverage, and reimbursement, economic pressures or uncertainty associated with local or global economic recessions, disruption associated with the current COVID-19 pandemic, or other customer-specific factors. Although the Company has historically not experienced significant credit losses, it is possible that there could be a material adverse impact from potential adjustments of the carrying amount of lease and trade receivables as hospital cash flows are impacted by their response to the COVID-19 pandemic and deferral of elective surgical procedures.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Sep. 30, 2020
Accounting Policies [Abstract]
Amortized Cost Basis by Year of Origination and Credit Quality Indicator	The following table summarizes the amortized cost basis by year of origination and credit quality indicator as of September 30, 2020 (in millions): 2020 2019 2018 2017 2016 Prior Net Investment Credit Rating: High $ 43.1 $ 37.0 $ 14.6 $ 7.9 $ 2.4 $ 1.4 $ 106.4 Moderate 48.4 34.8 21.6 6.8 2.9 0.4 114.9 Low 6.6 1.0 0.4 — 1.0 — 9.0 Total $ 98.1 $ 72.8 $ 36.6 $ 14.7 $ 6.3 $ 1.8 $ 230.3

FINANCIAL INSTRUMENTS (Tables)

FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
FINANCIAL INSTRUMENTS (Tables)	Sep. 30, 2020
Investments, All Other Investments [Abstract]
Summary of Cash and Available-For-Sale Securities	The following tables summarize the Company’s cash and available-for-sale marketable securities’ amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category reported as cash and cash equivalents, short-term investments, or long-term investments as of September 30, 2020, and December 31, 2019 (in millions): Reported as: Amortized Gross Gross Allowance for Credit Loss Fair Cash and Short- Long- September 30, 2020 Cash $ 508.7 $ — $ — $ — $ 508.7 $ 508.7 $ — $ — Level 1: Money market funds 745.5 — — — 745.5 745.5 — — U.S. treasuries 2,337.5 28.9 — — 2,366.4 108.5 1,405.2 852.7 Subtotal 3,083.0 28.9 — — 3,111.9 854.0 1,405.2 852.7 Level 2: Commercial paper 554.1 — — — 554.1 5.0 549.1 — Corporate debt securities 1,514.8 15.1 (0.2) — 1,529.7 2.9 1,135.0 391.8 U.S. government agencies 550.2 3.0 — — 553.2 — 228.0 325.2 Non-U.S. government securities 9.5 — — — 9.5 — 4.5 5.0 Municipal securities 92.1 2.2 — — 94.3 — 25.8 68.5 Subtotal 2,720.7 20.3 (0.2) — 2,740.8 7.9 1,942.4 790.5 Total assets measured at fair value $ 6,312.4 $ 49.2 $ (0.2) $ — $ 6,361.4 $ 1,370.6 $ 3,347.6 $ 1,643.2 Reported as: Amortized Gross Gross Fair Cash and Short- Long- December 31, 2019 Cash $ 413.1 $ — $ — $ 413.1 $ 413.1 $ — $ — Level 1: Money market funds 726.8 — — 726.8 726.8 — — U.S. treasuries 1,935.8 9.7 (0.4) 1,945.1 — 890.8 1,054.3 Subtotal 2,662.6 9.7 (0.4) 2,671.9 726.8 890.8 1,054.3 Level 2: Commercial paper 165.1 — — 165.1 25.5 139.6 — Corporate debt securities 2,096.1 16.8 (0.2) 2,112.7 — 798.5 1,314.2 U.S. government agencies 418.3 1.1 (0.2) 419.2 — 209.6 209.6 Non-U.S. government securities 4.5 — — 4.5 — 4.5 — Municipal securities 58.4 0.3 — 58.7 2.2 11.1 45.4 Subtotal 2,742.4 18.2 (0.4) 2,760.2 27.7 1,163.3 1,569.2 Total assets measured at fair value $ 5,818.1 $ 27.9 $ (0.8) $ 5,845.2 $ 1,167.6 $ 2,054.1 $ 2,623.5
Summary of Contractual Maturities of Cash Equivalents and Available-For-Sale Investments	The following table summarizes the contractual maturities of the Company’s cash equivalents and available-for-sale investments (excluding cash and money market funds), as of September 30, 2020 (in millions): Amortized Fair Mature in less than one year $ 3,452.0 $ 3,464.0 Mature in one to five years 1,606.2 1,643.2 Total $ 5,058.2 $ 5,107.2
Summary of Equity Investment Activity	The following table is a summary of the activity related to equity investments (in millions): Reported as: December 31, 2019 Changes in Fair Value (1) Sales/Purchases/Others (2) September 30, 2020 Carrying Value Prepaids and other current assets Intangible and other assets, net Equity investments with readily determinable value (Level 1) $ — $ 6.1 $ 59.8 $ 65.9 $ 65.9 $ — Equity investments without readily determinable value (Level 2) $ 24.6 $ 61.5 $ (58.2) $ 27.9 $ — $ 27.9 (1) Recorded in Interest and other income, net. (2) Other includes conversion of certain equity investments without readily determinable value to equity investments with readily determinable value.
Derivatives Not Designated as Hedging Instruments	These derivative instruments are used to hedge against balance sheet foreign currency exposures. The related gains and losses were as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Recognized gains/(losses) in interest and other income, net $ (5.0) $ 4.2 $ (3.2) $ 5.7 Foreign exchange gains/(losses) related to balance sheet re-measurement $ 5.9 $ (3.8) $ (1.1) $ (3.5)
Gross Notional Amounts for Derivatives and Aggregate Gross Fair Value Outstanding	The notional amounts for derivative instruments provide one measure of the transaction volume. Total gross notional amounts (in USD) for outstanding derivatives and the aggregate gross fair value at the end of each period were as follows (in millions): Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments September 30, December 31, 2019 September 30, December 31, 2019 Notional amounts: Forward contracts $ 144.0 $ 154.5 $ 260.9 $ 227.2 Gross fair value recorded in: Prepaids and other current assets $ 0.9 $ 1.3 $ 0.9 $ 2.2 Other accrued liabilities $ 1.8 $ 0.5 $ 1.3 $ 0.7

BALANCE SHEET DETAILS AND OTH_2

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventory Details	The following tables provide details of selected balance sheet line items (in millions): As of Inventory September 30, December 31, Raw materials $ 197.1 $ 211.0 Work-in-process 66.5 75.9 Finished goods 399.3 308.6 Total inventory $ 662.9 $ 595.5
Prepaids and Other Current Assets	As of Prepaids and other current assets September 30, December 31, Prepaid taxes $ 103.3 $ 28.0 Equity investments 65.9 — Net investment in sales-type leases – short-term 68.7 63.1 Other prepaids and other current assets 92.7 109.1 Total prepaids and other current assets $ 330.6 $ 200.2
Other Accrued Liabilities - Short-term	As of Other accrued liabilities–short-term September 30, December 31, Taxes payable $ 35.3 $ 37.9 Current portion of deferred purchase consideration payments 39.0 35.7 Current portion of contingent consideration 24.8 44.5 Other accrued liabilities 176.6 199.2 Total other accrued liabilities–short-term $ 275.7 $ 317.3
Other Long-term Liabilities	As of Other long-term liabilities September 30, December 31, Income taxes–long-term $ 306.5 $ 258.6 Deferred revenue–long-term 30.3 27.4 Other long-term liabilities 99.3 132.3 Total other long-term liabilities $ 436.1 $ 418.3
Supplemental Cash Flow Information	The following table provides supplemental non-cash investing and financing activities (in millions): Nine Months Ended September 30, 2020 2019 Equipment transfers, including operating lease assets, from inventory to property, plant, and equipment $ 123.6 $ 147.6 Deferred payments and contingent consideration related to business combinations $ 4.1 $ 130.9

REVENUE AND CONTRACT ACQUISIT_2

REVENUE AND CONTRACT ACQUISITION COSTS (Tables)	9 Months Ended
REVENUE AND CONTRACT ACQUISITION COSTS (Tables)	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue Disaggregated by Types and Geography	The following table presents revenue disaggregated by types and geography (in millions): Three Months Ended September 30, Nine Months Ended September 30, U.S. 2020 2019 2020 2019 Instruments and accessories $ 467.3 $ 450.7 $ 1,227.2 $ 1,286.7 Systems 157.7 217.2 495.8 610.5 Services 118.8 128.5 337.8 376.1 Total U.S. revenue $ 743.8 $ 796.4 $ 2,060.8 $ 2,273.3 Outside of U.S. (“OUS”) Instruments and accessories $ 163.2 $ 155.5 $ 481.6 $ 450.3 Systems 110.1 121.4 316.3 319.4 Services 60.6 54.9 170.6 157.8 Total OUS revenue $ 333.9 $ 331.8 $ 968.5 $ 927.5 Total Instruments and accessories $ 630.5 $ 606.2 $ 1,708.8 $ 1,737.0 Systems 267.8 338.6 812.1 929.9 Services 179.4 183.4 508.4 533.9 Total revenue $ 1,077.7 $ 1,128.2 $ 3,029.3 $ 3,200.8
Summary of Contract Assets and Liabilities	The following information summarizes the Company’s contract assets and liabilities (in millions): As of September 30, 2020 December 31, 2019 Contract assets $ 31.1 $ 20.8 Deferred revenue $ 358.1 $ 365.2
Sales-type Lease Revenue	The following table presents revenue from Intuitive System Leasing arrangements (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Sales-type lease revenue $ 24.7 $ 14.8 $ 96.5 $ 34.7 Operating lease revenue $ 45.7 $ 27.4 $ 127.0 $ 72.9
Operating Lease Revenue	The following table presents revenue from Intuitive System Leasing arrangements (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Sales-type lease revenue $ 24.7 $ 14.8 $ 96.5 $ 34.7 Operating lease revenue $ 45.7 $ 27.4 $ 127.0 $ 72.9

LEASES (Tables)

LEASES (Tables)	9 Months Ended
LEASES (Tables)	Sep. 30, 2020
Leases [Abstract]
Schedule of Lease Receivables	Lease receivables relating to sales-type lease arrangements are presented on the Condensed Consolidated Balance Sheets as follows (in millions): As of September 30, 2020 December 31, 2019 Gross lease receivables $ 241.0 $ 191.9 Unearned income (10.7) (10.1) Subtotal 230.3 181.8 Allowance for credit loss (5.4) (1.2) Net investment in sales-type leases $ 224.9 $ 180.6 Reported as: Prepaids and other current assets $ 68.7 $ 63.1 Intangible and other assets, net 156.2 117.5 Total, net $ 224.9 $ 180.6
Schedule of Lease Receivables	Sales-type Leases. Lease receivables relating to sales-type lease arrangements are presented on the Condensed Consolidated Balance Sheets as follows (in millions): As of September 30, 2020 December 31, 2019 Gross lease receivables $ 241.0 $ 191.9 Unearned income (10.7) (10.1) Subtotal 230.3 181.8 Allowance for credit loss (5.4) (1.2) Net investment in sales-type leases $ 224.9 $ 180.6 Reported as: Prepaids and other current assets $ 68.7 $ 63.1 Intangible and other assets, net 156.2 117.5 Total, net $ 224.9 $ 180.6
Schedule of Contractual Maturities of Gross Lease Receivables	Contractual maturities of gross lease receivables at September 30, 2020, are as follows (in millions): Fiscal Year Amount Remainder of 2020 $ 15.4 2021 72.2 2022 57.9 2023 42.4 2024 34.5 2025 and thereafter 18.6 Total $ 241.0

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	9 Months Ended
GOODWILL AND INTANGIBLE ASSETS (Tables)	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Summary of Changes in Goodwill	The following table summarizes the changes in the carrying amount of goodwill (in millions): Amount Balance at December 31, 2019 $ 307.2 Acquisition activity 29.3 Translation and other (0.2) Balance at September 30, 2020 $ 336.3
Schedule of Intangible Assets	The following table summarizes the components of gross intangible assets, accumulated amortization, and net intangible asset balances as of September 30, 2020 and December 31, 2019 (in millions): September 30, 2020 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Patents and developed technology $ 198.4 $ (156.2) $ 42.2 $ 186.7 $ (149.0) $ 37.7 Distribution rights and others 91.9 (69.5) 22.4 91.3 (44.9) 46.4 Customer relationships 59.0 (34.7) 24.3 57.7 (29.7) 28.0 Total intangible assets $ 349.3 $ (260.4) $ 88.9 $ 335.7 $ (223.6) $ 112.1
Schedule Of Estimated Future Amortization Expense Of Intangible Assets	The estimated future amortization expense related to intangible assets as of September 30, 2020, is as follows (in millions): Fiscal Year Amount Remainder of 2020 $ 12.2 2021 21.3 2022 18.1 2023 13.4 2024 11.4 2025 and thereafter 12.5 Total $ 88.9

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	9 Months Ended
STOCKHOLDERS' EQUITY (Tables)	Sep. 30, 2020
Equity [Abstract]
Schedule of Stockholders Equity	The following tables present the changes in stockholders’ equity (in millions): Three Months Ended September 30, 2020 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 117.0 $ 0.1 $ 6,085.1 $ 2,633.0 $ 22.3 $ 8,740.5 $ 25.9 $ 8,766.4 Issuance of common stock through employee stock plans 0.5 — 113.9 113.9 113.9 Shares withheld related to net share settlement of equity awards — — (0.5) (9.7) (10.2) (10.2) Share-based compensation expense related to employee stock plans 105.8 105.8 105.8 Net income attributable to Intuitive Surgical, Inc. 313.9 313.9 313.9 Other comprehensive income (loss) (6.1) (6.1) 0.1 (6.0) Net income attributable to noncontrolling interest in joint venture — 2.9 2.9 Ending balance 117.5 $ 0.1 $ 6,304.3 $ 2,937.2 $ 16.2 $ 9,257.8 $ 28.9 $ 9,286.7 Three Months Ended September 30, 2019 Common Stock Additional Retained Accumulated Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 115.2 $ 0.1 $ 5,430.1 $ 1,819.0 $ 16.1 $ 7,265.3 $ 14.3 $ 7,279.6 Issuance of common stock through employee stock plans 0.6 — 86.1 86.1 86.1 Shares withheld related to net share settlement of equity awards — — (0.5) (7.4) (7.9) (7.9) Share-based compensation expense related to employee stock plans 88.9 88.9 88.9 Repurchase and retirement of common stock (0.2) — (3.7) (65.8) (69.5) (69.5) Net income attributable to Intuitive Surgical, Inc. 396.8 396.8 396.8 Other comprehensive income 1.7 1.7 (0.5) 1.2 Net income attributable to noncontrolling interest in joint venture — 1.9 1.9 Ending balance 115.6 $ 0.1 $ 5,600.9 $ 2,142.6 $ 17.8 $ 7,761.4 $ 15.7 $ 7,777.1 Nine Months Ended September 30, 2020 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 116.0 $ 0.1 $ 5,756.8 $ 2,494.5 $ 12.4 $ 8,263.8 $ 20.9 $ 8,284.7 Adoption of new accounting standard (0.1) (0.1) (0.1) Issuance of common stock through employee stock plans 2.0 — 267.9 267.9 267.9 Shares withheld related to net share settlement of equity awards (0.3) — (7.5) (157.8) (165.3) (165.3) Share-based compensation expense related to employee stock plans 292.3 292.3 292.3 Repurchase and retirement of common stock (0.2) — (5.2) (94.8) (100.0) (100.0) Net income attributable to Intuitive Surgical, Inc. 695.4 695.4 695.4 Other comprehensive income 3.8 3.8 0.2 4.0 Net income attributable to noncontrolling interest in joint venture — 7.8 7.8 Ending balance 117.5 $ 0.1 $ 6,304.3 $ 2,937.2 $ 16.2 $ 9,257.8 $ 28.9 $ 9,286.7 Nine Months Ended September 30, 2019 Common Stock Additional Paid-In Capital Retained Earnings Accumulated Other Comprehensive Income (Loss) Total Intuitive Surgical, Inc. Stockholders’ Equity Noncontrolling Interest in Joint Venture Total Stockholders’ Equity Shares Amount Beginning balance 114.5 $ 0.1 $ 5,170.3 $ 1,521.7 $ (13.3) $ 6,678.8 $ 8.7 $ 6,687.5 Issuance of common stock through employee stock plans 2.0 — 205.7 205.7 205.7 Shares withheld related to net share settlement of equity awards (0.3) — (7.2) (145.7) (152.9) (152.9) Share-based compensation expense related to employee stock plans 246.6 246.6 246.6 Repurchase and retirement of common stock (0.6) — (14.5) (255.0) (269.5) (269.5) Net income attributable to Intuitive Surgical, Inc. 1021.6 1021.6 1021.6 Other comprehensive income 31.1 31.1 (0.5) 30.6 Capital contribution from noncontrolling interest — 10.0 10.0 Net loss attributable to noncontrolling interest in joint venture — (2.5) (2.5) Ending balance 115.6 $ 0.1 $ 5,600.9 $ 2,142.6 $ 17.8 $ 7,761.4 $ 15.7 $ 7,777.1
Schedule of Share Repurchase Activities	The following table provides share repurchase activities (in millions, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Shares repurchased — 0.2 0.2 0.6 Average price per share $ — $ 492.94 $ 521.83 $ 481.35 Value of shares repurchased $ — $ 69.5 $ 100.0 $ 269.5
Components of Accumulated Other Comprehensive Income, Net of Tax	The components of accumulated other comprehensive income (loss), net of tax, attributable to Intuitive are as follows (in millions): Three Months Ended September 30, 2020 Gains (Losses) Unrealized Gains Foreign Employee Benefit Plans Total Beginning balance $ 0.4 $ 44.1 $ (13.8) $ (8.4) $ 22.3 Other comprehensive income (loss) before reclassifications (0.8) (7.1) 2.2 — (5.7) Amounts reclassified from accumulated other comprehensive income (loss) (0.6) — — 0.2 (0.4) Net current-period other comprehensive income (loss) (1.4) (7.1) 2.2 0.2 (6.1) Ending balance $ (1.0) $ 37.0 $ (11.6) $ (8.2) $ 16.2 Three Months Ended September 30, 2019 Gains (Losses) Unrealized Gains Foreign Employee Benefit Plans Total Beginning balance $ 0.5 $ 19.7 $ (0.8) $ (3.3) $ 16.1 Other comprehensive income (loss) before reclassifications 4.1 1.7 (3.0) — 2.8 Amounts reclassified from accumulated other comprehensive income (loss) (1.0) (0.2) — 0.1 (1.1) Net current-period other comprehensive income (loss) 3.1 1.5 (3.0) 0.1 1.7 Ending balance $ 3.6 $ 21.2 $ (3.8) $ (3.2) $ 17.8 Nine Months Ended September 30, 2020 Gains (Losses) on Hedge Instruments Unrealized Gains Foreign Currency Translation Gains (Losses) Employee Benefit Plans Total Beginning balance $ 0.7 $ 20.4 $ — $ (8.7) $ 12.4 Other comprehensive income (loss) before reclassifications 2.0 21.3 (11.6) — 11.7 Amounts reclassified from accumulated other comprehensive income (loss) (3.7) (4.7) — 0.5 (7.9) Net current-period other comprehensive income (loss) (1.7) 16.6 (11.6) 0.5 3.8 Ending balance $ (1.0) $ 37.0 $ (11.6) $ (8.2) $ 16.2 Nine Months Ended September 30, 2019 Gains (Losses) on Hedge Instruments Unrealized Gains Foreign Currency Translation Gains (Losses) Employee Benefit Plans Total Beginning balance $ 0.2 $ (9.8) $ (0.3) $ (3.4) $ (13.3) Other comprehensive income (loss) before reclassifications 7.4 31.3 (3.5) (0.1) 35.1 Amounts reclassified from accumulated other comprehensive income (loss) (4.0) (0.3) — 0.3 (4.0) Net current-period other comprehensive income (loss) 3.4 31.0 (3.5) 0.2 31.1 Ending balance $ 3.6 $ 21.2 $ (3.8) $ (3.2) $ 17.8

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	9 Months Ended
SHARE-BASED COMPENSATION (Tables)	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity Under All Stock Plans	A summary of stock option activity under all stock plans for the nine months ended September 30, 2020, is presented as follows (in millions, except per share amounts): Stock Options Outstanding Number Weighted Average Balance at December 31, 2019 5.4 $ 246.64 Options granted 0.5 $ 619.59 Options exercised (1.1) $ 174.40 Options forfeited/expired (0.1) $ 478.67 Balance at September 30, 2020 4.7 $ 299.92
Summary of RSU Activity	A summary of RSUs activity under all stock plans for the nine months ended September 30, 2020, is presented as follows (in millions, except per share amounts): Shares Weighted Average Unvested balance at December 31, 2019 1.9 $ 410.09 RSUs granted 0.7 $ 540.05 RSUs vested (0.7) $ 341.41 RSUs forfeited (0.1) $ 463.48 Unvested balance at September 30, 2020 1.8 $ 486.08
Summary of Share-Based Compensation Expense	The following table summarizes share-based compensation expense for the three and nine months ended September 30, 2020, and 2019 (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of sales – products $ 16.2 $ 12.4 $ 43.0 $ 34.8 Cost of sales – services 7.1 5.6 17.8 14.9 Total cost of sales 23.3 18.0 60.8 49.7 Selling, general, and administrative 54.2 44.7 149.5 124.0 Research and development 29.5 26.6 84.1 74.5 Share-based compensation expense before income taxes 107.0 89.3 294.4 248.2 Income tax benefit 22.3 18.1 61.2 51.0 Share-based compensation expense after income taxes $ 84.7 $ 71.2 $ 233.2 $ 197.2
Schedule of Estimated Fair Value of the Option Using Black-Scholes Option Pricing Model, Weighted Average Assumptions	The Black-Scholes option pricing model is used to estimate the fair value of stock options granted under the Company’s share-based compensation plans and rights to acquire stock granted under the ESPP. The weighted average estimated fair values of stock options and the rights to acquire stock under the ESPP, as well as the weighted average assumptions used in calculating the fair values of stock options and the rights to acquire stock under the ESPP that were granted during the three and nine months ended September 30, 2020, and 2019, were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock Options Risk-free interest rate 0.2% 1.5% 0.6% 2.0% Expected term (in years) 3.9 3.9 4.1 4.1 Expected volatility 34% 30% 32% 30% Fair value at grant date $187.94 $127.19 $160.72 $142.22 ESPP Risk-free interest rate 0.1% 1.9% 0.9% 2.1% Expected term (in years) 1.3 1.2 1.2 1.2 Expected volatility 34% 29% 30% 29% Fair value at grant date $203.56 $146.48 $171.87 $148.99

NET INCOME PER SHARE (Tables)

NET INCOME PER SHARE (Tables)	9 Months Ended
NET INCOME PER SHARE (Tables)	Sep. 30, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income Per Share	The following table presents the computation of basic and diluted net income per share attributable to Intuitive Surgical, Inc. (in millions, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net income attributable to Intuitive Surgical, Inc. $ 313.9 $ 396.8 $ 695.4 $ 1,021.6 Denominator: Weighted average shares outstanding used in basic calculation 117.3 115.4 116.8 115.3 Add: dilutive effect of potential common shares 3.3 3.9 3.2 4.1 Weighted average shares outstanding used in diluted calculation 120.6 119.3 120.0 119.4 Net income per share attributable to Intuitive Surgical, Inc.: Basic $ 2.68 $ 3.44 $ 5.95 $ 8.86 Diluted $ 2.60 $ 3.33 $ 5.80 $ 8.56

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2019
Accounting Policies [Abstract]
Service fee credits	$ 23,000,000	$ 59,000,000
Extended payment terms for lease billings	14,000,000
Extended payment terms for trade receivables	$ 181,000,000
Lessor, Lease, Description [Line Items]
Available-for-sales debt securities credit losses			$ 0	$ 0
Minimum
Lessor, Lease, Description [Line Items]
Sales-type leases terms	24 months
Maximum
Lessor, Lease, Description [Line Items]
Sales-type leases terms	84 months

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Amortized Cost Basis by Year of Origination and Credit Quality Indicator (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Sales-type Lease, Net Investment in Lease, Credit Quality Indicator [Line Items]
2020	$ 98.1
2019	72.8
2018	36.6
2017	14.7
2016	6.3
Prior	1.8
Net investment in sales-type leases	230.3	$ 181.8
High
Sales-type Lease, Net Investment in Lease, Credit Quality Indicator [Line Items]
2020	43.1
2019	37
2018	14.6
2017	7.9
2016	2.4
Prior	1.4
Net investment in sales-type leases	106.4
Moderate
Sales-type Lease, Net Investment in Lease, Credit Quality Indicator [Line Items]
2020	48.4
2019	34.8
2018	21.6
2017	6.8
2016	2.9
Prior	0.4
Net investment in sales-type leases	114.9
Low
Sales-type Lease, Net Investment in Lease, Credit Quality Indicator [Line Items]
2020	6.6
2019	1
2018	0.4
2017	0
2016	1
Prior	0
Net investment in sales-type leases	$ 9

FINANCIAL INSTRUMENTS - Summary

FINANCIAL INSTRUMENTS - Summary of Cash and Available-For-Sale Securities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	$ 1,370.6	$ 1,167.6
Total	5,058.2
Total assets measured at fair value, Amortized Cost	6,312.4	5,818.1
Gross Unrealized Gains	49.2	27.9
Gross Unrealized Losses	(0.2)	(0.8)
Allowance for Credit Loss	0
Total assets measured at fair value, Fair Value	6,361.4	5,845.2
Short- term Investments	3,347.6	2,054.1
Long- term Investments	1,643.2	2,623.5
Cash
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	508.7	413.1
Fair Value	508.7	413.1
Level 1
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	854	726.8
Total	3,083	2,662.6
Gross Unrealized Gains	28.9	9.7
Gross Unrealized Losses	0	(0.4)
Allowance for Credit Loss	0
Fair Value	3,111.9	2,671.9
Short- term Investments	1,405.2	890.8
Long- term Investments	852.7	1,054.3
Level 1 \| Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	745.5	726.8
Fair Value	745.5	726.8
Short- term Investments	0	0
Long- term Investments	0	0
Level 1 \| U.S. treasuries
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	108.5	0
Total	2,337.5	1,935.8
Gross Unrealized Gains	28.9	9.7
Gross Unrealized Losses	0	(0.4)
Allowance for Credit Loss	0
Fair Value	2,366.4	1,945.1
Short- term Investments	1,405.2	890.8
Long- term Investments	852.7	1,054.3
Level 2
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	7.9	27.7
Total	2,720.7	2,742.4
Gross Unrealized Gains	20.3	18.2
Gross Unrealized Losses	(0.2)	(0.4)
Allowance for Credit Loss	0
Fair Value	2,740.8	2,760.2
Short- term Investments	1,942.4	1,163.3
Long- term Investments	790.5	1,569.2
Level 2 \| Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	5	25.5
Total	554.1	165.1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Allowance for Credit Loss	0
Fair Value	554.1	165.1
Short- term Investments	549.1	139.6
Long- term Investments	0	0
Level 2 \| Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	2.9	0
Total	1,514.8	2,096.1
Gross Unrealized Gains	15.1	16.8
Gross Unrealized Losses	(0.2)	(0.2)
Allowance for Credit Loss	0
Fair Value	1,529.7	2,112.7
Short- term Investments	1,135	798.5
Long- term Investments	391.8	1,314.2
Level 2 \| U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	0	0
Total	550.2	418.3
Gross Unrealized Gains	3	1.1
Gross Unrealized Losses	0	(0.2)
Allowance for Credit Loss	0
Fair Value	553.2	419.2
Short- term Investments	228	209.6
Long- term Investments	325.2	209.6
Level 2 \| Non-U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	0	0
Total	9.5	4.5
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Allowance for Credit Loss	0
Fair Value	9.5	4.5
Short- term Investments	4.5	4.5
Long- term Investments	5	0
Level 2 \| Municipal securities
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents	0	2.2
Total	92.1	58.4
Gross Unrealized Gains	2.2	0.3
Gross Unrealized Losses	0	0
Allowance for Credit Loss	0
Fair Value	94.3	58.7
Short- term Investments	25.8	11.1
Long- term Investments	$ 68.5	$ 45.4

FINANCIAL INSTRUMENTS - Summa_2

FINANCIAL INSTRUMENTS - Summary of Contractual Maturities of Cash Equivalents and Available-For-Sale Investments (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Amortized Cost
Mature in less than one year	$ 3,452
Mature in one to five years	1,606.2
Total	5,058.2
Fair Value
Mature in less than one year	3,464
Mature in one to five years	1,643.2
Total	5,107.2
Realized Investment Gains (Losses)	$ 8.3

FINANCIAL INSTRUMENTS - Summa_3

FINANCIAL INSTRUMENTS - Summary of Equity Investment Activity (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments with readily determinable value beginning balance, Carrying Value	$ 0
Equity investments with readily determinable value beginning balance, Carrying Value	65.9
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments with readily determinable value beginning balance, Carrying Value	0
Changes in Fair Value	6.1
Sales/Purchases/Others	59.8
Equity investments with readily determinable value beginning balance, Carrying Value	65.9
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments without readily determinable value, Carrying Value	27.9	$ 24.6
Changes in Fair Value	61.5
Sales/Purchases/Others	(58.2)
Prepaids and other current assets \| Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments with readily determinable value beginning balance, Carrying Value	65.9
Prepaids and other current assets \| Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments without readily determinable value, Carrying Value	0
Intangible and other assets, net \| Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments with readily determinable value beginning balance, Carrying Value	0
Intangible and other assets, net \| Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Equity investments without readily determinable value, Carrying Value	$ 27.9

FINANCIAL INSTRUMENTS - Derivat

FINANCIAL INSTRUMENTS - Derivative Instruments Used to Hedge against Balance Sheet Foreign Currency Exposures (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange gains/(losses) related to balance sheet re-measurement	$ 5.9	$ (3.8)	$ (1.1)	$ (3.5)
Forward contracts \| Other income \| Derivatives Not Designated as Hedging Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recognized gains/(losses) in interest and other income, net	$ (5)	$ 4.2	$ (3.2)	$ 5.7

FINANCIAL INSTRUMENTS - Gross N

FINANCIAL INSTRUMENTS - Gross Notional Amounts for Outstanding Derivatives (Details) - Forward contracts - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives Designated as Hedging Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	$ 144	$ 154.5
Derivatives Designated as Hedging Instruments \| Prepaids and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	0.9	1.3
Derivatives Designated as Hedging Instruments \| Other accrued liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	1.8	0.5
Derivatives Not Designated as Hedging Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	260.9	227.2
Derivatives Not Designated as Hedging Instruments \| Prepaids and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	0.9	2.2
Derivatives Not Designated as Hedging Instruments \| Other accrued liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amounts of outstanding currency forward contracts	$ 1.3	$ 0.7

BALANCE SHEET DETAILS AND OTH_3

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION - Inventory (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 197.1	$ 211
Work-in-process	66.5	75.9
Finished goods	399.3	308.6
Total inventory	$ 662.9	$ 595.5

BALANCE SHEET DETAILS AND OTH_4

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION - Prepaids and Other Current Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid taxes	$ 103.3	$ 28
Equity investments	65.9	0
Net investment in sales-type leases – short-term	68.7	63.1
Other prepaids and other current assets	92.7	109.1
Prepaids and other current assets	$ 330.6	$ 200.2

BALANCE SHEET DETAILS AND OTH_5

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION - Other Accrued Liabilities - Short-term (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Taxes payable	$ 35.3	$ 37.9
Current portion of deferred purchase consideration payments	39	35.7
Business Combination, Contingent Consideration, Liability, Current	24.8	44.5
Other accrued liabilities	176.6	199.2
Total other accrued liabilities—short-term	$ 275.7	$ 317.3

BALANCE SHEET DETAILS AND OTH_6

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION - Other Long-term Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Income taxes—long-term	$ 306.5	$ 258.6
Deferred revenue—long-term	30.3	27.4
Other long-term liabilities	99.3	132.3
Total other long-term liabilities	$ 436.1	$ 418.3

BALANCE SHEET DETAILS AND OTH_7

BALANCE SHEET DETAILS AND OTHER FINANCIAL INFORMATION - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Supplemental non-cash investing activities:
Equipment transfers, including operating lease assets, from inventory to property, plant, and equipment	$ 123.6	$ 147.6
Deferred payments and contingent consideration related to business combinations	$ 4.1	$ 130.9

REVENUE AND CONTRACT ACQUISIT_3

REVENUE AND CONTRACT ACQUISITION COSTS - Revenue Disaggregated by Types and Geography (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,077.7	$ 1,128.2	$ 3,029.3	$ 3,200.8
Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	630.5	606.2	1,708.8	1,737
Systems
Disaggregation of Revenue [Line Items]
Total revenue	267.8	338.6	812.1	929.9
Services
Disaggregation of Revenue [Line Items]
Total revenue	179.4	183.4	508.4	533.9
U.S.
Disaggregation of Revenue [Line Items]
Total revenue	743.8	796.4	2,060.8	2,273.3
U.S. \| Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	467.3	450.7	1,227.2	1,286.7
U.S. \| Systems
Disaggregation of Revenue [Line Items]
Total revenue	157.7	217.2	495.8	610.5
U.S. \| Services
Disaggregation of Revenue [Line Items]
Total revenue	118.8	128.5	337.8	376.1
Outside of U.S. (“OUS”)
Disaggregation of Revenue [Line Items]
Total revenue	333.9	331.8	968.5	927.5
Outside of U.S. (“OUS”) \| Instruments and accessories
Disaggregation of Revenue [Line Items]
Total revenue	163.2	155.5	481.6	450.3
Outside of U.S. (“OUS”) \| Systems
Disaggregation of Revenue [Line Items]
Total revenue	110.1	121.4	316.3	319.4
Outside of U.S. (“OUS”) \| Services
Disaggregation of Revenue [Line Items]
Total revenue	$ 60.6	$ 54.9	$ 170.6	$ 157.8

REVENUE AND CONTRACT ACQUISIT_4

REVENUE AND CONTRACT ACQUISITION COSTS - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Price allocated to remaining performance obligations	$ 1,508		$ 1,508
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized	58.1	$ 57.7	249.7	$ 281.4
Costs capitalized as contract acquisition costs	$ 48.5		$ 48.5		$ 51.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	5 years		5 years

REVENUE AND CONTRACT ACQUISIT_5

REVENUE AND CONTRACT ACQUISITION COSTS - Summary of Contract Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets	$ 31.1	$ 20.8
Deferred revenue	$ 358.1	$ 365.2

REVENUE AND CONTRACT ACQUISIT_6

REVENUE AND CONTRACT ACQUISITION COSTS - Sales-type and Operating Lease Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Sales-type lease revenue	$ 24.7	$ 14.8	$ 96.5	$ 34.7
Operating lease revenue	$ 45.7	$ 27.4	$ 127	$ 72.9

LEASES - Lease Receivables (Det

LEASES - Lease Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Capital Leased Assets [Line Items]
Gross lease receivables	$ 241	$ 191.9
Unearned income	(10.7)	(10.1)
Net investment in sales-type leases	230.3	181.8
Allowance for credit loss	(5.4)	(1.2)
Gross lease receivables	224.9	180.6
Prepaids and other current assets
Capital Leased Assets [Line Items]
Gross lease receivables	68.7	63.1
Intangible and other assets, net
Capital Leased Assets [Line Items]
Gross lease receivables	$ 156.2	$ 117.5

LEASES - Schedule of Contractua

LEASES - Schedule of Contractual Maturities of Gross Lease Receivables (Details) $ in Millions	Sep. 30, 2020USD ($)
Leases [Abstract]
Remainder of 2020	$ 15.4
2021	72.2
2022	57.9
2023	42.4
2024	34.5
2025 and thereafter	18.6
Total	$ 241

Intangible Assets, Goodwill and

Intangible Assets, Goodwill and Other (Details) - USD ($) $ in Millions	Aug. 31, 2019	Jan. 05, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Deferred payments and contingent consideration related to business combinations					$ 4.1	$ 130.9
Goodwill			$ 336.3		336.3		$ 307.2
Amortization of intangible assets			12.6	$ 10.7	37.3	31.2
Chindex
Business Acquisition [Line Items]
Total purchase consideration		$ 66
Deferred payments and contingent consideration related to business combinations		64.7
Cash payments		1.3
Estimated total undiscounted contingent consideration		$ 81
Decrease in undiscounted expected contingent liability					(2)
Payment of contingent liability					42	8.5
Net additional expense					7.6	$ 4.1
Schölly
Business Acquisition [Line Items]
Total purchase consideration	$ 101.4
Cash payments	34.4
Deferred cash payments	67		$ 34.6		$ 34.6
Net tangible assets acquired	11.5
Inventory	6.7
Cash	1.4
Intangible assets acquired	31
Goodwill	$ 58.9
Weighted average useful life	6 years 7 months 6 days
Schölly \| Manufacturing process technology
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 28
Schölly \| Non-compete provisions
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 3

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS - Schedule of Summary of Changes in Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 307.2
Acquisition activity	29.3
Translation and other	(0.2)
Goodwill, Ending Balance	$ 336.3

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 349.3	$ 335.7
Accumulated Amortization	(260.4)	(223.6)
Net Carrying Amount	88.9	112.1
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	198.4	186.7
Accumulated Amortization	(156.2)	(149)
Net Carrying Amount	42.2	37.7
Distribution rights and others
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	91.9	91.3
Accumulated Amortization	(69.5)	(44.9)
Net Carrying Amount	22.4	46.4
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	59	57.7
Accumulated Amortization	(34.7)	(29.7)
Net Carrying Amount	$ 24.3	$ 28

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS - Schedule Of Estimated Future Amortization Expense Of Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2020	$ 12.2
2021	21.3
2022	18.1
2023	13.4
2024	11.4
2025 and thereafter	12.5
Net Carrying Amount	$ 88.9	$ 112.1

STOCKHOLDERS' EQUITY - Schedule

STOCKHOLDERS' EQUITY - Schedule of Stockholders Equity (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			116,000
Beginning balance	$ 8,766.4	$ 7,279.6	$ 8,284.7	$ 6,687.5
Issuance of common stock through employee stock plans	113.9	86.1	267.9	205.7
Shares withheld related to net share settlement of equity awards	(10.2)	(7.9)	(165.3)	(152.9)
Share-based compensation expense related to employee stock plans	105.8	88.9	292.3	246.6
Repurchase and retirement of common stock		(69.5)	(100)	(269.5)
Net income attributable to Intuitive Surgical, Inc.	313.9	396.8	695.4	1,021.6
Other comprehensive income (loss)	(6)	1.2	4	30.6
Capital contribution from noncontrolling interest			0	10
Net income attributable to noncontrolling interest in joint venture	$ 2.9	1.9	$ 7.8	(2.5)
Ending balance (in shares)	117,500		117,500
Ending balance	$ 9,286.7	$ 7,777.1	$ 9,286.7	$ 7,777.1
Adoption of new accounting standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ (0.1)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	117,000	115,200	116,000	114,500
Beginning balance	$ 0.1	$ 0.1	$ 0.1	$ 0.1
Issuance of common stock through employee stock plans (in shares)	500			2,000
Issuance of common stock through employee stock plans		0.6	$ 2
Shares withheld related to net share settlement of equity awards			(300)	300
Repurchase and retirement of common stock (in shares)				(600)
Repurchase and retirement of common stock		$ (0.2)	$ (0.2)
Ending balance (in shares)	117,500	115,600	117,500	115,600
Ending balance	$ 0.1	$ 0.1	$ 0.1	$ 0.1
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	6,085.1	5,430.1	5,756.8	5,170.3
Issuance of common stock through employee stock plans	113.9	86.1	267.9	205.7
Shares withheld related to net share settlement of equity awards	(0.5)	(0.5)	(7.5)	(7.2)
Share-based compensation expense related to employee stock plans	105.8	88.9	292.3	246.6
Repurchase and retirement of common stock		(3.7)	(5.2)	(14.5)
Ending balance	6,304.3	5,600.9	6,304.3	5,600.9
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,633	1,819	2,494.5	1,521.7
Shares withheld related to net share settlement of equity awards	(9.7)	(7.4)	(157.8)	(145.7)
Repurchase and retirement of common stock		(65.8)	(94.8)	(255)
Net income attributable to Intuitive Surgical, Inc.	313.9	396.8	695.4	1,021.6
Ending balance	2,937.2	2,142.6	2,937.2	2,142.6
Retained Earnings \| Adoption of new accounting standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(0.1)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	22.3	16.1	12.4	(13.3)
Other comprehensive income (loss)	(6.1)	1.7	3.8	31.1
Ending balance	16.2	17.8	16.2	17.8
Total Intuitive Surgical, Inc. Stockholders’ Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	8,740.5	7,265.3	8,263.8	6,678.8
Issuance of common stock through employee stock plans	113.9	86.1	267.9	205.7
Shares withheld related to net share settlement of equity awards	(10.2)	(7.9)	(165.3)	(152.9)
Share-based compensation expense related to employee stock plans	105.8	88.9	292.3	246.6
Repurchase and retirement of common stock		(69.5)	(100)	(269.5)
Net income attributable to Intuitive Surgical, Inc.	313.9	396.8	695.4	1,021.6
Other comprehensive income (loss)	(6.1)	1.7	3.8	31.1
Ending balance	9,257.8	7,761.4	9,257.8	7,761.4
Total Intuitive Surgical, Inc. Stockholders’ Equity \| Adoption of new accounting standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(0.1)
Noncontrolling Interest in Joint Venture
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	25.9	14.3	20.9	8.7
Other comprehensive income (loss)	0.1	(0.5)	0.2	(0.5)
Capital contribution from noncontrolling interest				10
Net income attributable to noncontrolling interest in joint venture	2.9	1.9	7.8	(2.5)
Ending balance	$ 28.9	$ 15.7	$ 28.9	$ 15.7

STOCKHOLDERS' EQUITY - Schedu_2

STOCKHOLDERS' EQUITY - Schedule of Share Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Value of shares repurchased		$ 69.5	$ 100	$ 269.5
Common Stock
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)				0.6
Value of shares repurchased		$ 0.2	$ 0.2
Common Stock \| Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)	0	0.2	0.2	0.6
Average price per share (in dollars per share)	$ 0	$ 492.94	$ 521.83	$ 481.35
Value of shares repurchased	$ 0	$ 69.5	$ 100	$ 269.5

STOCKHOLDERS' EQUITY - Stock Re

STOCKHOLDERS' EQUITY - Stock Repurchase Program (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jan. 31, 2019
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock	$ 100,000,000	$ 269,500,000
Repurchase Program \| Common Stock
Equity, Class of Treasury Stock [Line Items]
Amount of share repurchases authorized	7,500,000,000
Stock repurchase program, increased to authorized amount			$ 2,000,000,000
Remaining amount of share repurchases authorized	$ 1,600,000,000

STOCKHOLDERS' EQUITY - Componen

STOCKHOLDERS' EQUITY - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Gains (Losses) on Hedge Instruments
Beginning balance	$ 0.4	$ 0.5	$ 0.7	$ 0.2
Other comprehensive income (loss) before reclassifications	(0.8)	4.1	2	7.4
Amounts reclassified from accumulated other comprehensive income (loss)	(0.6)	(1)	(3.7)	(4)
Net current-period other comprehensive income (loss)	(1.4)	3.1	(1.7)	3.4
Ending balance	(1)	3.6	(1)	3.6
Unrealized Gains (Losses) on Available-for-Sale Securities
Beginning balance	44.1	19.7	20.4	(9.8)
Other comprehensive income (loss) before reclassifications	(7.1)	1.7	21.3	31.3
Amounts reclassified from accumulated other comprehensive income (loss)	0	(0.2)	(4.7)	(0.3)
Net current-period other comprehensive income (loss)	(7.1)	1.5	16.6	31
Ending balance	37	21.2	37	21.2
Foreign Currency Translation Gains (Losses)
Beginning balance	(13.8)	(0.8)	0	(0.3)
Other comprehensive income (loss) before reclassifications	2.2	(3)	(11.6)	(3.5)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Net current-period other comprehensive income (loss)	2.2	(3)	(11.6)	(3.5)
Ending balance	(11.6)	(3.8)	(11.6)	(3.8)
Employee Benefit Plans
Beginning balance	(8.4)	(3.3)	(8.7)	(3.4)
Other comprehensive income (loss) before reclassifications	0	0	0	(0.1)
Amounts reclassified from accumulated other comprehensive income (loss)	0.2	0.1	0.5	0.3
Net current-period other comprehensive income (loss)	0.2	0.1	0.5	0.2
Ending balance	(8.2)	(3.2)	(8.2)	(3.2)
Total
Beginning balance	22.3	16.1	12.4	(13.3)
Other comprehensive income (loss) before reclassifications	(5.7)	2.8	11.7	35.1
Amounts reclassified from accumulated other comprehensive income (loss)	(0.4)	(1.1)	(7.9)	(4)
Net current-period other comprehensive income (loss)	(6.1)	1.7	3.8	31.1
Ending balance	$ 16.2	$ 17.8	$ 16.2	$ 17.8

SHARE-BASED COMPENSATION - Addi

SHARE-BASED COMPENSATION - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Apr. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercisable, number of shares	3,600,000
Options exercisable, weighted-average exercise price (usd per share)	$ 230.78
Employee Stock Purchase Plan, number of shares purchased by employees	200,000	200,000
2010 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			28,450,000	32,450,000
Number of shares reserved for future issuance	8,200,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeited (in shares)	100,000
Restricted Stock Units (RSUs) \| 2010 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for future issuance	3,600,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, value of shares purchased by employees	$ 71.2	$ 56.4

SHARE-BASED COMPENSATION - Summ

SHARE-BASED COMPENSATION - Summary of Stock Option Activity Under All Stock Plans (Details) shares in Millions	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Number Outstanding
Beginning balance, Number Outstanding \| shares	5.4
Options granted, Number Outstanding \| shares	0.5
Options exercised, Number Outstanding \| shares	(1.1)
Options forfeited/expired, Number Outstanding \| shares	(0.1)
Ending balance, Number Outstanding \| shares	4.7
Weighted Average Exercise Price Per Share
Beginning balance, Weighted Average Exercise Price Per Share \| $ / shares	$ 246.64
Options granted, Weighted Average Exercise Price Per Share \| $ / shares	619.59
Options exercised, Weighted Average Exercise Price Per Share \| $ / shares	174.40
Options forfeited/expired, Weighted Average Exercise Price Per Share \| $ / shares	478.67
Ending balance, Weighted Average Exercise Price Per Share \| $ / shares	$ 299.92

SHARE-BASED COMPENSATION - Su_2

SHARE-BASED COMPENSATION - Summary of RSU Activity (Details) - Restricted Stock Units (RSUs) shares in Millions	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Shares
Unvested beginning balance (in shares) \| shares	1.9
Granted (in shares) \| shares	0.7
Vested (in shares) \| shares	(0.7)
Forfeited (in shares) \| shares	(0.1)
Unvested ending balance (in shares) \| shares	1.8
Weighted Average Grant Date Fair Value
Unvested beginning balance (usd per share) \| $ / shares	$ 410.09
Granted (usd per share) \| $ / shares	540.05
Vested (usd per share) \| $ / shares	341.41
Forfeited (usd per share) \| $ / shares	463.48
Unvested ending balance (usd per share) \| $ / shares	$ 486.08

SHARE-BASED COMPENSATION - Stoc

SHARE-BASED COMPENSATION - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	$ 107	$ 89.3	$ 294.4	$ 248.2
Income tax benefit	22.3	18.1	61.2	51
Share-based compensation expense after income taxes	84.7	71.2	233.2	197.2
Total cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	23.3	18	60.8	49.7
Total cost of sales \| Cost of sales - products
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	16.2	12.4	43	34.8
Total cost of sales \| Cost of sales - services
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	7.1	5.6	17.8	14.9
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	54.2	44.7	149.5	124
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	$ 29.5	$ 26.6	$ 84.1	$ 74.5

SHARE-BASED COMPENSATION - Sche

SHARE-BASED COMPENSATION - Schedule of Estimated Fair Value of Option Using Black-Scholes Option Pricing Model, Weighted Average Assumptions (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.20%	1.50%	0.60%	2.00%
Expected term (in years)	3 years 10 months 24 days	3 years 10 months 24 days	4 years 1 month 6 days	4 years 1 month 6 days
Expected volatility (percent)	34.00%	30.00%	32.00%	30.00%
Weighted average fair value at grant date (usd per share)	$ 187.94	$ 127.19	$ 160.72	$ 142.22
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.10%	1.90%	0.90%	2.10%
Expected term (in years)	1 year 3 months 18 days	1 year 2 months 12 days	1 year 2 months 12 days	1 year 2 months 12 days
Expected volatility (percent)	34.00%	29.00%	30.00%	29.00%
Weighted average fair value at grant date (usd per share)	$ 203.56	$ 146.48	$ 171.87	$ 148.99

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details) - USD ($) $ in Millions	Jun. 22, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income tax expense (benefit)		$ 38.4	$ 0.3	$ 67.3	$ 51.4
Income tax expense, percentage of pre-tax income		10.80%	0.10%	8.70%	4.80%
Income Tax Contingency [Line Items]
Increase in unrecognized tax benefits	$ 36.8
Increase in income tax expense	$ 36.8
Swiss
Income Tax Contingency [Line Items]
Re-measurement of deferred tax assets		$ 51.3		$ 51.3

NET INCOME PER SHARE - Computat

NET INCOME PER SHARE - Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income attributable to Intuitive Surgical, Inc.	$ 313.9	$ 396.8	$ 695.4	$ 1,021.6
Denominator:
Weighted average shares outstanding used in basic calculation	117.3	115.4	116.8	115.3
Add: dilutive effect of potential common shares	3.3	3.9	3.2	4.1
Weighted average shares outstanding used in diluted calculation	120.6	119.3	120	119.4
Net income per share attributable to Intuitive Surgical, Inc.:
Basic (in dollars per share)	$ 2.68	$ 3.44	$ 5.95	$ 8.86
Diluted (in dollars per share)	$ 2.60	$ 3.33	$ 5.80	$ 8.56

NET INCOME PER SHARE - Addition

NET INCOME PER SHARE - Additional Information (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Employee stock options excluded from computation of diluted net income per share	0.2	0.8	0.9	0.6