Vertex Pharmaceuticals (VRTX) 10-Q 1 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 24, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	000-19319
Entity Registrant Name	VERTEX PHARMACEUTICALS INC / MA
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-3039129
Entity Address, Address Line One	50 Northern Avenue
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210
City Area Code	617
Local Phone Number	341-6100
Title of 12(b) Security	Common Stock, $0.01 Par Value Per Share
Trading Symbol	VRTX
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		259,276,709
Entity Central Index Key	0000875320
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenues	$ 1,515,107	$ 858,435
Costs and expenses:
Cost of sales	162,497	95,092
Research and development expenses	448,528	339,490
Sales, general and administrative expenses	182,258	147,045
Change in fair value of contingent consideration	1,600	0
Total costs and expenses	794,883	581,627
Income from operations	720,224	276,808
Interest income	12,576	15,615
Interest expense	(14,136)	(14,868)
Other (expense) income, net	(61,130)	42,610
Income before provision for income taxes	657,534	320,165
Provision for income taxes	54,781	51,534
Net income	$ 602,753	$ 268,631
Net income per common share:
Basic (in dollars per share)	$ 2.32	$ 1.05
Diluted (in dollars per share)	$ 2.29	$ 1.03
Shares used in per share calculations:
Basic (in shares)	259,815	255,695
Diluted (in shares)	263,515	260,175
Product revenues, net
Revenues:
Revenues	$ 1,515,107	$ 857,253
Collaborative and royalty revenues
Revenues:
Revenues	$ 0	$ 1,182

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 602,753	$ 268,631
Changes in other comprehensive income:
Unrealized holding (losses) gains on marketable securities, net	(764)	596
Unrealized gains (losses) on foreign currency forward contracts, net of tax of $(5.0) million and $1.5 million, respectively	18,782	(222)
Foreign currency translation adjustment	(2,662)	4,967
Total changes in other comprehensive income	15,356	5,341
Comprehensive income	$ 618,109	$ 273,972

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Unrealized (losses) gains on foreign currency forward contracts, tax	$ (5)	$ 1.5

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 3,593,412	$ 3,109,322
Marketable securities	596,984	698,972
Accounts receivable, net	845,269	633,518
Inventories	187,087	167,502
Prepaid expenses and other current assets	223,648	213,515
Total current assets	5,446,400	4,822,829
Property and equipment, net	736,303	745,080
Goodwill	1,002,158	1,002,158
Intangible assets	400,000	400,000
Deferred tax assets	1,147,705	1,190,815
Other assets	160,635	157,583
Total assets	8,893,201	8,318,465
Current liabilities:
Accounts payable	100,703	87,610
Accrued expenses	1,258,271	1,116,912
Other current liabilities	179,776	130,305
Total current liabilities	1,538,750	1,334,827
Long-term finance lease liabilities	532,952	538,576
Long-term contingent consideration	178,100	176,500
Other long-term liabilities	181,745	183,318
Total liabilities	2,431,547	2,233,221
Commitments and contingencies	0	0
Shareholders’ equity:
Preferred stock, $0.01 par value; 1,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.01 par value; 500,000 shares authorized, 259,079 and 258,993 shares issued and outstanding, respectively	2,591	2,589
Additional paid-in capital	7,695,905	7,937,606
Accumulated other comprehensive income (loss)	13,383	(1,973)
Accumulated deficit	(1,250,225)	(1,852,978)
Total shareholders’ equity	6,461,654	6,085,244
Total liabilities and shareholders’ equity	$ 8,893,201	$ 8,318,465

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	259,079,000	258,993,000
Common stock, shares outstanding	259,079,000	258,993,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (shares) at Dec. 31, 2018		255,172
Beginning balance at Dec. 31, 2018	$ 4,435,203	$ 2,546	$ 7,421,476	$ 659	$ (2,989,478)
Increase (Decrease) in Stockholders' Equity
Other comprehensive income, net of tax	5,341			5,341
Net income	268,631				268,631
Repurchases of common stock (in shares)		(537)
Repurchase of common stock	(98,007)	$ (6)	(98,001)
Common stock withheld for employee tax obligations (shares)		(27)
Common stock withheld for employee tax obligations	(5,832)		(5,832)
Issuance of common stock under benefit plans (shares)		1,743
Issuance of common stock under benefit plans	64,044	$ 21	64,023
Stock-based compensation expense	94,243		94,243
Ending balance (shares) at Mar. 31, 2019		256,351
Ending Balance at Mar. 31, 2019	4,723,313	$ 2,561	7,475,909	6,000	(2,761,157)
Beginning balance (shares) at Dec. 31, 2019		258,993
Beginning balance at Dec. 31, 2019	6,085,244	$ 2,589	7,937,606	(1,973)	(1,852,978)
Increase (Decrease) in Stockholders' Equity
Other comprehensive income, net of tax	15,356			15,356
Net income	602,753				602,753
Repurchases of common stock (in shares)		(1,404)
Repurchase of common stock	(300,026)	$ (14)	(300,012)
Common stock withheld for employee tax obligations (shares)		(575)
Common stock withheld for employee tax obligations	(136,167)	$ (6)	(136,161)
Issuance of common stock under benefit plans (shares)		2,065
Issuance of common stock under benefit plans	77,594	$ 22	77,572
Stock-based compensation expense	116,900		116,900
Ending balance (shares) at Mar. 31, 2020		259,079
Ending Balance at Mar. 31, 2020	$ 6,461,654	$ 2,591	$ 7,695,905	$ 13,383	$ (1,250,225)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 602,753	$ 268,631
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	115,706	93,791
Depreciation expense	26,821	27,140
Increase in fair value of contingent consideration	1,600	0
Deferred income taxes	36,705	43,425
Losses (gains) on equity securities	44,870	(43,551)
Other non-cash items, net	9,668	(2,431)
Changes in operating assets and liabilities:
Accounts receivable, net	(223,672)	(30,136)
Inventories	(27,450)	(13,139)
Prepaid expenses and other assets	2,790	7,941
Accounts payable	14,285	(24,145)
Accrued expenses	153,814	(27,279)
Other liabilities	57,808	24,537
Net cash provided by operating activities	815,698	324,784
Cash flows from investing activities:
Purchases of available-for-sale debt securities	(75,265)	(128,215)
Maturities of available-for-sale debt securities	60,145	107,118
Sale of equity securities	72,036	0
Expenditures for property and equipment	(19,450)	(18,041)
Investment in equity securities	(5,800)	0
Net cash provided by (used in) investing activities	31,666	(39,138)
Cash flows from financing activities:
Issuances of common stock under benefit plans	79,597	63,620
Repurchases of common stock	(300,026)	(94,007)
Payments in connection with common stock withheld for employee tax obligations	(136,167)	(5,832)
Payments on finance leases	(10,287)	(9,385)
Proceeds related to finance leases	5,833	0
Advance from collaborator	2,500	5,000
Repayments of advanced funding	(880)	(1,385)
Net cash used in financing activities	(359,430)	(41,989)
Effect of changes in exchange rates on cash	(6,651)	(378)
Net increase in cash and cash equivalents	481,283	243,279
Cash, cash equivalents and restricted cash—beginning of period	3,120,681	2,658,253
Cash, cash equivalents and restricted cash—end of period	3,601,964	2,901,532
Supplemental disclosure of cash flow information:
Cash paid for interest	13,771	13,148
Cash paid for income taxes	5,845	1,835
Issuances of common stock from employee benefit plans receivable	817	510
Accrued share repurchase liability	$ 0	$ 4,000

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Accounting Policies	Basis of Presentation and Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements are unaudited and have been prepared by Vertex Pharmaceuticals Incorporated (“Vertex” or the “Company”) in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The condensed consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiaries. All material intercompany balances and transactions have been eliminated. The Company operates in one segment, pharmaceuticals. The Company has reclassified certain items from the prior year’s condensed consolidated financial statements to conform to the current year’s presentation. Certain information and footnote disclosures normally included in the Company’s 2019 Annual Report on Form 10-K have been condensed or omitted. These interim financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the financial position and results of operations for the interim periods ended March 31, 2020 and 2019 . The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full fiscal year. These interim financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2019 , which are contained in the Company’s 2019 Annual Report on Form 10-K. Use of Estimates The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the amounts of revenues and expenses during the reported periods. Significant estimates in these condensed consolidated financial statements have been made in connection with (i) determining the transaction price of revenues and (ii) accounting for intangible assets and contingent consideration. The Company bases its estimates on historical experience and various other assumptions, including in certain circumstances future projections that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known. Recently Adopted Accounting Standards Leases On January 1, 2019, the Company adopted Accounting Standards Codification (“ASC”) 842, Leases (“ASC 842”) using the modified-retrospective method, which amended a number of aspects of lease accounting and required the Company to recognize right-of-use assets and liabilities on the balance sheet. As of January 1, 2019, the Company recorded a cumulative effect adjustment to increase its “ Accumulated deficit ” by $40.3 million , which related to its leases that were accounted for as build-to-suit leases under the previous accounting guidance. Internal-Use Software In 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”), which clarifies the accounting for implementation costs in cloud computing arrangements. ASU 2018-15 became effective on January 1, 2020. The adoption of ASU 2018-15 resulted in an insignificant amount of additional assets recorded on the Company’s condensed consolidated balance sheet. Fair Value Measurement In 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which modifies the disclosure requirements for fair value measurements. ASU 2018-13 became effective on January 1, 2020. The adoption of ASU 2018-13 resulted in additional disclosures related to the Company’s Level 3 inputs. Please refer to Note E, “Fair Value Measurements,” for further information. Credit Losses In 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires entities to record expected credit losses for certain financial instruments, including trade receivables, as an allowance that reflects the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities in unrealized loss positions, ASU 2016-13 requires allowances to be recorded instead of reducing the amortized cost of the investment. ASU 2016-13 became effective on January 1, 2020. The adoption of ASU 2016-13 did not have a significant impact on its condensed consolidated financial statements. Recently Issued Accounting Standards Income Taxes In 2019, the FASB issued ASU 2019-12 , Income Taxes (Topic 740) (“ ASU 2019-12 ”), which simplifies the accounting for income taxes. ASU 2019-12 is effective on January 1, 2021. The Company is evaluating the impact the adoption of ASU 2019-12 may have on its condensed consolidated financial statements. For a discussion of other recent accounting pronouncements please refer to Note A, “Nature of Business and Accounting Policies,” in the Company’s 2019 Annual Report on Form 10-K. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note A, “Nature of Business and Accounting Policies,” in its 2019

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Disaggregation of Revenue Revenues by Product Product revenues, net consisted of the following: Three Months Ended March 31, 2020 2019 (in thousands) TRIKAFTA $ 895,233 $ — SYMDEKO/SYMKEVI 173,159 320,275 ORKAMBI 234,138 293,007 KALYDECO 212,577 243,971 Total product revenues, net * $ 1,515,107 $ 857,253 * The preceding table does not include collaborative and royalty revenues. Revenues by Geographic Location Net product revenues are attributed to countries based on the location of the customer. Collaborative and royalty revenues are attributed to countries based on the location of the Company’s subsidiary associated with the collaborative arrangement related to such revenues. Total revenues from external customers and collaborators by geographic region consisted of the following: Three Months Ended March 31, 2020 2019 (in thousands) United States $ 1,187,588 $ 641,104 Outside of the United States Europe 257,391 167,751 Other 70,128 49,580 Total revenues outside of the United States 327,519 217,331 Total revenues $ 1,515,107 $ 858,435 Contract Liabilities The Company recorded contract liabilities of $76.3 million and $62.3 million as of March 31, 2020 and December 31, 2019 , respectively, related to annual contracts with government-owned and supported customers in international markets that limit the amount of annual reimbursement the Company can receive. Upon exceeding the annual reimbursement amount, products are provided free of charge, which is a material right. These contracts include upfront payments and fees. The Company defers a portion of the consideration received for shipments made up to the annual reimbursement limit as a portion of “ Other current liabilities .” The deferred amount is recognized as revenue when the free products are shipped. The Company’s product revenue contracts include performance obligations that are one year or less. The Company’s contract liabilities at the end of each fiscal year relate to contracts with annual reimbursement limits in international markets in which the annual period associated with the contract is not the same as the Company’s fiscal year. In these markets, the Company recognizes revenues related to performance obligations satisfied in previous years; however, these revenues do not relate to any performance obligations that were satisfied more than 12 months prior to the beginning of the current year.

Collaborative Arrangements

Collaborative Arrangements	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements	Collaborative Arrangements The Company has entered into numerous agreements pursuant to which it collaborates with third parties on research, development and commercialization programs, including in-license and out-license agreements. The Company’s in-license and out-license agreements that had a significant impact on its financial statements for the three months ended March 31, 2020 and 2019 , or were new during the three months ended March 31, 2020 , are described below. Additional in-license and out-license agreements were described in Note B, “Collaborative Arrangements,” of the Company’s 2019 Annual Report on Form 10-K. In-license Agreements The Company has entered into a number of license agreements in order to advance and obtain access to technologies and services related to its research and early-development activities. The Company is generally required to make an upfront payment upon execution of the license agreement; development, regulatory and commercialization milestones payments upon the achievement of certain product research, development and commercialization objectives; and royalty payments on future sales, if any, of commercial products resulting from the collaboration. Pursuant to the terms of its in-license agreements, the Company’s collaborators typically lead the discovery efforts and the Company leads all preclinical, development and commercialization activities associated with the advancement of any drug candidates and funds all expenses. The Company typically can terminate its in-license agreements by providing advance notice to its collaborators; the required length of notice is dependent on whether any product developed under the license agreement has received marketing approval. The Company’s license agreements may be terminated by either party for a material breach by the other, subject to notice and cure provisions. Unless earlier terminated, these license agreements generally remain in effect until the date on which the royalty term and all payment obligations with respect to all products in all countries have expired. CRISPR Therapeutics AG In 2015, the Company entered into a strategic collaboration, option and license agreement (the “CRISPR Agreement”) with CRISPR Therapeutics AG and its affiliates (“CRISPR”) to collaborate on the discovery and development of potential new treatments aimed at the underlying genetic causes of human diseases using CRISPR-Cas9 gene-editing technology. The Company had the exclusive right to license certain CRISPR-Cas9-based targets. In the fourth quarter of 2019, the Company elected to exclusively license three CRISPR-Cas9-based targets, including cystic fibrosis, pursuant to the CRISPR Agreement. For each of the three targets that the Company elected to license, CRISPR has the potential to receive up to an additional $410.0 million in development, regulatory and commercial milestones as well as royalties on net product sales. In 2017, the Company entered into a co-development and co-commercialization agreement with CRISPR pursuant to the terms of the CRISPR Agreement, under which the Company and CRISPR are co-developing and will co-commercialize CTX001 (the “CTX001 Co-Co Agreement”) for the treatment of hemoglobinopathies, including treatments for sickle cell disease and beta thalassemia. As part of the collaboration, the Company and CRISPR share equally all development costs and potential worldwide revenues related to potential hemoglobinopathy treatments. The Company concluded that the CTX001 Co-Co Agreement is a cost-sharing arrangement, which results in the net impact of the arrangement being recorded in “ Research and development expenses ” in its condensed consolidated statements of operations. During the three months ended March 31, 2020 and 2019 , the net expense related to the CTX001 Co-Co Agreement was $9.3 million and $7.0 million , respectively. In July 2019, the Company entered into a separate strategic collaboration and license agreement (the “CRISPR DMD/DM1 Agreement”) with CRISPR. Pursuant to this agreement, the Company received an exclusive worldwide license to CRISPR’s existing and future intellectual property for duchenne muscular dystrophy (“DMD”) and myotonic dystrophy type 1 (“DM1”). In the first quarter of 2020, the Company recorded $25.0 million to “ Research and development expenses ” related to a pre-clinical milestone earned by CRISPR under the CRISPR DMD/DM1 Agreement. CRISPR has the potential to receive up to an additional $800.0 million in research, development, regulatory and commercial milestones for the DMD and DM1 programs as well as royalties on net product sales. CRISPR has the option to co-develop and co-commercialize all DM1 products globally and forego the milestones and royalties associated with the DM1 program. The Company funds all expenses associated with the collaboration except for research costs for specified guide RNA research conducted by CRISPR, which the Company and CRISPR share equally. Please refer to Note F, “Marketable Securities and Equity Investments,” for further information regarding the Company’s investment in CRISPR’s common stock. Out-license Agreements The Company has entered into licensing agreements pursuant to which it has out-licensed rights to certain drug candidates to third-party collaborators. Pursuant to these out-license agreements, the Company’s collaborators become responsible for all costs related to the continued development of such drug candidates and obtain development and commercialization rights to these drug candidates. Depending on the terms of the agreements, the Company’s collaborators may be required to make upfront payments, milestone payments upon the achievement of certain product research and development objectives and may also be required to pay royalties on future sales, if any, of commercial products resulting from the collaboration. The termination provisions associated with these collaborations are generally the same as those described above related to the Company’s in-license agreements. None of the Company’s out-license agreements had a significant impact on the Company’s condensed consolidated statement of operations during the three months ended March 31, 2020 and 2019 . Cystic Fibrosis Foundation

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic net income per common share is based upon the weighted-average number of common shares outstanding. Diluted net income per common share utilizing the treasury method is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average common equivalent shares outstanding during the period when the effect is dilutive. The following table sets forth the computation of basic and diluted net income per common share for the periods ended: Three Months Ended March 31, 2020 2019 (in thousands, except per share amounts) Net income $ 602,753 $ 268,631 Basic weighted-average common shares outstanding 259,815 255,695 Effect of potentially dilutive securities: Stock options 1,868 2,585 Restricted stock and restricted stock units (including PSUs) 1,801 1,870 Employee stock purchase program 31 25 Diluted weighted-average common shares outstanding 263,515 260,175 Basic net income per common share $ 2.32 $ 1.05 Diluted net income per common share $ 2.29 $ 1.03 The Company did not include the securities in the following table in the computation of the net income per common share because the effect would have been anti-dilutive during each period: Three Months Ended March 31, 2020 2019 (in thousands) Stock options 879 2,837 Unvested restricted stock and restricted stock units (including PSUs) 430 6

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value of the Company’s financial assets and liabilities reflects the Company’s estimate of amounts that it would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. In connection with measuring the fair value of its assets and liabilities, the Company seeks to maximize the use of observable inputs (market data obtained from sources independent from the Company) and to minimize the use of unobservable inputs (the Company’s assumptions about how market participants would price assets and liabilities). The following fair value hierarchy is used to classify assets and liabilities based on the observable inputs and unobservable inputs used in order to value the assets and liabilities: Level 1: Quoted prices in active markets for identical assets or liabilities. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2: Observable inputs other than Level 1 inputs. Examples of Level 2 inputs include quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active. Level 3: Unobservable inputs based on the Company’s assessment of the assumptions that market participants would use in pricing the asset or liability. The Company’s investment strategy is focused on capital preservation. The Company invests in instruments that meet the credit quality standards outlined in the Company’s investment policy. This policy also limits the amount of credit exposure to any one issue or type of instrument. The Company maintains strategic investments separately from the investment policy that governs its other cash, cash equivalents and marketable securities as described in “ Note F, “Marketable Securities and Equity Investments.” As of March 31, 2020 , the Company’s investments were in money market funds, corporate debt securities, commercial paper, government-sponsored enterprise securities and corporate equity securities. Additionally, the Company utilizes foreign currency forward contracts intended to mitigate the effect of changes in foreign exchange rates on its condensed consolidated statement of operations. As of March 31, 2020 , the Company’s financial assets and liabilities that were subject to fair value measurements were valued using both observable and unobservable inputs. The Company’s financial assets valued based on Level 1 inputs consisted of money market funds, government-sponsored enterprise securities and corporate equity securities. The Company’s financial assets and liabilities valued based on Level 2 inputs consisted of certain corporate equity securities as described below, corporate debt securities, commercial paper, which consisted of investments in highly-rated investment-grade corporations, and foreign currency forward contracts with reputable and creditworthy counterparties. As discussed further below, the Company’s financial liabilities valued based on Level 3 inputs consisted of acquisition-related contingent milestones. During the three months ended March 31, 2020 and 2019 , the Company did not record any other-than-temporary impairment charges related to its financial assets. The following tables set forth the Company’s financial assets and liabilities subject to fair value measurements (and does not include $1.8 billion and $ 2.3 billion of cash as of March 31, 2020 and December 31, 2019 , respectively): Fair Value Measurements as of March 31, 2020 Fair Value Hierarchy Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 1,736,913 $ 1,736,913 $ — $ — Commercial paper 30,700 — 30,700 — Marketable securities: Corporate equity securities 165,178 145,465 19,713 — Government-sponsored enterprise securities 7,791 7,791 — — Corporate debt securities 305,051 — 305,051 — Commercial paper 118,964 — 118,964 — Prepaid expenses and other current assets: Foreign currency forward contracts 25,434 — 25,434 — Other assets: Foreign currency forward contracts 1,798 — 1,798 — Total financial assets $ 2,391,829 $ 1,890,169 $ 501,660 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (459 ) $ — $ (459 ) $ — Long-term contingent consideration (178,100 ) — — (178,100 ) Other long-term liabilities: Foreign currency forward contracts (637 ) — (637 ) — Total financial liabilities $ (179,196 ) $ — $ (1,096 ) $ (178,100 ) Fair Value Measurements as of December 31, 2019 Fair Value Hierarchy Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 791,039 $ 791,039 $ — $ — Corporate debt securities 6,070 — 6,070 — Commercial paper 29,472 — 29,472 — Marketable securities: Corporate equity securities 282,084 261,797 20,287 — Government-sponsored enterprise securities 12,733 12,733 — — Corporate debt securities 301,799 — 301,799 — Commercial paper 102,356 — 102,356 — Prepaid expenses and other current assets: Foreign currency forward contracts 9,725 — 9,725 — Total financial assets $ 1,535,278 $ 1,065,569 $ 469,709 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (5,533 ) $ — $ (5,533 ) $ — Long-term contingent consideration (176,500 ) — — (176,500 ) Other long-term liabilities: Foreign currency forward contracts (1,821 ) — (1,821 ) — Total financial liabilities $ (183,854 ) $ — $ (7,354 ) $ (176,500 ) Please refer to Note F, “Marketable Securities and Equity Investments,” for the carrying amount and related unrealized gains (losses) by type of investment. Fair Value of Corporate Equity Securities The Company maintains strategic investments in corporate equity securities separately from the investment policy that governs its other cash, cash equivalents and marketable securities. The Company classifies its investments in publicly traded companies as “ Marketable securities ” on its condensed consolidated balance sheets. Generally, the Company’s investments in the common stock of these publicly traded companies are valued based on Level 1 inputs because they have readily determinable fair values. However, certain of the Company’s investments in publicly traded companies have been or continue to be valued based on Level 2 inputs due to transfer restrictions associated with these investments. Please refer to Note F, “Marketable Securities and Equity Investments,” for further information on these investments. Fair Value of Contingent Consideration The Company’s contingent consideration liabilities, which are related to $678.3 million of development and regulatory milestones potentially payable to Exonics’ former equity holders, are classified as Level 3 within the valuation hierarchy. The Company bases its estimates of the probability of achieving the milestones relevant to the fair value of contingent payments on industry data attributable to rare diseases. The discount rates used in the valuation model for contingent payments, which were between 1.8% and 3.1% , represent a measure of credit risk and market risk associated with settling the liabilities. Significant judgment is used in determining the appropriateness of these assumptions at each reporting period. Due to the uncertainties associated with development and commercialization of a drug candidate in the pharmaceutical industry, the Company's estimates regarding the fair value of contingent consideration will change in the future, resulting in adjustments to the fair value of the Company’s contingent consideration liabilities, and the effect of any such adjustments could be material. The following table represents a rollforward of the fair value of the Company’s contingent consideration liabilities: Three Months Ended March 31, 2020 (in thousands) Balance at December 31, 2019 $ 176,500 Increase in fair value of contingent payments 1,600 Balance at March 31, 2020 $ 178,100 The “ Increase in fair value of contingent payments

Marketable Securities and Equit

Marketable Securities and Equity Investments	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Marketable Securities and Equity Investments	Marketable Securities and Equity Investments A summary of the Company’s cash equivalents and marketable securities, which are recorded at fair value (and do not include $1.8 billion and $ 2.3 billion of cash as of March 31, 2020 and December 31, 2019 , respectively), is shown below: Amortized Cost Gross Gross Fair Value (in thousands) As of March 31, 2020 Cash equivalents: Money market funds $ 1,736,913 $ — $ — $ 1,736,913 Commercial paper 30,700 4 (4 ) 30,700 Total cash equivalents 1,767,613 4 (4 ) 1,767,613 Marketable securities: Government-sponsored enterprise securities 7,717 74 — 7,791 Corporate debt securities 305,808 255 (1,012 ) 305,051 Commercial paper 118,542 426 (4 ) 118,964 Total marketable debt securities 432,067 755 (1,016 ) 431,806 Corporate equity securities 87,096 78,082 — 165,178 Total marketable securities $ 519,163 $ 78,837 $ (1,016 ) $ 596,984 As of December 31, 2019 Cash equivalents: Money market funds $ 791,039 $ — $ — $ 791,039 Corporate debt securities 6,070 — — 6,070 Commercial paper 29,470 3 (1 ) 29,472 Total cash equivalents 826,579 3 (1 ) 826,581 Marketable securities: Government-sponsored enterprise securities 12,689 44 — 12,733 Corporate debt securities 301,458 391 (50 ) 301,799 Commercial paper 102,240 121 (5 ) 102,356 Total marketable debt securities 416,387 556 (55 ) 416,888 Corporate equity securities 113,829 168,255 — 282,084 Total marketable securities $ 530,216 $ 168,811 $ (55 ) $ 698,972 Available-for-sale debt securities were classified on the Company's condensed consolidated balance sheets at fair value as follows: As of March 31, 2020 As of December 31, 2019 (in thousands) Cash and cash equivalents $ 1,767,613 $ 826,581 Marketable securities 431,806 416,888 Total $ 2,199,419 $ 1,243,469 Available-for-sale debt securities by contractual maturity were as follows: As of March 31, 2020 As of December 31, 2019 (in thousands) Matures within one year $ 2,157,586 $ 1,137,942 Matures after one year through five years 41,833 105,527 Total $ 2,199,419 $ 1,243,469 The Company has a limited number of available-for-sale debt securities in insignificant loss positions as of March 31, 2020 , which it does not intend to sell and has concluded it will not be required to sell before recovery of the amortized costs for the investments at maturity. The Company did no t record any charges for other-than-temporary declines in the fair value of available-for-sale debt securities or gross realized gains or losses in the three months ended March 31, 2020 and 2019 . As of March 31, 2020 and December 31, 2019 , the total fair value of the Company’s strategic investments in the common stock of publicly traded companies, which was primarily related to its investment in CRISPR, was $165.2 million and $282.1 million , respectively, and was classified as “ Marketable securities ” on its condensed consolidated balance sheets. The Company records changes in the fair value of its investments in corporate equity securities, which are primarily attributable to its investment in CRISPR, to “ Other (expense) income, net ” on its condensed consolidated statements of operations. During the three months ended March 31, 2020 and 2019 , the Company recorded a net unrealized loss of $39.4 million and a net unrealized gain of $43.6 million , respectively, on corporate equity securities held at the conclusion of each period. During the three months ended March 31, 2020 , the Company received proceeds of $72.0 million related to sales of CRISPR’s common stock, which had an original weighted-average cost basis of $26.7 million . There were no sales of CRISPR’s common stock during the three months ended March 31, 2019 . As of March 31, 2020 , the carrying value of the Company’s equity investments without readily determinable fair values, which are recorded in “ Other assets ” on its condensed consolidated balance sheets, was $46.6 million .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The following table summarizes the changes in accumulated other comprehensive income (loss) by component: Unrealized Holding Gains (Losses), Net of Tax Foreign Currency Translation Adjustment On Available-For-Sale Debt Securities On Foreign Currency Forward Contracts Total (in thousands) Balance at December 31, 2019 $ (895 ) $ 503 $ (1,581 ) $ (1,973 ) Other comprehensive (loss) income before reclassifications (2,662 ) (764 ) 25,772 22,346 Amounts reclassified from accumulated other comprehensive income (loss) — — (6,990 ) (6,990 ) Net current period other comprehensive (loss) income (2,662 ) (764 ) 18,782 15,356 Balance at March 31, 2020 $ (3,557 ) $ (261 ) $ 17,201 $ 13,383 Balance at December 31, 2018 $ (11,227 ) $ (536 ) $ 12,422 $ 659 Other comprehensive income before reclassifications 4,967 596 5,126 10,689 Amounts reclassified from accumulated other comprehensive income — — (5,348 ) (5,348 ) Net current period other comprehensive income (loss) 4,967 596 (222 ) 5,341 Balance at March 31, 2019 $ (6,260 ) $ 60 $ 12,200 $ 6,000

Hedging

Hedging	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Hedging	Hedging Foreign currency forward contracts - Designated as hedging instruments The Company maintains a hedging program intended to mitigate the effect of changes in foreign exchange rates for a portion of the Company’s forecasted product revenues denominated in certain foreign currencies. The program includes foreign currency forward contracts that are designated as cash flow hedges under GAAP having contractual durations from one to eighteen months . The Company recognizes realized gains and losses for the effective portion of such contracts in “ Product revenues, net ” in its condensed consolidated statements of operations in the same period that it recognizes the product revenues that were impacted by the hedged foreign exchange rate changes. The Company formally documents the relationship between foreign currency forward contracts (hedging instruments) and forecasted product revenues (hedged items), as well as the Company’s risk management objective and strategy for undertaking various hedging activities, which includes matching all foreign currency forward contracts that are designated as cash flow hedges to forecasted transactions. The Company also formally assesses, both at the hedge’s inception and on an ongoing basis, whether the foreign currency forward contracts are highly effective in offsetting changes in cash flows of hedged items on a prospective and retrospective basis. If the Company were to determine that a (i) foreign currency forward contract is not highly effective as a cash flow hedge, (ii) foreign currency forward contract has ceased to be a highly effective hedge or (iii) forecasted transaction is no longer probable of occurring, the Company would discontinue hedge accounting treatment prospectively. The Company measures effectiveness based on the change in fair value of the forward contracts and the fair value of the hypothetical foreign currency forward contracts with terms that match the critical terms of the risk being hedged. As of March 31, 2020 , all hedges were determined to be highly effective. The Company considers the impact of its counterparties’ credit risk on the fair value of the foreign currency forward contracts. As of March 31, 2020 and December 31, 2019 , credit risk did not change the fair value of the Company’s foreign currency forward contracts. The following table summarizes the notional amount of the Company’s outstanding foreign currency forward contracts designated as cash flow hedges under GAAP: As of March 31, 2020 As of December 31, 2019 Foreign Currency (in thousands) Euro $ 581,764 $ 501,197 British pound sterling 124,160 87,032 Australian dollar 74,643 89,705 Canadian dollar 46,390 50,452 Total foreign currency forward contracts $ 826,957 $ 728,386 Foreign currency forward contracts - Not designated as hedging instruments The Company also enters into foreign currency forward contracts with contractual maturities of less than one month , that are designed to mitigate the effect of changes in foreign exchange rates on monetary assets and liabilities, including intercompany balances. These contracts are not designated as hedging instruments under GAAP. The Company recognizes realized gains and losses for such contracts in “ Other (expense) income, net ” in its condensed consolidated statements of operations each period. As of March 31, 2020 , the notional amount of the Company’s outstanding foreign currency forward contracts where hedge accounting under GAAP is not applied was $522.2 million . During the three months ended March 31, 2020 and 2019 , the Company recognized the following related to foreign currency forward contacts in its condensed consolidated statements of operations: Three Months Ended March 31, 2020 2019 (in thousands) Designated as hedging instruments - Reclassified from AOCI Product revenues, net $ 8,922 $ 6,839 Not designated as hedging instruments Other (expense) income, net $ 16,229 $ 3,151 Total reported in the Condensed Consolidated Statement of Operations Product revenues, net $ 1,515,107 $ 857,253 Other (expense) income, net $ (61,130 ) $ 42,610 The following table summarizes the fair value of the Company’s outstanding foreign currency forward contracts designated as cash flow hedges under GAAP included on its condensed consolidated balance sheets: As of March 31, 2020 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 25,434 Other current liabilities $ (459 ) Other assets 1,798 Other long-term liabilities (637 ) Total assets $ 27,232 Total liabilities $ (1,096 ) As of December 31, 2019 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 9,725 Other current liabilities $ (5,533 ) Other assets — Other long-term liabilities (1,821 ) Total assets $ 9,725 Total liabilities $ (7,354 ) As of March 31, 2020 , the Company expects the amounts that are related to foreign exchange forward contracts designated as cash flow hedges under GAAP recorded in “ Prepaid expenses and other current assets ” and “ Other current liabilities ” to be reclassified to earnings within twelve months. The following table summarizes the potential effect of offsetting derivatives by type of financial instrument designated as cash flow hedges under GAAP on the Company’s condensed consolidated balance sheets: As of March 31, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 27,232 $ — $ 27,232 $ (1,096 ) $ 26,136 Total liabilities (1,096 ) — (1,096 ) 1,096 — As of December 31, 2019 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 9,725 $ — $ 9,725 $ (7,354 ) $ 2,371 Total liabilities (7,354 ) — (7,354 ) 7,354 —

Inventories

Inventories	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following: As of March 31, 2020 As of December 31, 2019 (in thousands) Raw materials $ 24,835 $ 26,247 Work-in-process 117,427 107,021 Finished goods 44,825 34,234 Total $ 187,087 $ 167,502

Stock-based Compensation Expens

Stock-based Compensation Expense and Share Repurchase Programs	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-based Compensation Expense and Share Repurchase Programs	Stock-based Compensation Expense and Share Repurchase Programs Stock-based compensation expense During the three months ended March 31, 2020 and 2019 , the Company recognized the following stock-based compensation expense: Three Months Ended March 31, 2020 2019 (in thousands) Stock-based compensation expense by type of award: Restricted stock and restricted stock units (including PSUs) $ 97,149 $ 63,510 Stock options 17,266 28,156 ESPP share issuances 2,485 2,577 Stock-based compensation expense related to inventories (1,194 ) (452 ) Total stock-based compensation expense included in costs and expenses $ 115,706 $ 93,791 Stock-based compensation expense by line item: Cost of sales $ 1,361 $ 1,338 Research and development expenses 72,687 59,715 Sales, general and administrative expenses 41,658 32,738 Total stock-based compensation expense included in costs and expenses 115,706 93,791 Income tax effect (64,246 ) (39,524 ) Total stock-based compensation expense, net of tax $ 51,460 $ 54,267 The following table sets forth the Company’s unrecognized stock-based compensation expense as of March 31, 2020 , by type of award and the weighted-average period over which that expense is expected to be recognized: As of March 31, 2020 Unrecognized Expense Weighted-average (in thousands) (in years) Type of award: Restricted stock and restricted stock units (including PSUs) $ 550,095 2.27 Stock options $ 109,086 2.33 ESPP share issuances $ 2,238 0.40 The following table summarizes information about stock options outstanding and exercisable as of March 31, 2020 : Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted-average Weighted-average Number Weighted-average (in thousands) (in years) (per share) (in thousands) (per share) $29.07–$40.00 81 1.47 $ 37.70 81 $ 37.70 $40.01–$60.00 224 2.41 $ 49.15 224 $ 49.15 $60.01–$80.00 116 4.03 $ 74.89 112 $ 74.89 $80.01–$100.00 1,393 5.99 $ 89.44 1,085 $ 90.01 $100.01–$120.00 182 4.88 $ 109.25 180 $ 109.18 $120.01–$140.00 402 5.44 $ 129.59 400 $ 129.61 $140.01–$160.00 954 7.86 $ 155.50 436 $ 155.41 $160.01–$180.00 669 8.24 $ 168.21 245 $ 165.11 $180.01–$189.38 1,498 8.65 $ 185.44 440 $ 185.31 Total 5,519 6.98 $ 137.34 3,203 $ 119.05 Share repurchase programs During 2018, the Company’s Board of Directors approved a share repurchase program (the “2018 Share Repurchase Program”), pursuant to which the Company repurchased $500.0 million of its common stock in 2018 and 2019. During the three months ended March 31, 2019 , the Company repurchased 537,018 of its common stock under the share repurchase program for an aggregate of $98.0 million including commissions and fees. As of June 30, 2019, the Company had repurchased the entire $500.0 million it was authorized to repurchase of its common stock under the 2018 Share Repurchase Program. During 2019, the Company’s Board of Directors approved a new share repurchase program (the “2019 Share Repurchase Program”), pursuant to which the Company is authorized to repurchase up to $500.0 million of its common stock between August 1, 2019 and December 31, 2020. The Company expects to fund further repurchases of its common stock through a combination of cash on hand and cash generated by operations. During the three months ended March 31, 2020 , the Company repurchased 1,403,868 shares of its common stock under the 2019 Share Repurchase Program for an aggregate of $300.0 million including commissions and fees. As of March 31, 2020 , there was a total of $164.0 million remaining for repurchases under the 2019 Share Repurchase Program.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is subject to U.S. federal, state, and foreign income taxes. For the three months ended March 31, 2020 and 2019 , the Company recorded provisions for income taxes of $54.8 million and $51.5 million , respectively. The Company’s effective tax rate for the three months ended March 31, 2020 was lower than the U.S. statutory rate primarily due to a discrete benefit related to the write-off of a long-term intercompany receivable and excess tax benefits related to stock-based compensation. The Company’s effective tax rate for the three months ended March 31, 2019 was lower than the U.S. statutory rate primarily due to excess tax benefits related to stock-based compensation. The Company released its valuation allowance on the majority of its net operating losses and other deferred tax assets as of December 31, 2018. Starting in 2019, the Company began recording a provision for income taxes on its pre-tax income using an effective tax rate approximating statutory rates. Due to the Company's ability to offset its pre-tax income against previously benefited net operating losses, it expects a portion of its tax provision to represent a non-cash expense until its net operating losses have been fully utilized. The Company maintained a valuation allowance of $205.2 million related primarily to U.S. state and foreign tax attributes as of December 31, 2019. On a periodic basis, the Company reassesses any valuation allowances that it maintains on its deferred tax assets, weighing positive and negative evidence to assess the recoverability of the deferred tax assets. In March 2020, the Coronavirus Aid, Relief and Economic Security Act (“the CARES Act”) was signed into law. The CARES Act includes provisions relating to several aspects of corporate income taxes. The Company does not currently expect the CARES Act to have a significant impact on its provision for income taxes; however, it will continue to monitor the provisions of the CARES Act in relation to its operations. The Company has reviewed the tax positions taken, or to be taken, in its tax returns for all tax years currently open to examination by a taxing authority. Unrecognized tax benefits represent the aggregate tax effect of differences between tax return positions and the benefits recognized in the financial statements. As of March 31, 2020 and December 31, 2019 , the Company had $43.0 million and $33.9 million , respectively, of gross unrecognized tax benefits, which would affect the Company’s tax rate if recognized. The Company does not expect that its unrecognized tax benefits will materially increase within the next twelve months. The Company accrues interest and penalties related to unrecognized tax benefits as a component of its provision for income taxes. As of March 31, 2020 , no significant interest or penalties were accrued. The Company did not recognize any material interest or penalties related to uncertain tax positions during the three months ended March 31, 2020 and 2019 . As of March 31, 2020 , foreign earnings, which were not significant, have been retained by foreign subsidiaries for indefinite reinvestment. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company could be subject to withholding taxes payable to the various foreign countries.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Revolving Credit Facility In September 2019, the Company and certain of its subsidiaries entered into a Credit Agreement (the “2019 Credit Agreement”) with Bank of America, N.A., as administrative agent and the lenders referred to therein. The 2019 Credit Agreement provides for a $500.0 million unsecured revolving facility, which was not drawn upon at closing. Amounts drawn pursuant to the 2019 Credit Agreement, if any, may be used to finance the Company’s working capital needs, and for general corporate or other lawful purposes. The Company had no borrowings outstanding under the 2019 Credit Agreement as of March 31, 2020 and December 31, 2019 . The 2019 Credit Agreement also provides that, subject to satisfaction of certain conditions, the Company may request that the borrowing capacity under the 2019 Credit Agreement be increased by an additional $500.0 million . The 2019 Credit Agreement, which matures on September 17, 2024, supersedes the Company’s credit agreement entered into in 2016 with Bank of America, N.A serving in the same capacity. Additionally, the 2019 Credit Agreement provides a sublimit of $50.0 million for letters of credit. Direct costs related to the 2019 Credit Agreement, which were not material to the Company’s financial statements, were deferred and will be recorded over the term of the 2019 Credit Agreement. Any amounts borrowed under the 2019 Credit Agreement will bear interest, at the Company’s option, at either a base rate or a Eurocurrency rate, in each case plus an applicable margin. Under the 2019 Credit Agreement, the applicable margins on base rate loans range from 0.125% to 0.50% and the applicable margins on Eurocurrency loans range from 1.125% to 1.50% , in each case based on the Company’s consolidated leverage ratio (the ratio of the Company’s total consolidated funded indebtedness to the Company’s consolidated EBITDA for the most recently completed four fiscal quarter period). Any amounts borrowed pursuant to the 2019 Credit Agreement are guaranteed by certain of the Company’s existing and future domestic subsidiaries, subject to certain exceptions. The 2019 Credit Agreement contains customary representations and warranties and affirmative and negative covenants, including financial covenants to maintain (i) subject to certain limited exceptions, a consolidated leverage ratio of 3.50 to 1.00 , subject to an increase to 4.00 to 1.00 following a material acquisition and (ii) a consolidated interest coverage ratio (the ratio of the Company’s consolidated EBITDA to its consolidated interest expenses for the most recently completed four fiscal quarter period) of 2.50 to 1.00 , in each case measured on a quarterly basis. The 2019 Credit Agreement also contains customary events of default. In the case of a continuing event of default, the administrative agent would be entitled to exercise various remedies, including the acceleration of amounts due under outstanding loans. As of March 31, 2020 , the Company was in compliance with the covenants described above. Guaranties and Indemnifications As permitted under Massachusetts law, the Company’s Articles of Organization and By-laws provide that the Company will indemnify certain of its officers and directors for certain claims asserted against them in connection with their service as an officer or director. The maximum potential amount of future payments that the Company could be required to make under these indemnification provisions is unlimited. However, the Company has purchased directors’ and officers’ liability insurance policies that could reduce its monetary exposure and enable it to recover a portion of any future amounts paid. No indemnification claims currently are outstanding, and the Company believes the estimated fair value of these indemnification arrangements is minimal. The Company customarily agrees in the ordinary course of its business to indemnification provisions in agreements with clinical trial investigators and sites in its drug development programs, sponsored research agreements with academic and not-for-profit institutions, various comparable agreements involving parties performing services for the Company and its real estate leases. The Company also customarily agrees to certain indemnification provisions in its drug discovery, development and commercialization collaboration agreements. With respect to the Company’s clinical trials and sponsored research agreements, these indemnification provisions typically apply to any claim asserted against the investigator or the investigator’s institution relating to personal injury or property damage, violations of law or certain breaches of the Company’s contractual obligations arising out of the research or clinical testing of the Company’s compounds or drug candidates. With respect to lease agreements, the indemnification provisions typically apply to claims asserted against the landlord relating to personal injury or property damage caused by the Company, to violations of law by the Company or to certain breaches of the Company’s contractual obligations. The indemnification provisions appearing in the Company’s collaboration agreements are similar to those for the other agreements discussed above, but in addition provide some limited indemnification for its collaborator in the event of third-party claims alleging infringement of intellectual property rights. In each of the cases above, the indemnification obligation generally survives the termination of the agreement for some extended period, although the Company believes the obligation typically has the most relevance during the contract term and for a short period of time thereafter. The maximum potential amount of future payments that the Company could be required to make under these provisions is generally unlimited. The Company has purchased insurance policies covering personal injury, property damage and general liability that reduce its exposure for indemnification and would enable it in many cases to recover all or a portion of any future amounts paid. The Company has never paid any material amounts to defend lawsuits or settle claims related to these indemnification provisions. Accordingly, the Company believes the estimated fair value of these indemnification arrangements is minimal. Other Contingencies The Company has certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a reserve for contingent liabilities when it is probable that future expenditures will be made, and such expenditures can be reasonably estimated. There were no material contingent liabilities accrued as of March 31, 2020 or December 31, 2019 .

Additional Cash Flow Informatio

Additional Cash Flow Information	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Additional Cash Flow Information	Additional Cash Flow Information The cash, cash equivalents and restricted cash at the beginning and ending of each period presented in the Company’s condensed consolidated statements of cash flows consisted of the following: Three Months Ended March 31, 2020 2019 Beginning of period End of period Beginning of period End of period (in thousands) Cash and cash equivalents $ 3,109,322 $ 3,593,412 $ 2,650,134 $ 2,893,885 Prepaid expenses and other current assets 8,004 8,552 4,910 6,250 Other assets 3,355 — 3,209 1,397 Cash, cash equivalents and restricted cash per statement of cash flows $ 3,120,681 $ 3,601,964 $ 2,658,253 $ 2,901,532

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements are unaudited and have been prepared by Vertex Pharmaceuticals Incorporated (“Vertex” or the “Company”) in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The condensed consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiaries. All material intercompany balances and transactions have been eliminated. The Company operates in one segment, pharmaceuticals. The Company has reclassified certain items from the prior year’s condensed consolidated financial statements to conform to the current year’s presentation. Certain information and footnote disclosures normally included in the Company’s 2019 Annual Report on Form 10-K have been condensed or omitted. These interim financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the financial position and results of operations for the interim periods ended March 31, 2020 and 2019 . The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full fiscal year. These interim financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2019 , which are contained in the Company’s 2019 Annual Report on Form 10-K.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the amounts of revenues and expenses during the reported periods. Significant estimates in these condensed consolidated financial statements have been made in connection with (i) determining the transaction price of revenues and (ii) accounting for intangible assets and contingent consideration. The Company bases its estimates on historical experience and various other assumptions, including in certain circumstances future projections that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.
Recently Adopted Accounting Standards and Recently Issued Accounting Standards	Recently Adopted Accounting Standards Leases On January 1, 2019, the Company adopted Accounting Standards Codification (“ASC”) 842, Leases (“ASC 842”) using the modified-retrospective method, which amended a number of aspects of lease accounting and required the Company to recognize right-of-use assets and liabilities on the balance sheet. As of January 1, 2019, the Company recorded a cumulative effect adjustment to increase its “ Accumulated deficit ” by $40.3 million , which related to its leases that were accounted for as build-to-suit leases under the previous accounting guidance. Internal-Use Software In 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”), which clarifies the accounting for implementation costs in cloud computing arrangements. ASU 2018-15 became effective on January 1, 2020. The adoption of ASU 2018-15 resulted in an insignificant amount of additional assets recorded on the Company’s condensed consolidated balance sheet. Fair Value Measurement In 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which modifies the disclosure requirements for fair value measurements. ASU 2018-13 became effective on January 1, 2020. The adoption of ASU 2018-13 resulted in additional disclosures related to the Company’s Level 3 inputs. Please refer to Note E, “Fair Value Measurements,” for further information. Credit Losses In 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires entities to record expected credit losses for certain financial instruments, including trade receivables, as an allowance that reflects the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities in unrealized loss positions, ASU 2016-13 requires allowances to be recorded instead of reducing the amortized cost of the investment. ASU 2016-13 became effective on January 1, 2020. The adoption of ASU 2016-13 did not have a significant impact on its condensed consolidated financial statements. Recently Issued Accounting Standards Income Taxes In 2019, the FASB issued ASU 2019-12 , Income Taxes (Topic 740) (“ ASU 2019-12 ”), which simplifies the accounting for income taxes. ASU 2019-12 is effective on January 1, 2021. The Company is evaluating the impact the adoption of ASU 2019-12 may have on its condensed consolidated financial statements. For a discussion of other recent accounting pronouncements please refer to Note A, “Nature of Business and Accounting Policies,” in the Company’s 2019 Annual Report on Form 10-K. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note A, “Nature of Business and Accounting Policies,” in its 2019

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	Product revenues, net consisted of the following: Three Months Ended March 31, 2020 2019 (in thousands) TRIKAFTA $ 895,233 $ — SYMDEKO/SYMKEVI 173,159 320,275 ORKAMBI 234,138 293,007 KALYDECO 212,577 243,971 Total product revenues, net * $ 1,515,107 $ 857,253 * The preceding table does not include collaborative and royalty revenues. Three Months Ended March 31, 2020 2019 (in thousands) United States $ 1,187,588 $ 641,104 Outside of the United States Europe 257,391 167,751 Other 70,128 49,580 Total revenues outside of the United States 327,519 217,331 Total revenues $ 1,515,107 $ 858,435

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table sets forth the computation of basic and diluted net income per common share for the periods ended: Three Months Ended March 31, 2020 2019 (in thousands, except per share amounts) Net income $ 602,753 $ 268,631 Basic weighted-average common shares outstanding 259,815 255,695 Effect of potentially dilutive securities: Stock options 1,868 2,585 Restricted stock and restricted stock units (including PSUs) 1,801 1,870 Employee stock purchase program 31 25 Diluted weighted-average common shares outstanding 263,515 260,175 Basic net income per common share $ 2.32 $ 1.05 Diluted net income per common share $ 2.29 $ 1.03
Potential gross common equivalent shares	The Company did not include the securities in the following table in the computation of the net income per common share because the effect would have been anti-dilutive during each period: Three Months Ended March 31, 2020 2019 (in thousands) Stock options 879 2,837 Unvested restricted stock and restricted stock units (including PSUs) 430 6

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Financial assets subject to fair value measurements (excluding VIE cash and cash equivalents, which are recorded as Restricted cash and cash equivalents (VIE))	The following tables set forth the Company’s financial assets and liabilities subject to fair value measurements (and does not include $1.8 billion and $ 2.3 billion of cash as of March 31, 2020 and December 31, 2019 , respectively): Fair Value Measurements as of March 31, 2020 Fair Value Hierarchy Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 1,736,913 $ 1,736,913 $ — $ — Commercial paper 30,700 — 30,700 — Marketable securities: Corporate equity securities 165,178 145,465 19,713 — Government-sponsored enterprise securities 7,791 7,791 — — Corporate debt securities 305,051 — 305,051 — Commercial paper 118,964 — 118,964 — Prepaid expenses and other current assets: Foreign currency forward contracts 25,434 — 25,434 — Other assets: Foreign currency forward contracts 1,798 — 1,798 — Total financial assets $ 2,391,829 $ 1,890,169 $ 501,660 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (459 ) $ — $ (459 ) $ — Long-term contingent consideration (178,100 ) — — (178,100 ) Other long-term liabilities: Foreign currency forward contracts (637 ) — (637 ) — Total financial liabilities $ (179,196 ) $ — $ (1,096 ) $ (178,100 ) Fair Value Measurements as of December 31, 2019 Fair Value Hierarchy Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 791,039 $ 791,039 $ — $ — Corporate debt securities 6,070 — 6,070 — Commercial paper 29,472 — 29,472 — Marketable securities: Corporate equity securities 282,084 261,797 20,287 — Government-sponsored enterprise securities 12,733 12,733 — — Corporate debt securities 301,799 — 301,799 — Commercial paper 102,356 — 102,356 — Prepaid expenses and other current assets: Foreign currency forward contracts 9,725 — 9,725 — Total financial assets $ 1,535,278 $ 1,065,569 $ 469,709 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (5,533 ) $ — $ (5,533 ) $ — Long-term contingent consideration (176,500 ) — — (176,500 ) Other long-term liabilities: Foreign currency forward contracts (1,821 ) — (1,821 ) — Total financial liabilities $ (183,854 ) $ — $ (7,354 ) $ (176,500 )
Schedule of fair value of our contingent consideration liabilities	The following table represents a rollforward of the fair value of the Company’s contingent consideration liabilities: Three Months Ended March 31, 2020 (in thousands) Balance at December 31, 2019 $ 176,500 Increase in fair value of contingent payments 1,600 Balance at March 31, 2020 $ 178,100

Marketable Securities and Equ_2

Marketable Securities and Equity Investments (Tables)	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Summary of cash equivalents and marketable securities	A summary of the Company’s cash equivalents and marketable securities, which are recorded at fair value (and do not include $1.8 billion and $ 2.3 billion of cash as of March 31, 2020 and December 31, 2019 , respectively), is shown below: Amortized Cost Gross Gross Fair Value (in thousands) As of March 31, 2020 Cash equivalents: Money market funds $ 1,736,913 $ — $ — $ 1,736,913 Commercial paper 30,700 4 (4 ) 30,700 Total cash equivalents 1,767,613 4 (4 ) 1,767,613 Marketable securities: Government-sponsored enterprise securities 7,717 74 — 7,791 Corporate debt securities 305,808 255 (1,012 ) 305,051 Commercial paper 118,542 426 (4 ) 118,964 Total marketable debt securities 432,067 755 (1,016 ) 431,806 Corporate equity securities 87,096 78,082 — 165,178 Total marketable securities $ 519,163 $ 78,837 $ (1,016 ) $ 596,984 As of December 31, 2019 Cash equivalents: Money market funds $ 791,039 $ — $ — $ 791,039 Corporate debt securities 6,070 — — 6,070 Commercial paper 29,470 3 (1 ) 29,472 Total cash equivalents 826,579 3 (1 ) 826,581 Marketable securities: Government-sponsored enterprise securities 12,689 44 — 12,733 Corporate debt securities 301,458 391 (50 ) 301,799 Commercial paper 102,240 121 (5 ) 102,356 Total marketable debt securities 416,387 556 (55 ) 416,888 Corporate equity securities 113,829 168,255 — 282,084 Total marketable securities $ 530,216 $ 168,811 $ (55 ) $ 698,972 Available-for-sale debt securities were classified on the Company's condensed consolidated balance sheets at fair value as follows: As of March 31, 2020 As of December 31, 2019 (in thousands) Cash and cash equivalents $ 1,767,613 $ 826,581 Marketable securities 431,806 416,888 Total $ 2,199,419 $ 1,243,469 Available-for-sale debt securities by contractual maturity were as follows: As of March 31, 2020 As of December 31, 2019 (in thousands) Matures within one year $ 2,157,586 $ 1,137,942 Matures after one year through five years 41,833 105,527 Total $ 2,199,419 $ 1,243,469

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated other comprehensive income (loss) by component: Unrealized Holding Gains (Losses), Net of Tax Foreign Currency Translation Adjustment On Available-For-Sale Debt Securities On Foreign Currency Forward Contracts Total (in thousands) Balance at December 31, 2019 $ (895 ) $ 503 $ (1,581 ) $ (1,973 ) Other comprehensive (loss) income before reclassifications (2,662 ) (764 ) 25,772 22,346 Amounts reclassified from accumulated other comprehensive income (loss) — — (6,990 ) (6,990 ) Net current period other comprehensive (loss) income (2,662 ) (764 ) 18,782 15,356 Balance at March 31, 2020 $ (3,557 ) $ (261 ) $ 17,201 $ 13,383 Balance at December 31, 2018 $ (11,227 ) $ (536 ) $ 12,422 $ 659 Other comprehensive income before reclassifications 4,967 596 5,126 10,689 Amounts reclassified from accumulated other comprehensive income — — (5,348 ) (5,348 ) Net current period other comprehensive income (loss) 4,967 596 (222 ) 5,341 Balance at March 31, 2019 $ (6,260 ) $ 60 $ 12,200 $ 6,000

Hedging (Tables)

Hedging (Tables)	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Cash Flow Hedging Instruments	The following table summarizes the notional amount of the Company’s outstanding foreign currency forward contracts designated as cash flow hedges under GAAP: As of March 31, 2020 As of December 31, 2019 Foreign Currency (in thousands) Euro $ 581,764 $ 501,197 British pound sterling 124,160 87,032 Australian dollar 74,643 89,705 Canadian dollar 46,390 50,452 Total foreign currency forward contracts $ 826,957 $ 728,386
Schedule of Foreign Exchange Contracts, Condensed Consolidated Statements of Operations	During the three months ended March 31, 2020 and 2019 , the Company recognized the following related to foreign currency forward contacts in its condensed consolidated statements of operations: Three Months Ended March 31, 2020 2019 (in thousands) Designated as hedging instruments - Reclassified from AOCI Product revenues, net $ 8,922 $ 6,839 Not designated as hedging instruments Other (expense) income, net $ 16,229 $ 3,151 Total reported in the Condensed Consolidated Statement of Operations Product revenues, net $ 1,515,107 $ 857,253 Other (expense) income, net $ (61,130 ) $ 42,610
Schedule of Foreign Exchange Contracts	The following table summarizes the fair value of the Company’s outstanding foreign currency forward contracts designated as cash flow hedges under GAAP included on its condensed consolidated balance sheets: As of March 31, 2020 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 25,434 Other current liabilities $ (459 ) Other assets 1,798 Other long-term liabilities (637 ) Total assets $ 27,232 Total liabilities $ (1,096 ) As of December 31, 2019 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 9,725 Other current liabilities $ (5,533 ) Other assets — Other long-term liabilities (1,821 ) Total assets $ 9,725 Total liabilities $ (7,354 )
Offsetting liabilities	The following table summarizes the potential effect of offsetting derivatives by type of financial instrument designated as cash flow hedges under GAAP on the Company’s condensed consolidated balance sheets: As of March 31, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 27,232 $ — $ 27,232 $ (1,096 ) $ 26,136 Total liabilities (1,096 ) — (1,096 ) 1,096 — As of December 31, 2019 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 9,725 $ — $ 9,725 $ (7,354 ) $ 2,371 Total liabilities (7,354 ) — (7,354 ) 7,354 —
Offsetting assets	The following table summarizes the potential effect of offsetting derivatives by type of financial instrument designated as cash flow hedges under GAAP on the Company’s condensed consolidated balance sheets: As of March 31, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 27,232 $ — $ 27,232 $ (1,096 ) $ 26,136 Total liabilities (1,096 ) — (1,096 ) 1,096 — As of December 31, 2019 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 9,725 $ — $ 9,725 $ (7,354 ) $ 2,371 Total liabilities (7,354 ) — (7,354 ) 7,354 —

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories by Type	Inventories consisted of the following: As of March 31, 2020 As of December 31, 2019 (in thousands) Raw materials $ 24,835 $ 26,247 Work-in-process 117,427 107,021 Finished goods 44,825 34,234 Total $ 187,087 $ 167,502

Stock-based Compensation Expe_2

Stock-based Compensation Expense and Share Repurchase Programs (Tables)	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-based compensation expense by line item	During the three months ended March 31, 2020 and 2019 , the Company recognized the following stock-based compensation expense: Three Months Ended March 31, 2020 2019 (in thousands) Stock-based compensation expense by type of award: Restricted stock and restricted stock units (including PSUs) $ 97,149 $ 63,510 Stock options 17,266 28,156 ESPP share issuances 2,485 2,577 Stock-based compensation expense related to inventories (1,194 ) (452 ) Total stock-based compensation expense included in costs and expenses $ 115,706 $ 93,791 Stock-based compensation expense by line item: Cost of sales $ 1,361 $ 1,338 Research and development expenses 72,687 59,715 Sales, general and administrative expenses 41,658 32,738 Total stock-based compensation expense included in costs and expenses 115,706 93,791 Income tax effect (64,246 ) (39,524 ) Total stock-based compensation expense, net of tax $ 51,460 $ 54,267
Unrecognized stock-based compensation expense, net of estimated forfeitures	The following table sets forth the Company’s unrecognized stock-based compensation expense as of March 31, 2020 , by type of award and the weighted-average period over which that expense is expected to be recognized: As of March 31, 2020 Unrecognized Expense Weighted-average (in thousands) (in years) Type of award: Restricted stock and restricted stock units (including PSUs) $ 550,095 2.27 Stock options $ 109,086 2.33 ESPP share issuances $ 2,238 0.40
Stock options outstanding and exercisable	The following table summarizes information about stock options outstanding and exercisable as of March 31, 2020 : Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted-average Weighted-average Number Weighted-average (in thousands) (in years) (per share) (in thousands) (per share) $29.07–$40.00 81 1.47 $ 37.70 81 $ 37.70 $40.01–$60.00 224 2.41 $ 49.15 224 $ 49.15 $60.01–$80.00 116 4.03 $ 74.89 112 $ 74.89 $80.01–$100.00 1,393 5.99 $ 89.44 1,085 $ 90.01 $100.01–$120.00 182 4.88 $ 109.25 180 $ 109.18 $120.01–$140.00 402 5.44 $ 129.59 400 $ 129.61 $140.01–$160.00 954 7.86 $ 155.50 436 $ 155.41 $160.01–$180.00 669 8.24 $ 168.21 245 $ 165.11 $180.01–$189.38 1,498 8.65 $ 185.44 440 $ 185.31 Total 5,519 6.98 $ 137.34 3,203 $ 119.05

Additional Cash Flow Informat_2

Additional Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Cash Flow Statement	The cash, cash equivalents and restricted cash at the beginning and ending of each period presented in the Company’s condensed consolidated statements of cash flows consisted of the following: Three Months Ended March 31, 2020 2019 Beginning of period End of period Beginning of period End of period (in thousands) Cash and cash equivalents $ 3,109,322 $ 3,593,412 $ 2,650,134 $ 2,893,885 Prepaid expenses and other current assets 8,004 8,552 4,910 6,250 Other assets 3,355 — 3,209 1,397 Cash, cash equivalents and restricted cash per statement of cash flows $ 3,120,681 $ 3,601,964 $ 2,658,253 $ 2,901,532

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020segment	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment	1
Cumulative effect adjustment to accumulated deficit		$ (40,310)
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment to accumulated deficit		(40,310)
Accounting Standards Update 2016-02 | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment to accumulated deficit		$ (40,300)

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 1,515,107	$ 858,435
United States
Disaggregation of Revenue [Line Items]
Revenues	1,187,588	641,104
Europe
Disaggregation of Revenue [Line Items]
Revenues	257,391	167,751
Other
Disaggregation of Revenue [Line Items]
Revenues	70,128	49,580
Total revenues outside of the United States
Disaggregation of Revenue [Line Items]
Revenues	327,519	217,331
Product revenues, net
Disaggregation of Revenue [Line Items]
Revenues	1,515,107	857,253
TRIKAFTA
Disaggregation of Revenue [Line Items]
Revenues	895,233	0
SYMDEKO/SYMKEVI
Disaggregation of Revenue [Line Items]
Revenues	173,159	320,275
ORKAMBI
Disaggregation of Revenue [Line Items]
Revenues	234,138	293,007
KALYDECO
Disaggregation of Revenue [Line Items]
Revenues	$ 212,577	$ 243,971

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract liabilities	$ 76.3	$ 62.3

Collaborative Arrangements (Det

Collaborative Arrangements (Details)	3 Months Ended
	Mar. 31, 2020USD ($)	Dec. 31, 2019target	Mar. 31, 2019USD ($)
CRISPR Therapeutics
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, right to exclusively license, number of targets | target		3
Collaborative arrangement, development and regulatory potential milestone payments maximum	$ 410,000,000
CTX001 Co-Co
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement research and development expenses	9,300,000		$ 7,000,000
CRISPR DMD/DM1
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, development and regulatory potential milestone payments maximum	800,000,000
Collaborative arrangement research and development expenses	$ 25,000,000

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Computation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income	$ 602,753	$ 268,631
Basic weighted-average common shares outstanding (in shares)	259,815	255,695
Effect of potentially dilutive securities:
Employee stock purchase program (in shares)	31	25
Diluted weighted-average common shares outstanding (in shares)	263,515	260,175
Basic net income per common share (in dollars per share)	$ 2.32	$ 1.05
Diluted net income per common share (in dollars per share)	$ 2.29	$ 1.03
Stock options
Effect of potentially dilutive securities:
Share-based payment arrangements (in shares)	1,868	2,585
Unvested restricted stock and restricted stock units (including PSUs)
Effect of potentially dilutive securities:
Share-based payment arrangements (in shares)	1,801	1,870

Earnings Per Share - Anti-dilut

Earnings Per Share - Anti-dilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	879	2,837
Unvested restricted stock and restricted stock units (including PSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	430	6

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Subject to Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Cash	$ 1,800,000	$ 2,300,000
Financial instruments carried at fair value (liability positions):
Long-term contingent consideration	(178,100)	(176,500)
Recurring basis
Financial instruments carried at fair value (asset positions):
Derivative asset current	25,434	9,725
Derivative asset noncurrent	1,798
Total financial assets	2,391,829	1,535,278
Financial instruments carried at fair value (liability positions):
Derivative liability current	(459)	(5,533)
Long-term contingent consideration	(178,100)	(176,500)
Derivative liability, noncurrent	(637)	(1,821)
Total financial liabilities	(179,196)	(183,854)
Recurring basis | Level 1
Financial instruments carried at fair value (asset positions):
Derivative asset current	0	0
Derivative asset noncurrent	0
Total financial assets	1,890,169	1,065,569
Financial instruments carried at fair value (liability positions):
Derivative liability current	0	0
Long-term contingent consideration	0	0
Derivative liability, noncurrent	0	0
Total financial liabilities	0	0
Recurring basis | Level 2
Financial instruments carried at fair value (asset positions):
Derivative asset current	25,434	9,725
Derivative asset noncurrent	1,798
Total financial assets	501,660	469,709
Financial instruments carried at fair value (liability positions):
Derivative liability current	(459)	(5,533)
Long-term contingent consideration	0	0
Derivative liability, noncurrent	(637)	(1,821)
Total financial liabilities	(1,096)	(7,354)
Recurring basis | Level 3
Financial instruments carried at fair value (asset positions):
Derivative asset current	0	0
Derivative asset noncurrent	0
Total financial assets	0	0
Financial instruments carried at fair value (liability positions):
Derivative liability current	0	0
Long-term contingent consideration	(178,100)	(176,500)
Derivative liability, noncurrent	0	0
Total financial liabilities	(178,100)	(176,500)
Recurring basis | Money market funds
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	1,736,913	791,039
Recurring basis | Money market funds | Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	1,736,913	791,039
Recurring basis | Money market funds | Level 2
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Recurring basis | Money market funds | Level 3
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Recurring basis | Government-sponsored enterprise securities
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents		6,070
Marketable securities	7,791	12,733
Recurring basis | Government-sponsored enterprise securities | Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents		0
Marketable securities	7,791	12,733
Recurring basis | Government-sponsored enterprise securities | Level 2
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents		6,070
Marketable securities	0	0
Recurring basis | Government-sponsored enterprise securities | Level 3
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents		0
Marketable securities	0	0
Recurring basis | Commercial paper
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	30,700	29,472
Marketable securities	118,964	102,356
Recurring basis | Commercial paper | Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Marketable securities	0	0
Recurring basis | Commercial paper | Level 2
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	30,700	29,472
Marketable securities	118,964	102,356
Recurring basis | Commercial paper | Level 3
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Marketable securities	0	0
Recurring basis | Corporate equity securities
Financial instruments carried at fair value (asset positions):
Marketable securities	165,178	282,084
Recurring basis | Corporate equity securities | Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	145,465	261,797
Recurring basis | Corporate equity securities | Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	19,713	20,287
Recurring basis | Corporate equity securities | Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring basis | Corporate debt securities
Financial instruments carried at fair value (asset positions):
Marketable securities	305,051	301,799
Recurring basis | Corporate debt securities | Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring basis | Corporate debt securities | Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	305,051	301,799
Recurring basis | Corporate debt securities | Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - Level 3 $ in Millions	Mar. 31, 2020USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Remaining milestone payment	$ 678.3
Minimum | Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, measurement input	0.018
Maximum | Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, measurement input	0.031

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Contingent Consideration Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at December 31, 2019	$ 176,500
Increase in fair value of contingent payments	1,600	$ 0
Balance at March 31, 2020	$ 178,100

Marketable Securities and Equ_3

Marketable Securities and Equity Investments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Summary of cash, cash equivalents and marketable securities
Cash	$ 1,800,000,000		$ 2,300,000,000
Other-than-temporary declines in fair value of available-for-sale debt securities	0	$ 0
Fair value	165,178,000		282,084,000
Unrealized gain (loss)	(39,400,000)	$ 43,600,000
Equity Securities, Cost Basis	87,096,000		113,829,000
Other assets
Summary of cash, cash equivalents and marketable securities
Equity securities without readily determinable fair value, amount	46,600,000
Corporate equity securities
Summary of cash, cash equivalents and marketable securities
Fair value	165,200,000		$ 282,100,000
CRISPR Sale [Member]
Summary of cash, cash equivalents and marketable securities
Proceeds from Sale and Maturity of Marketable Securities	72,000,000
Equity Securities, Cost Basis	$ 26,700,000

Marketable Securities and Equ_4

Marketable Securities and Equity Investments - Summary of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Total marketable debt securities
Fair Value	$ 2,199,419	$ 1,243,469
Corporate equity securities
Amortized Cost	87,096	113,829
Gross Unrealized Gains	78,082	168,255
Gross Unrealized Losses	0	0
Fair Value	165,178	282,084
Amortized Cost	519,163	530,216
Gross Unrealized Gains	78,837	168,811
Gross Unrealized Losses	(1,016)	(55)
Fair Value	596,984	698,972
Cash equivalents
Total marketable debt securities
Amortized Cost	1,767,613	826,579
Gross Unrealized Gains	4	3
Gross Unrealized Losses	(4)	(1)
Fair Value	1,767,613	826,581
Cash equivalents | Money market funds
Total marketable debt securities
Amortized Cost	1,736,913	791,039
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	1,736,913	791,039
Cash equivalents | Commercial paper
Total marketable debt securities
Amortized Cost	30,700	29,470
Gross Unrealized Gains	4	3
Gross Unrealized Losses	(4)	(1)
Fair Value	30,700	29,472
Cash equivalents | Corporate debt securities
Total marketable debt securities
Amortized Cost		6,070
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		6,070
Marketable securities
Total marketable debt securities
Amortized Cost	432,067	416,387
Gross Unrealized Gains	755	556
Gross Unrealized Losses	(1,016)	(55)
Fair Value	431,806	416,888
Marketable securities | Government-sponsored enterprise securities
Total marketable debt securities
Amortized Cost	7,717	12,689
Gross Unrealized Gains	74	44
Gross Unrealized Losses	0	0
Fair Value	7,791	12,733
Marketable securities | Corporate debt securities
Total marketable debt securities
Amortized Cost	305,808	301,458
Gross Unrealized Gains	255	391
Gross Unrealized Losses	(1,012)	(50)
Fair Value	305,051	301,799
Marketable securities | Commercial paper
Total marketable debt securities
Amortized Cost	118,542	102,240
Gross Unrealized Gains	426	121
Gross Unrealized Losses	(4)	(5)
Fair Value	$ 118,964	$ 102,356

Marketable Securities and Equ_5

Marketable Securities and Equity Investments - Available-for-Sale Debt Securities at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt securities	$ 2,199,419	$ 1,243,469
Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Debt securities	1,767,613	826,581
Marketable securities
Debt Securities, Available-for-sale [Line Items]
Debt securities	$ 431,806	$ 416,888

Marketable Securities and Equ_6

Marketable Securities and Equity Investments - Available-for-Sale Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Matures within one year	$ 2,157,586	$ 1,137,942
Matures after one year through five years	41,833	105,527
Total	$ 2,199,419	$ 1,243,469

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 6,085,244	$ 4,435,203
Other comprehensive (loss) income before reclassifications	22,346	10,689
Amounts reclassified from accumulated other comprehensive income (loss)	(6,990)	(5,348)
Total changes in other comprehensive income	15,356	5,341
Ending Balance	6,461,654	4,723,313
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(895)	(11,227)
Other comprehensive (loss) income before reclassifications	(2,662)	4,967
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total changes in other comprehensive income	(2,662)	4,967
Ending Balance	(3,557)	(6,260)
On Available-For-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	503	(536)
Other comprehensive (loss) income before reclassifications	(764)	596
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total changes in other comprehensive income	(764)	596
Ending Balance	(261)	60
On Foreign Currency Forward Contracts
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1,581)	12,422
Other comprehensive (loss) income before reclassifications	25,772	5,126
Amounts reclassified from accumulated other comprehensive income (loss)	(6,990)	(5,348)
Total changes in other comprehensive income	18,782	(222)
Ending Balance	17,201	12,200
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1,973)	659
Total changes in other comprehensive income	15,356	5,341
Ending Balance	$ 13,383	$ 6,000

Hedging - Narrative (Details)

Hedging - Narrative (Details) - Foreign currency forward contracts $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Not designated as hedging instruments
Derivative [Line Items]
Derivative term	1 month
Cash flow hedging | Not designated as hedging instruments
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 522.2
Cash flow hedging | Minimum
Derivative [Line Items]
Derivative term	1 month
Cash flow hedging | Maximum
Derivative [Line Items]
Derivative term	18 months

Hedging - Notional Amount (Deta

Hedging - Notional Amount (Details) - Foreign currency forward contracts - Designated as hedging instruments - Cash flow hedging - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 826,957	$ 728,386
Euro
Derivative [Line Items]
Notional amount of foreign currency forward contract	581,764	501,197
British pound sterling
Derivative [Line Items]
Notional amount of foreign currency forward contract	124,160	87,032
Australian dollar
Derivative [Line Items]
Notional amount of foreign currency forward contract	74,643	89,705
Canadian dollar
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 46,390	$ 50,452

Hedging - Cash Flow Hedging Ins

Hedging - Cash Flow Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	$ 1,515,107	$ 858,435
Other (expense) income	(61,130)	42,610
On Foreign Currency Forward Contracts | Reclassification out of Accumulated Other Comprehensive Income | Foreign currency forward contracts | Not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Other (expense) income	16,229	3,151
Product revenues, net
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	1,515,107	857,253
Product revenues, net | On Foreign Currency Forward Contracts | Reclassification out of Accumulated Other Comprehensive Income | Foreign currency forward contracts | Designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	$ 8,922	$ 6,839

Hedging - Derivative Fair Value

Hedging - Derivative Fair Value (Details) - Designated as hedging instruments - Foreign currency forward contracts - Cash flow hedging - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Total assets	$ 27,232	$ 9,725
Total liabilities	(1,096)	(7,354)
Prepaid expenses and other current assets
Derivative [Line Items]
Total assets	25,434	9,725
Other current liabilities
Derivative [Line Items]
Total liabilities	(459)	(5,533)
Other assets
Derivative [Line Items]
Total assets	1,798	0
Other long-term liabilities
Derivative [Line Items]
Total liabilities	$ (637)	$ (1,821)

Hedging - Offsetting Derivative

Hedging - Offsetting Derivatives (Details) - Cash flow hedging - Designated as hedging instruments - Foreign currency forward contracts - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Offsetting Derivative Assets [Abstract]
Total assets	$ 27,232	$ 9,725
Gross Amounts Offset	0	0
Gross Amounts Presented	27,232	9,725
Gross Amounts Not Offset	(1,096)	(7,354)
Legal Offset	26,136	2,371
Offsetting Derivative Liabilities [Abstract]
Gross Amounts Recognized	(1,096)	(7,354)
Gross Amounts Offset	0	0
Gross Amounts Presented	(1,096)	(7,354)
Gross Amounts Not Offset	1,096	7,354
Legal Offset	$ 0	$ 0

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 24,835	$ 26,247
Work-in-process	117,427	107,021
Finished goods	44,825	34,234
Total Inventories	$ 187,087	$ 167,502

Stock-based Compensation Expe_3

Stock-based Compensation Expense and Share Repurchase Programs - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	$ 115,706	$ 93,791
Stock-based compensation expense related to inventories	(1,194)	(452)
Share-based compensation expense by type of award	115,706	93,791
Income tax effect	(64,246)	(39,524)
Total stock-based compensation expense, net of tax	51,460	54,267
Cost of sales
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	1,361	1,338
Research and development expenses
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	72,687	59,715
Sales, general and administrative expenses
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	41,658	32,738
Unvested restricted stock and restricted stock units (including PSUs)
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	97,149	63,510
Type of award:
Unrecognized Expense	$ 550,095
Weighted-average Recognition Period	2 years 3 months 7 days
Stock options
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	$ 17,266	28,156
Type of award:
Unrecognized Expense	$ 109,086
Weighted-average Recognition Period	2 years 3 months 29 days
ESPP share issuances
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	$ 2,485	$ 2,577
Type of award:
Unrecognized Expense	$ 2,238
Weighted-average Recognition Period	12 days

Stock-based Compensation Expe_4

Stock-based Compensation Expense and Share Repurchase Programs - Stock Options Outstanding and Exercisable (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price range, options outstanding (in shares) | shares	5,519
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	6 years 11 months 23 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 137.34
Exercise price range, options exercisable (in shares) | shares	3,203
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 119.05
$29.07–$40.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	29.07
Exercise price, high end of range (in dollars per share)	$ 40
Exercise price range, options outstanding (in shares) | shares	81
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	1 year 5 months 19 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 37.70
Exercise price range, options exercisable (in shares) | shares	81
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 37.70
$40.01–$60.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	40.01
Exercise price, high end of range (in dollars per share)	$ 60
Exercise price range, options outstanding (in shares) | shares	224
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	2 years 4 months 28 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 49.15
Exercise price range, options exercisable (in shares) | shares	224
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 49.15
$60.01–$80.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	60.01
Exercise price, high end of range (in dollars per share)	$ 80
Exercise price range, options outstanding (in shares) | shares	116
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	4 years 10 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 74.89
Exercise price range, options exercisable (in shares) | shares	112
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 74.89
$80.01–$100.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	80.01
Exercise price, high end of range (in dollars per share)	$ 100
Exercise price range, options outstanding (in shares) | shares	1,393
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	5 years 11 months 26 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 89.44
Exercise price range, options exercisable (in shares) | shares	1,085
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 90.01
$100.01–$120.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	100.01
Exercise price, high end of range (in dollars per share)	$ 120
Exercise price range, options outstanding (in shares) | shares	182
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	4 years 10 months 17 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 109.25
Exercise price range, options exercisable (in shares) | shares	180
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 109.18
$120.01–$140.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	120.01
Exercise price, high end of range (in dollars per share)	$ 140
Exercise price range, options outstanding (in shares) | shares	402
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	5 years 5 months 8 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 129.59
Exercise price range, options exercisable (in shares) | shares	400
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 129.61
$140.01–$160.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	140.01
Exercise price, high end of range (in dollars per share)	$ 160
Exercise price range, options outstanding (in shares) | shares	954
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	7 years 10 months 9 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 155.50
Exercise price range, options exercisable (in shares) | shares	436
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 155.41
$160.01–$180.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	160.01
Exercise price, high end of range (in dollars per share)	$ 180
Exercise price range, options outstanding (in shares) | shares	669
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	8 years 2 months 26 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 168.21
Exercise price range, options exercisable (in shares) | shares	245
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 165.11
$180.01–$189.38
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	180.01
Exercise price, high end of range (in dollars per share)	$ 189.38
Exercise price range, options outstanding (in shares) | shares	1,498
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	8 years 7 months 24 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 185.44
Exercise price range, options exercisable (in shares) | shares	440
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 185.31

Stock-based Compensation Expe_5

Stock-based Compensation Expense and Share Repurchase Programs - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jul. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Amount of shares repurchased	$ 300,026,000	$ 98,007,000
Share Repurchase Program 2018
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be repurchased					$ 500,000,000
Shares repurchased (in shares)		537,018
Amount of shares repurchased		$ 98,000,000
Cumulative value of shares repurchased				$ 500,000,000
Share Repurchase Program 2019
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be repurchased			$ 500,000,000
Shares repurchased (in shares)	1,403,868
Amount of shares repurchased	$ 300,000,000
Stock repurchase program, remaining amount	$ 164,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 54,781	$ 51,534
Deferred tax assets, valuation allowance			$ 205,200
Unrecognized tax benefits	$ 43,000		$ 33,900

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Sep. 30, 2019
Line of Credit Facility [Line Items]
Indemnification claims	$ 0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity		$ 500,000,000
Line of credit facility additional borrowing capacity		500,000,000
Debt covenant, consolidated leverage ratio	3.50
Debt covenant, increase in consolidated leverage ratio	4
Debt covenant, interest coverage ratio	2.50
Revolving Credit Facility | Base Rate | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.125%
Revolving Credit Facility | Base Rate | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.50%
Revolving Credit Facility | Eurodollar | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.125%
Revolving Credit Facility | Eurodollar | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.50%
Letters of Credit
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity		$ 50,000,000

Additional Cash Flow Informat_3

Additional Cash Flow Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 3,593,412	$ 3,109,322	$ 2,893,885	$ 2,650,134
Cash, cash equivalents and restricted cash per statement of cash flows	3,601,964	3,120,681	2,901,532	2,658,253
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	8,552	8,004	6,250	4,910
Other assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	$ 0	$ 3,355	$ 1,397	$ 3,209