Vertex Pharmaceuticals (VRTX) 10-Q 30 Oct 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 23, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	000-19319
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		260,037,894
Entity Central Index Key	0000875320
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Revenues	$ 1,538,271	$ 949,828	$ 4,577,863	$ 2,749,556
Costs and expenses:
Cost of sales	186,182	131,914	533,199	362,746
Research and development expenses	493,497	555,948	1,362,953	1,274,529
Sales, general and administrative expenses	184,551	159,674	558,613	463,221
Change in fair value of contingent consideration	1,800	2,959	12,600	2,959
Total costs and expenses	866,030	850,495	2,467,365	2,103,455
Income from operations	672,241	99,333	2,110,498	646,101
Interest income	3,100	17,628	19,919	51,319
Interest expense	(13,856)	(14,548)	(41,863)	(44,253)
Other income (expense), net	84,386	(31,747)	139,621	64,802
Income before provision for income taxes	745,871	70,666	2,228,175	717,969
Provision for income taxes	78,437	13,148	120,718	124,393
Net income	$ 667,434	$ 57,518	$ 2,107,457	$ 593,576
Net income per common share:
Basic (in dollars per share)	$ 2.56	$ 0.22	$ 8.10	$ 2.32
Diluted (in dollars per share)	$ 2.53	$ 0.22	$ 7.98	$ 2.28
Shares used in per share calculations:
Basic (in shares)	260,392	256,946	260,313	256,289
Diluted (in shares)	264,079	260,473	264,031	260,182
Product revenues, net
Revenues:
Revenues	$ 1,536,271	$ 949,828	$ 4,575,863	$ 2,747,461
Collaborative and royalty revenues
Revenues:
Revenues	$ 2,000	$ 0	$ 2,000	$ 2,095

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 667,434	$ 57,518	$ 2,107,457	$ 593,576
Other comprehensive (loss) income:
Unrealized holding (losses) gains on marketable securities, net	(1,132)	64	818	1,111
Unrealized (losses) gains on foreign currency forward contracts, net of tax of $7.6 million, $2.2 million, $7.3 million and $5.5 million, respectively	(26,313)	12,812	(27,211)	6,814
Foreign currency translation adjustment	584	9,172	(12,616)	10,263
Total other comprehensive (loss) income	(26,861)	22,048	(39,009)	18,188
Comprehensive income	$ 640,573	$ 79,566	$ 2,068,448	$ 611,764

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Unrealized (losses) gains on foreign currency forward contracts, tax	$ 7.6	$ 2.2	$ 7.3	$ 5.5

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 5,358,087	$ 3,109,322
Marketable securities	792,971	698,972
Accounts receivable, net	791,917	633,518
Inventories	245,460	167,502
Prepaid expenses and other current assets	270,021	213,515
Total current assets	7,458,456	4,822,829
Property and equipment, net	920,913	745,080
Goodwill	1,002,158	1,002,158
Intangible assets	400,000	400,000
Deferred tax assets	1,147,816	1,190,815
Other assets	372,290	157,583
Total assets	11,301,633	8,318,465
Current liabilities:
Accounts payable	107,786	87,610
Accrued expenses	1,703,699	1,116,912
Other current liabilities	192,541	130,305
Total current liabilities	2,004,026	1,334,827
Long-term finance lease liabilities	546,514	538,576
Long-term contingent consideration	189,100	176,500
Other long-term liabilities	428,520	183,318
Total liabilities	3,168,160	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, 260,174 and 258,993 shares issued and outstanding, respectively	2,601	2,589
Additional paid-in capital	7,917,375	7,937,606
Accumulated other comprehensive loss	(40,982)	(1,973)
Retained earnings (accumulated deficit)	254,479	(1,852,978)
Total shareholders’ equity	8,133,473	6,085,244
Total liabilities and shareholders’ equity	$ 11,301,633	$ 8,318,465

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 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 (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	260,174,000	258,993,000
Common stock, shares outstanding (in shares)	260,174,000	258,993,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative effect adjustment for adoption of new accounting guidance	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit)Cumulative effect adjustment for adoption of new accounting guidance
Beginning balance (in shares) at Dec. 31, 2018			255,172
Beginning balance at Dec. 31, 2018	$ 4,435,203	$ (40,310)	$ 2,546	$ 7,421,476	$ 659	$ (2,989,478)	$ (40,310)
Increase (Decrease) in Stockholders' Equity
Other comprehensive income (loss), net of tax	18,188				18,188
Net income	593,576					593,576
Repurchases of common stock (in shares)			(904)
Repurchase of common stock	(162,018)		$ (9)	(162,009)
Common stock withheld for employee tax obligations (in shares)			(27)
Common stock withheld for employee tax obligations	(5,936)			(5,936)
Issuance of common stock under benefit plans (in shares)			3,024
Issuance of common stock under benefit plans	144,557		$ 34	144,523
Stock-based compensation expense	270,134			270,134
Ending balance (in shares) at Sep. 30, 2019			257,265
Ending balance at Sep. 30, 2019	5,253,394		$ 2,571	7,668,188	18,847	(2,436,212)
Beginning balance (in shares) at Jun. 30, 2019			256,671
Beginning balance at Jun. 30, 2019	5,069,965		$ 2,565	7,564,331	(3,201)	(2,493,730)
Increase (Decrease) in Stockholders' Equity
Other comprehensive income (loss), net of tax	22,048				22,048
Net income	57,518					57,518
Repurchases of common stock (in shares)			(71)
Repurchase of common stock	(12,001)			(12,001)
Common stock withheld for employee tax obligations	(104)			(104)
Issuance of common stock under benefit plans (in shares)			665
Issuance of common stock under benefit plans	30,012		$ 6	30,006
Stock-based compensation expense	85,956			85,956
Ending balance (in shares) at Sep. 30, 2019			257,265
Ending balance at Sep. 30, 2019	5,253,394		$ 2,571	7,668,188	18,847	(2,436,212)
Beginning balance (in 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 (loss), net of tax	(39,009)				(39,009)
Net income	2,107,457					2,107,457
Repurchases of common stock (in shares)			(1,807)
Repurchase of common stock	(408,033)		$ (18)	(408,015)
Common stock withheld for employee tax obligations (in shares)			(727)
Common stock withheld for employee tax obligations	(179,775)		$ (7)	(179,768)
Issuance of common stock under benefit plans (in shares)			3,715
Issuance of common stock under benefit plans	232,079		$ 37	232,042
Stock-based compensation expense	335,510			335,510
Ending balance (in shares) at Sep. 30, 2020			260,174
Ending balance at Sep. 30, 2020	8,133,473		$ 2,601	7,917,375	(40,982)	254,479
Beginning balance (in shares) at Jun. 30, 2020			260,124
Beginning balance at Jun. 30, 2020	7,519,242		$ 2,601	7,943,717	(14,121)	(412,955)
Increase (Decrease) in Stockholders' Equity
Other comprehensive income (loss), net of tax	(26,861)				(26,861)
Net income	667,434					667,434
Repurchases of common stock (in shares)			(403)
Repurchase of common stock	(108,007)		$ (4)	(108,003)
Common stock withheld for employee tax obligations (in shares)			(141)
Common stock withheld for employee tax obligations	(40,528)		$ (1)	(40,527)
Issuance of common stock under benefit plans (in shares)			594
Issuance of common stock under benefit plans	21,704		$ 5	21,699
Stock-based compensation expense	100,489			100,489
Ending balance (in shares) at Sep. 30, 2020			260,174
Ending balance at Sep. 30, 2020	$ 8,133,473		$ 2,601	$ 7,917,375	$ (40,982)	$ 254,479

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 2,107,457	$ 593,576
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	332,434	268,898
Depreciation expense	80,160	80,685
Increase in fair value of contingent consideration	12,600	2,959
Deferred income taxes	65,110	94,175
Gains on equity securities	(140,866)	(68,862)
Other non-cash items, net	52,371	(4,024)
Changes in operating assets and liabilities:
Accounts receivable, net	(151,191)	(41,444)
Inventories	(94,907)	(45,280)
Prepaid expenses and other assets	(264,909)	(23,709)
Accounts payable	16,153	(12,210)
Accrued expenses	451,084	255,699
Other liabilities	296,477	22,859
Net cash provided by operating activities	2,761,973	1,123,322
Cash flows from investing activities:
Purchases of available-for-sale debt securities	(246,937)	(381,739)
Maturities of available-for-sale debt securities	184,419	375,145
Sale of equity securities	149,595	0
Payment to acquire business, net of cash acquired	0	(245,824)
Expenditures for property and equipment	(212,109)	(58,690)
Investment in equity securities	(19,327)	(27,219)
Net cash used in investing activities	(144,359)	(338,327)
Cash flows from financing activities:
Issuances of common stock under benefit plans	234,854	144,630
Repurchases of common stock	(408,033)	(150,017)
Payments in connection with common stock withheld for employee tax obligations	(179,775)	(5,936)
Payments on finance leases	(31,378)	(28,879)
Proceeds related to finance leases	8,642	1,002
Advance from collaborator	5,000	10,000
Repayments of advanced funding	(2,741)	(4,316)
Other financing activities	(6,658)	(1,132)
Net cash used in financing activities	(380,089)	(34,648)
Effect of changes in exchange rates on cash	2,779	(4,009)
Net increase in cash and cash equivalents	2,240,304	746,338
Cash, cash equivalents and restricted cash—beginning of period	3,120,681	2,658,253
Cash, cash equivalents and restricted cash—end of period	5,360,985	3,404,591
Supplemental disclosure of cash flow information:
Cash paid for interest	40,769	41,704
Cash paid for income taxes	81,684	22,838
Issuances of common stock from employee benefit plans receivable	45	13
Accrued share repurchase liability	$ 0	$ 12,001

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	9 Months Ended
	Sep. 30, 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 (“U.S. 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 Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (the “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 September 30, 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 U.S. 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 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 the Company’s 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 Annual Report on Form 10-K.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) TRIKAFTA/KAFTRIO $ 960,308 $ — $ 2,773,256 $ — SYMDEKO/SYMKEVI 156,178 403,714 501,066 1,085,821 ORKAMBI 225,919 296,711 692,038 906,159 KALYDECO 193,866 249,403 609,503 755,481 Total product revenues, net * $ 1,536,271 $ 949,828 $ 4,575,863 $ 2,747,461 * 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 outside of the United States 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) United States $ 1,224,565 $ 710,323 $ 3,622,467 $ 2,052,044 Outside of the United States Europe 251,366 184,845 766,438 532,809 Other 62,340 54,660 188,958 164,703 Total revenues outside of the United States 313,706 239,505 955,396 697,512 Total revenues $ 1,538,271 $ 949,828 $ 4,577,863 $ 2,749,556 Contract Liabilities The Company had contract liabilities of $94.8 million and $62.3 million as of September 30, 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	9 Months Ended
	Sep. 30, 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 and nine months ended September 30, 2020 and 2019, or were new or otherwise revised during the three and nine months ended September 30, 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 targets. In the fourth quarter of 2019, the Company elected to exclusively license three 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 and nine months ended September 30, 2020, the net expense related to the CTX001 Co-Co Agreement was $14.3 million and $33.4 million, respectively. During the three and nine months ended September 30, 2019, the net expense related to the CTX001 Co-Co Agreement was $7.7 million and $22.3 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”) and the Company made an upfront payment of $175.0 million to CRISPR. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2019. 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. Moderna, Inc. In 2016, the Company entered into a strategic collaboration and licensing agreement with Moderna, Inc. (“Moderna”), pursuant to which the parties are seeking to identify and develop messenger Ribonucleic Acid (“mRNA”) therapeutics for the treatment of cystic fibrosis. In September 2020, the Company entered into a new strategic collaboration and licensing agreement with Moderna (the “2020 Moderna Agreement”) aimed at the discovery and development of lipid nanoparticles and mRNAs that can deliver gene-editing therapies to lung cells for the treatment of cystic fibrosis. Pursuant to the 2020 Moderna Agreement, Moderna received an upfront payment of $75.0 million and is eligible to receive up to $380.0 million in development, regulatory and commercial milestones as well as royalties on net product sales. The Company determined that substantially all of the fair value of the 2020 Moderna Agreement was attributable to in-process research and development and no substantive processes were acquired that would constitute a business. The Company concluded that it did not have any alternative future use for the acquired in-process research and development and recorded the upfront payment to “Research and development expenses” in the third quarter of 2020. 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 an d 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 and nine months ended September 30, 2020 and 2019. Janssen Pharmaceuticals, Inc. In the third quarter of 2020, Janssen Pharmaceuticals, Inc. (“Janssen”) exercised its right to terminate its exclusive worldwide license from the Company to develop and commercialize certain drug candidates for the treatment of influenza, based on Phase 3 clinical trial results for pimodivir. Janssen had been developing pimodivir since 2014. Cystic Fibrosis Foundation

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per ShareBasic 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Net income $ 667,434 $ 57,518 $ 2,107,457 $ 593,576 Basic weighted-average common shares outstanding 260,392 256,946 260,313 256,289 Effect of potentially dilutive securities: Stock options 1,887 2,080 1,936 2,297 Restricted stock and restricted stock units (including PSUs) 1,788 1,434 1,765 1,582 Employee stock purchase program 12 13 17 14 Diluted weighted-average common shares outstanding 264,079 260,473 264,031 260,182 Basic net income per common share $ 2.56 $ 0.22 $ 8.10 $ 2.32 Diluted net income per common share $ 2.53 $ 0.22 $ 7.98 $ 2.28 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Stock options 23 3,303 303 3,116 Unvested restricted stock and restricted stock units (including PSUs) 252 13 229 7

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following fair value hierarchy is used to classify assets and liabilities based on observable inputs and unobservable inputs used in order to determine the fair value of the Company’s financial 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.” 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. During the three and nine months ended September 30, 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 by level within the fair value hierarchy (and does not include $2.2 billion and $2.3 billion of cash as of September 30, 2020 and December 31, 2019, respectively): As of September 30, 2020 As of December 31, 2019 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 3,130,364 $ 3,130,364 $ — $ — $ 791,039 $ 791,039 $ — $ — Corporate debt securities — — — — 6,070 — 6,070 — Commercial paper 5,001 — 5,001 — 29,472 — 29,472 — Marketable securities: Corporate equity securities 312,682 216,142 96,540 — 282,084 261,797 20,287 — Government-sponsored enterprise securities 91,283 91,283 — — 12,733 12,733 — — Corporate debt securities 276,610 — 276,610 — 301,799 — 301,799 — Commercial paper 112,396 — 112,396 — 102,356 — 102,356 — Prepaid expenses and other current assets: Foreign currency forward contracts 673 — 673 — 9,725 — 9,725 — Total financial assets $ 3,929,009 $ 3,437,789 $ 491,220 $ — $ 1,535,278 $ 1,065,569 $ 469,709 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (29,554) $ — $ (29,554) $ — $ (5,533) $ — $ (5,533) $ — Long-term contingent consideration (189,100) — — (189,100) (176,500) — — (176,500) Other long-term liabilities: Foreign currency forward contracts (3,254) — (3,254) — (1,821) — (1,821) — Total financial liabilities $ (221,908) $ — $ (32,808) $ (189,100) $ (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 In 2019, the Company acquired Exonics Therapeutics, Inc. (“Exonics”), a privately-held company focused on creating transformative gene-editing therapies to repair mutations that cause DMD and other severe neuromuscular diseases, including DM1. The Company’s Level 3 contingent consideration liabilities are related to $678.3 million of development and regulatory milestones potentially payable to Exonics’ former equity holders. 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 0.6% and 1.9% as of September 30, 2020, 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 drug candidates in the pharmaceutical industry and the effects of changes in other assumptions including discount rates, the Company expects its estimates regarding the fair value of contingent consideration to 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: Nine Months Ended September 30, 2020 (in thousands) Balance at December 31, 2019 $ 176,500 Increase in fair value of contingent payments 12,600 Balance at September 30, 2020 $ 189,100

Marketable Securities and Equit

Marketable Securities and Equity Investments	9 Months Ended
	Sep. 30, 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 $2.2 billion and $2.3 billion of cash as of September 30, 2020 and December 31, 2019, respectively), is shown below: As of September 30, 2020 As of December 31, 2019 Amortized Cost Gross Gross Fair Value Amortized Cost Gross Gross Fair Value (in thousands) Cash equivalents: Money market funds $ 3,130,364 $ — $ — $ 3,130,364 $ 791,039 $ — $ — $ 791,039 Corporate debt securities — — — — 6,070 — — 6,070 Commercial paper 5,000 1 — 5,001 29,470 3 (1) 29,472 Total cash equivalents $ 3,135,364 $ 1 $ — $ 3,135,365 $ 826,579 $ 3 $ (1) $ 826,581 Marketable securities: Government-sponsored enterprise securities $ 91,256 $ 33 $ (6) $ 91,283 $ 12,689 $ 44 $ — $ 12,733 Corporate debt securities 275,554 1,067 (11) 276,610 301,458 391 (50) 301,799 Commercial paper 112,159 242 (5) 112,396 102,240 121 (5) 102,356 Total marketable debt securities 478,969 1,342 (22) 480,289 416,387 556 (55) 416,888 Corporate equity securities 103,463 209,219 — 312,682 113,829 168,255 — 282,084 Total marketable securities $ 582,432 $ 210,561 $ (22) $ 792,971 $ 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 September 30, 2020 As of December 31, 2019 (in thousands) Cash and cash equivalents $ 3,135,365 $ 826,581 Marketable securities 480,289 416,888 Total $ 3,615,654 $ 1,243,469 Available-for-sale debt securities by contractual maturity were as follows: As of September 30, 2020 As of December 31, 2019 (in thousands) Matures within one year $ 3,514,474 $ 1,137,942 Matures after one year through five years 101,180 105,527 Total $ 3,615,654 $ 1,243,469 The Company has a limited number of available-for-sale debt securities in insignificant loss positions as of September 30, 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 not 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 and nine months ended September 30, 2020 and 2019. As of September 30, 2020 and December 31, 2019, the total fair value of the Company’s strategic investments in the common stock of publicly traded companies was $312.7 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 to “Other income (expense), net” on its condensed consolidated statements of operations. During the three and nine months ended September 30, 2020, the Company recorded net unrealized gains of $69.8 million and $102.3 million, respectively, on corporate equity securities held as of September 30, 2020. During the three and nine months ended September 30, 2019, the Company recorded a net unrealized loss of $31.2 million and a net unrealized gain of $68.9 million, respectively, on corporate equity securities held as of September 30, 2019. During the nine months ended September 30, 2020, the Company received proceeds of $149.6 million related to the sale of the common stock of publicly traded companies, which had a total original weighted-average cost basis of $51.3 million. There were no sales of the common stock of publicly traded companies during the nine months ended September 30, 2019. As of September 30, 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 $20.8 million.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 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 (12,616) 818 (20,913) (32,711) Amounts reclassified from accumulated other comprehensive loss — — (6,298) (6,298) Net current period other comprehensive (loss) income (12,616) 818 (27,211) (39,009) Balance at September 30, 2020 $ (13,511) $ 1,321 $ (28,792) $ (40,982) Balance at December 31, 2018 $ (11,227) $ (536) $ 12,422 $ 659 Other comprehensive income before reclassifications 10,263 1,111 26,663 38,037 Amounts reclassified from accumulated other comprehensive income — — (19,849) (19,849) Net current period other comprehensive income 10,263 1,111 6,814 18,188 Balance at September 30, 2019 $ (964) $ 575 $ 19,236 $ 18,847

Hedging

Hedging	9 Months Ended
	Sep. 30, 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 U.S. GAAP having contractual durations from one 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 September 30, 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 September 30, 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 U.S. GAAP: As of September 30, 2020 As of December 31, 2019 Foreign Currency (in thousands) Euro $ 632,621 $ 501,197 British pound sterling 166,707 87,032 Australian dollar 92,524 89,705 Canadian dollar 74,749 50,452 Total foreign currency forward contracts $ 966,601 $ 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 U.S. GAAP. The Company recognizes realized gains and losses for such contracts in “Other income (expense), net” in its condensed consolidated statements of operations each period. As of September 30, 2020, the notional amount of the Company’s outstanding foreign currency forward contracts where hedge accounting under U.S. GAAP is not applied was $609.9 million. During the three and nine months ended September 30, 2020 and 2019, the Company recognized the following related to foreign currency forward contacts in its condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Designated as hedging instruments - Reclassified from AOCI Product revenues, net $ (7,249) $ 10,304 $ 8,039 $ 25,381 Not designated as hedging instruments Other income (expense), net $ 25,897 $ (8,812) $ 15,724 $ (10,874) Total reported in the Condensed Consolidated Statement of Operations Product revenues, net $ 1,536,271 $ 949,828 $ 4,575,863 $ 2,747,461 Other income (expense), net $ 84,386 $ (31,747) $ 139,621 $ 64,802 The following table summarizes the fair value of the Company’s outstanding foreign currency forward contracts designated as cash flow hedges under U.S. GAAP included on its condensed consolidated balance sheets: As of September 30, 2020 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 673 Other current liabilities $ (29,554) Other assets — Other long-term liabilities (3,254) Total assets $ 673 Total liabilities $ (32,808) 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 September 30, 2020, the Company expects the amounts that are related to foreign exchange forward contracts designated as cash flow hedges under U.S. 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 U.S. GAAP on the Company’s condensed consolidated balance sheets: As of September 30, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 673 $ — $ 673 $ (673) $ — Total liabilities (32,808) — (32,808) 673 (32,135) 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	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following: As of September 30, 2020 As of December 31, 2019 (in thousands) Raw materials $ 42,542 $ 26,247 Work-in-process 135,220 107,021 Finished goods 67,698 34,234 Total $ 245,460 $ 167,502

Stock-based Compensation Expens

Stock-based Compensation Expense and Share Repurchase Programs	9 Months Ended
	Sep. 30, 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 and nine months ended September 30, 2020 and 2019, the Company recognized the following stock-based compensation expense: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Stock-based compensation expense by type of award: Restricted stock and restricted stock units (including PSUs) $ 84,043 $ 61,175 $ 279,611 $ 185,651 Stock options 13,221 21,737 47,334 76,053 ESPP share issuances 3,225 3,044 8,565 8,430 Stock-based compensation expense related to inventories (950) (536) (3,076) (1,236) Total stock-based compensation expense included in costs and expenses $ 99,539 $ 85,420 $ 332,434 $ 268,898 Stock-based compensation expense by line item: Cost of sales $ 1,250 $ 1,337 $ 3,998 $ 4,178 Research and development expenses 60,770 52,504 203,732 167,851 Sales, general and administrative expenses 37,519 31,579 124,704 96,869 Total stock-based compensation expense included in costs and expenses 99,539 85,420 332,434 268,898 Income tax effect (35,295) (21,996) (130,692) (87,638) Total stock-based compensation expense, net of tax $ 64,244 $ 63,424 $ 201,742 $ 181,260 The following table sets forth the Company’s unrecognized stock-based compensation expense as of September 30, 2020, by type of award and the weighted-average period over which that expense is expected to be recognized: As of September 30, 2020 Unrecognized Expense Weighted-average (in thousands) (in years) Type of award: Restricted stock units (including PSUs) $ 487,254 2.06 Stock options $ 76,261 1.95 ESPP share issuances $ 3,265 0.44 The following table summarizes information about stock options outstanding and exercisable as of September 30, 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) $36.28–$40.00 62 1.09 $ 38.06 62 $ 38.06 $40.01–$60.00 157 1.98 $ 47.13 157 $ 47.13 $60.01–$80.00 105 3.49 $ 74.82 104 $ 74.82 $80.01–$100.00 1,029 5.66 $ 88.91 919 $ 89.20 $100.01–$120.00 129 4.39 $ 109.27 128 $ 109.21 $120.01–$140.00 282 4.98 $ 129.42 281 $ 129.43 $140.01–$160.00 740 7.36 $ 155.49 369 $ 155.41 $160.01–$180.00 599 7.76 $ 168.34 282 $ 165.74 $180.01–$200.00 1,252 8.14 $ 185.31 422 $ 184.85 $200.01–$286.27 23 9.67 $ 286.27 23 $ 286.27 Total 4,378 6.63 $ 140.26 2,747 $ 123.22 Share repurchase programs In 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 nine months ended September 30, 2019, the Company repurchased 832,186 shares of its common stock under the 2018 Share Repurchase Program for an aggregate of $150.0 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. In 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. During the nine months ended September 30, 2020, the Company repurchased 1,806,587 shares of its common stock under the 2019 Share Repurchase Program for an aggregate of $408.0 million including commissions and fees. As of September 30, 2020, there was a total of $56.0 million remaining for repurchases under the 2019 Share Repurchase Program. The Company expects to fund further repurchases of its common stock through a combination of cash on hand and cash generated by operations.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 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 and nine months ended September 30, 2020, the Company recorded provisions for income taxes of $78.4 million and $120.7 million, respectively. For the three and nine months ended September 30, 2019, the Company recorded provisions for income taxes of $13.1 million and $124.4 million, respectively. The Company’s effective tax rate for the third quarter of 2020 was lower than the U.S. statutory rate primarily due to a discrete tax benefit associated with an increase in the United Kingdom’s corporate tax rate. The Company’s effective tax rate for the nine months ended September 30, 2020 was also lower than the U.S. statutory rate due to discrete tax benefits associated with an intra-entity transfer of intellectual property rights to the United Kingdom and the write-off of a long-term intercompany receivable as well as excess tax benefits related to stock-based compensation. The Company’s effective tax rate for the three and nine months ended September 30, 2019 was lower than the U.S. statutory rate primarily due to excess tax benefits related to stock-based compensation. In the second quarter of 2020, the Company completed an intra-entity transfer of intellectual property rights to the United Kingdom, resulting in a deferred tax benefit of $209.0 million. The Company expects to be able to utilize the deferred tax asset resulting from the intra-entity transfer. 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. The Company expects to utilize its remaining previously benefited U.S. net operating losses in 2020. As a result, a larger portion of the Company’s tax provision will represent a cash tax payable in future periods. 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 September 30, 2020 and December 31, 2019, the Company had $73.8 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 change 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. The Company did not recognize any material interest or penalties related to uncertain tax positions during the three and nine months ended September 30, 2020 and 2019. As of September 30, 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. The Company files U.S. federal income tax returns and income tax returns in various state, local and foreign jurisdictions. The Company is no longer subject to any tax assessment from an income tax examination in the U.S. or any other major taxing jurisdiction for years before 2011, except where the Company has net operating losses or tax credit carryforwards that originate before 2011. The Company has various income tax audits ongoing at any time throughout the world.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Revolving Credit Facilities The Company and certain of its subsidiaries have entered into two Credit Agreements (the “Credit Agreements”) with Bank of America, N.A., as administrative agent and the lenders referred to therein (the “Lenders”). The Credit Agreements were not drawn upon at closing and the Company has not drawn upon them to date. Amounts drawn pursuant to the Credit Agreements, if any, will be used for general corporate purposes. Any amounts borrowed under the Credit Agreements will bear interest, at the Company’s option, at either a base rate or a Eurocurrency rate, in each case plus an applicable margin 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). In September 2019, the Company and certain of its subsidiaries entered into a $500.0 million unsecured revolving facility (the “2019 Credit Agreement”) with the Lenders, which matures on September 17, 2024. The 2019 Credit Agreement superseded the Company’s credit agreement entered into in 2016 with Bank of America, N.A serving in the same capacity. Under the 2019 Credit Agreement, the applicable margins on base rate loans range from 0.125% to 0.500% and the applicable margins on Eurocurrency loans range from 1.125% to 1.500%. The 2019 Credit Agreement provides a sublimit of $50.0 million for letters of credit. In September 2020, the Company and certain of its subsidiaries entered into a $2.0 billion unsecured revolving facility (the “2020 Credit Agreement”) with the Lenders, which matures on September 18, 2022. Under the 2020 Credit Agreement, the applicable margins on base rate loans range from 0.500% to 0.875% and the applicable margins on Eurocurrency loans range from 1.500% to 1.875%. The 2020 Credit Agreement does not include a sublimit for letters of credit. Subject to satisfaction of certain conditions, the Company may request that the borrowing capacity for each of the Credit Agreements be increased by an additional $500.0 million. Any amounts borrowed pursuant to the Credit Agreements are guaranteed by certain of the Company’s existing and future domestic subsidiaries, subject to certain exceptions. The Credit Agreements contain customary representations and warranties and affirmative and negative covenants, including financial covenants to maintain (x) 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 (y) a consolidated interest coverage ratio of 2.50 to 1.00, in each case measured on a quarterly basis. As of September 30, 2020, the Company was in compliance with the covenants described above. The Credit Agreements also contain 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. Direct costs related to the Credit Agreements, which were not material to the Company’s financial statements, were deferred and recorded over the term of the Credit Agreements. 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 September 30, 2020 or December 31, 2019.

Additional Cash Flow Informatio

Additional Cash Flow Information	9 Months Ended
	Sep. 30, 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: Nine Months Ended September 30, 2020 2019 Beginning of period End of period Beginning of period End of period (in thousands) Cash and cash equivalents $ 3,109,322 $ 5,358,087 $ 2,650,134 $ 3,397,941 Prepaid expenses and other current assets 8,004 2,898 4,910 6,650 Other assets 3,355 — 3,209 — Cash, cash equivalents and restricted cash per statement of cash flows $ 3,120,681 $ 5,360,985 $ 2,658,253 $ 3,404,591

Facilities

Facilities	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Facilities	Facilities Cell and Genetic Therapies Lease In 2019, the Company entered into an agreement to lease approximately 269,000 square feet of office and laboratory space near its corporate headquarters in Boston, MA. The lease agreement includes an initial term of 15 years plus a period to install leasehold improvements, with an option to extend the lease term for up to two additional ten-year periods. The Company expects base rent payments to commence in the fourth quarter of 2021. The Company has utilized the initial period, which commenced in the third quarter of 2020 upon occupation of the building, as its lease term. As of September 30, 2020, the Company recorded a right-of-use asset of $256.8 million and an operating lease liability of $268.5 million related to the lease agreement on its condensed consolidated balance sheet. Boston Continuous Manufacturing Facility In the third quarter of 2020, the Company purchased its continuous manufacturing facility located near its corporate headquarters in Boston, MA from its former landlord for $155.3 million in cash. As of September 30, 2020, the Company adjusted its condensed consolidated balance sheet to (i) classify the building within “Property and equipment, net” with a 40 years useful life, (ii) derecognize a previously recorded right-of-use asset and operating lease liability for the facility and (iii) record a finance lease for the land on which the facility is constructed. The previously recognized right-of-use asset and operating lease liability and the newly recognized finance lease related to the land were not significant to the Company’s condensed consolidated balance sheet for the periods presented.
Facilities	Facilities Cell and Genetic Therapies Lease In 2019, the Company entered into an agreement to lease approximately 269,000 square feet of office and laboratory space near its corporate headquarters in Boston, MA. The lease agreement includes an initial term of 15 years plus a period to install leasehold improvements, with an option to extend the lease term for up to two additional ten-year periods. The Company expects base rent payments to commence in the fourth quarter of 2021. The Company has utilized the initial period, which commenced in the third quarter of 2020 upon occupation of the building, as its lease term. As of September 30, 2020, the Company recorded a right-of-use asset of $256.8 million and an operating lease liability of $268.5 million related to the lease agreement on its condensed consolidated balance sheet. Boston Continuous Manufacturing Facility In the third quarter of 2020, the Company purchased its continuous manufacturing facility located near its corporate headquarters in Boston, MA from its former landlord for $155.3 million in cash. As of September 30, 2020, the Company adjusted its condensed consolidated balance sheet to (i) classify the building within “Property and equipment, net” with a 40 years useful life, (ii) derecognize a previously recorded right-of-use asset and operating lease liability for the facility and (iii) record a finance lease for the land on which the facility is constructed. The previously recognized right-of-use asset and operating lease liability and the newly recognized finance lease related to the land were not significant to the Company’s condensed consolidated balance sheet for the periods presented.

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 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 (“U.S. 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 Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (the “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 September 30, 2020 and 2019.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in accordance with U.S. 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 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 the Company’s 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.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Product revenues, net consisted of the following: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) TRIKAFTA/KAFTRIO $ 960,308 $ — $ 2,773,256 $ — SYMDEKO/SYMKEVI 156,178 403,714 501,066 1,085,821 ORKAMBI 225,919 296,711 692,038 906,159 KALYDECO 193,866 249,403 609,503 755,481 Total product revenues, net * $ 1,536,271 $ 949,828 $ 4,575,863 $ 2,747,461 * The preceding table does not include collaborative and royalty revenues. Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) United States $ 1,224,565 $ 710,323 $ 3,622,467 $ 2,052,044 Outside of the United States Europe 251,366 184,845 766,438 532,809 Other 62,340 54,660 188,958 164,703 Total revenues outside of the United States 313,706 239,505 955,396 697,512 Total revenues $ 1,538,271 $ 949,828 $ 4,577,863 $ 2,749,556

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Net income $ 667,434 $ 57,518 $ 2,107,457 $ 593,576 Basic weighted-average common shares outstanding 260,392 256,946 260,313 256,289 Effect of potentially dilutive securities: Stock options 1,887 2,080 1,936 2,297 Restricted stock and restricted stock units (including PSUs) 1,788 1,434 1,765 1,582 Employee stock purchase program 12 13 17 14 Diluted weighted-average common shares outstanding 264,079 260,473 264,031 260,182 Basic net income per common share $ 2.56 $ 0.22 $ 8.10 $ 2.32 Diluted net income per common share $ 2.53 $ 0.22 $ 7.98 $ 2.28
Schedule of 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Stock options 23 3,303 303 3,116 Unvested restricted stock and restricted stock units (including PSUs) 252 13 229 7

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of 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 by level within the fair value hierarchy (and does not include $2.2 billion and $2.3 billion of cash as of September 30, 2020 and December 31, 2019, respectively): As of September 30, 2020 As of December 31, 2019 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 (in thousands) Financial instruments carried at fair value (asset positions): Cash equivalents: Money market funds $ 3,130,364 $ 3,130,364 $ — $ — $ 791,039 $ 791,039 $ — $ — Corporate debt securities — — — — 6,070 — 6,070 — Commercial paper 5,001 — 5,001 — 29,472 — 29,472 — Marketable securities: Corporate equity securities 312,682 216,142 96,540 — 282,084 261,797 20,287 — Government-sponsored enterprise securities 91,283 91,283 — — 12,733 12,733 — — Corporate debt securities 276,610 — 276,610 — 301,799 — 301,799 — Commercial paper 112,396 — 112,396 — 102,356 — 102,356 — Prepaid expenses and other current assets: Foreign currency forward contracts 673 — 673 — 9,725 — 9,725 — Total financial assets $ 3,929,009 $ 3,437,789 $ 491,220 $ — $ 1,535,278 $ 1,065,569 $ 469,709 $ — Financial instruments carried at fair value (liability positions): Other current liabilities: Foreign currency forward contracts $ (29,554) $ — $ (29,554) $ — $ (5,533) $ — $ (5,533) $ — Long-term contingent consideration (189,100) — — (189,100) (176,500) — — (176,500) Other long-term liabilities: Foreign currency forward contracts (3,254) — (3,254) — (1,821) — (1,821) — Total financial liabilities $ (221,908) $ — $ (32,808) $ (189,100) $ (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: Nine Months Ended September 30, 2020 (in thousands) Balance at December 31, 2019 $ 176,500 Increase in fair value of contingent payments 12,600 Balance at September 30, 2020 $ 189,100

Marketable Securities and Equ_2

Marketable Securities and Equity Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Schedule 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 $2.2 billion and $2.3 billion of cash as of September 30, 2020 and December 31, 2019, respectively), is shown below: As of September 30, 2020 As of December 31, 2019 Amortized Cost Gross Gross Fair Value Amortized Cost Gross Gross Fair Value (in thousands) Cash equivalents: Money market funds $ 3,130,364 $ — $ — $ 3,130,364 $ 791,039 $ — $ — $ 791,039 Corporate debt securities — — — — 6,070 — — 6,070 Commercial paper 5,000 1 — 5,001 29,470 3 (1) 29,472 Total cash equivalents $ 3,135,364 $ 1 $ — $ 3,135,365 $ 826,579 $ 3 $ (1) $ 826,581 Marketable securities: Government-sponsored enterprise securities $ 91,256 $ 33 $ (6) $ 91,283 $ 12,689 $ 44 $ — $ 12,733 Corporate debt securities 275,554 1,067 (11) 276,610 301,458 391 (50) 301,799 Commercial paper 112,159 242 (5) 112,396 102,240 121 (5) 102,356 Total marketable debt securities 478,969 1,342 (22) 480,289 416,387 556 (55) 416,888 Corporate equity securities 103,463 209,219 — 312,682 113,829 168,255 — 282,084 Total marketable securities $ 582,432 $ 210,561 $ (22) $ 792,971 $ 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 September 30, 2020 As of December 31, 2019 (in thousands) Cash and cash equivalents $ 3,135,365 $ 826,581 Marketable securities 480,289 416,888 Total $ 3,615,654 $ 1,243,469 Available-for-sale debt securities by contractual maturity were as follows: As of September 30, 2020 As of December 31, 2019 (in thousands) Matures within one year $ 3,514,474 $ 1,137,942 Matures after one year through five years 101,180 105,527 Total $ 3,615,654 $ 1,243,469

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of 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 (12,616) 818 (20,913) (32,711) Amounts reclassified from accumulated other comprehensive loss — — (6,298) (6,298) Net current period other comprehensive (loss) income (12,616) 818 (27,211) (39,009) Balance at September 30, 2020 $ (13,511) $ 1,321 $ (28,792) $ (40,982) Balance at December 31, 2018 $ (11,227) $ (536) $ 12,422 $ 659 Other comprehensive income before reclassifications 10,263 1,111 26,663 38,037 Amounts reclassified from accumulated other comprehensive income — — (19,849) (19,849) Net current period other comprehensive income 10,263 1,111 6,814 18,188 Balance at September 30, 2019 $ (964) $ 575 $ 19,236 $ 18,847

Hedging (Tables)

Hedging (Tables)	9 Months Ended
	Sep. 30, 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 U.S. GAAP: As of September 30, 2020 As of December 31, 2019 Foreign Currency (in thousands) Euro $ 632,621 $ 501,197 British pound sterling 166,707 87,032 Australian dollar 92,524 89,705 Canadian dollar 74,749 50,452 Total foreign currency forward contracts $ 966,601 $ 728,386
Schedule of Foreign Exchange Contracts, Condensed Consolidated Statements of Operations	During the three and nine months ended September 30, 2020 and 2019, the Company recognized the following related to foreign currency forward contacts in its condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Designated as hedging instruments - Reclassified from AOCI Product revenues, net $ (7,249) $ 10,304 $ 8,039 $ 25,381 Not designated as hedging instruments Other income (expense), net $ 25,897 $ (8,812) $ 15,724 $ (10,874) Total reported in the Condensed Consolidated Statement of Operations Product revenues, net $ 1,536,271 $ 949,828 $ 4,575,863 $ 2,747,461 Other income (expense), net $ 84,386 $ (31,747) $ 139,621 $ 64,802
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 U.S. GAAP included on its condensed consolidated balance sheets: As of September 30, 2020 Assets Liabilities Classification Fair Value Classification Fair Value (in thousands) Prepaid expenses and other current assets $ 673 Other current liabilities $ (29,554) Other assets — Other long-term liabilities (3,254) Total assets $ 673 Total liabilities $ (32,808) 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)
Schedule of Offsetting Liabilities	The following table summarizes the potential effect of offsetting derivatives by type of financial instrument designated as cash flow hedges under U.S. GAAP on the Company’s condensed consolidated balance sheets: As of September 30, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 673 $ — $ 673 $ (673) $ — Total liabilities (32,808) — (32,808) 673 (32,135) 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 —
Schedule of Offsetting Assets	The following table summarizes the potential effect of offsetting derivatives by type of financial instrument designated as cash flow hedges under U.S. GAAP on the Company’s condensed consolidated balance sheets: As of September 30, 2020 Gross Amounts Recognized Gross Amounts Offset Gross Amounts Presented Gross Amounts Not Offset Legal Offset Foreign currency forward contracts (in thousands) Total assets $ 673 $ — $ 673 $ (673) $ — Total liabilities (32,808) — (32,808) 673 (32,135) 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)	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories by Type	Inventories consisted of the following: As of September 30, 2020 As of December 31, 2019 (in thousands) Raw materials $ 42,542 $ 26,247 Work-in-process 135,220 107,021 Finished goods 67,698 34,234 Total $ 245,460 $ 167,502

Stock-based Compensation Expe_2

Stock-based Compensation Expense and Share Repurchase Programs (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Stock-based Compensation Expense by Line Item	During the three and nine months ended September 30, 2020 and 2019, the Company recognized the following stock-based compensation expense: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Stock-based compensation expense by type of award: Restricted stock and restricted stock units (including PSUs) $ 84,043 $ 61,175 $ 279,611 $ 185,651 Stock options 13,221 21,737 47,334 76,053 ESPP share issuances 3,225 3,044 8,565 8,430 Stock-based compensation expense related to inventories (950) (536) (3,076) (1,236) Total stock-based compensation expense included in costs and expenses $ 99,539 $ 85,420 $ 332,434 $ 268,898 Stock-based compensation expense by line item: Cost of sales $ 1,250 $ 1,337 $ 3,998 $ 4,178 Research and development expenses 60,770 52,504 203,732 167,851 Sales, general and administrative expenses 37,519 31,579 124,704 96,869 Total stock-based compensation expense included in costs and expenses 99,539 85,420 332,434 268,898 Income tax effect (35,295) (21,996) (130,692) (87,638) Total stock-based compensation expense, net of tax $ 64,244 $ 63,424 $ 201,742 $ 181,260
Schedule of Unrecognized Stock-based Compensation Expense, Net of Estimated Forfeitures	The following table sets forth the Company’s unrecognized stock-based compensation expense as of September 30, 2020, by type of award and the weighted-average period over which that expense is expected to be recognized: As of September 30, 2020 Unrecognized Expense Weighted-average (in thousands) (in years) Type of award: Restricted stock units (including PSUs) $ 487,254 2.06 Stock options $ 76,261 1.95 ESPP share issuances $ 3,265 0.44
Schedule of Stock Options Outstanding and Exercisable	The following table summarizes information about stock options outstanding and exercisable as of September 30, 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) $36.28–$40.00 62 1.09 $ 38.06 62 $ 38.06 $40.01–$60.00 157 1.98 $ 47.13 157 $ 47.13 $60.01–$80.00 105 3.49 $ 74.82 104 $ 74.82 $80.01–$100.00 1,029 5.66 $ 88.91 919 $ 89.20 $100.01–$120.00 129 4.39 $ 109.27 128 $ 109.21 $120.01–$140.00 282 4.98 $ 129.42 281 $ 129.43 $140.01–$160.00 740 7.36 $ 155.49 369 $ 155.41 $160.01–$180.00 599 7.76 $ 168.34 282 $ 165.74 $180.01–$200.00 1,252 8.14 $ 185.31 422 $ 184.85 $200.01–$286.27 23 9.67 $ 286.27 23 $ 286.27 Total 4,378 6.63 $ 140.26 2,747 $ 123.22

Additional Cash Flow Informat_2

Additional Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of 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: Nine Months Ended September 30, 2020 2019 Beginning of period End of period Beginning of period End of period (in thousands) Cash and cash equivalents $ 3,109,322 $ 5,358,087 $ 2,650,134 $ 3,397,941 Prepaid expenses and other current assets 8,004 2,898 4,910 6,650 Other assets 3,355 — 3,209 — Cash, cash equivalents and restricted cash per statement of cash flows $ 3,120,681 $ 5,360,985 $ 2,658,253 $ 3,404,591

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)segment	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment	1
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Increase in accumulated deficit	$ (254,479)	$ 1,852,978
Cumulative effect adjustment for adoption of new accounting guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in accumulated deficit			$ 40,300

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 1,538,271	$ 949,828	$ 4,577,863	$ 2,749,556
United States
Disaggregation of Revenue [Line Items]
Revenues	1,224,565	710,323	3,622,467	2,052,044
Europe
Disaggregation of Revenue [Line Items]
Revenues	251,366	184,845	766,438	532,809
Other
Disaggregation of Revenue [Line Items]
Revenues	62,340	54,660	188,958	164,703
Total revenues outside of the United States
Disaggregation of Revenue [Line Items]
Revenues	313,706	239,505	955,396	697,512
Product revenues, net
Disaggregation of Revenue [Line Items]
Revenues	1,536,271	949,828	4,575,863	2,747,461
TRIKAFTA/KAFTRIO
Disaggregation of Revenue [Line Items]
Revenues	960,308	0	2,773,256	0
SYMDEKO/SYMKEVI
Disaggregation of Revenue [Line Items]
Revenues	156,178	403,714	501,066	1,085,821
ORKAMBI
Disaggregation of Revenue [Line Items]
Revenues	225,919	296,711	692,038	906,159
KALYDECO
Disaggregation of Revenue [Line Items]
Revenues	$ 193,866	$ 249,403	$ 609,503	$ 755,481

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract liabilities	$ 94.8	$ 62.3

Collaborative Arrangements (Det

Collaborative Arrangements (Details)	1 Months Ended		3 Months Ended				9 Months Ended
	Sep. 30, 2020USD ($)	Jul. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)target	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
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			$ 14,300,000			$ 7,700,000	$ 33,400,000	$ 22,300,000
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
Collaborative arrangement, up-front payment paid		$ 175,000,000
Moderna, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, development and regulatory potential milestone payments maximum	$ 380,000,000
Collaborative arrangement, up-front payment paid	$ 75,000,000

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Computation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net income	$ 667,434	$ 57,518	$ 2,107,457	$ 593,576
Basic weighted-average common shares outstanding (in shares)	260,392	256,946	260,313	256,289
Effect of potentially dilutive securities:
Employee stock purchase program (in shares)	12	13	17	14
Diluted weighted-average common shares outstanding (in shares)	264,079	260,473	264,031	260,182
Basic net income per common share (in dollars per share)	$ 2.56	$ 0.22	$ 8.10	$ 2.32
Diluted net income per common share (in dollars per share)	$ 2.53	$ 0.22	$ 7.98	$ 2.28
Stock options
Effect of potentially dilutive securities:
Share-based payment arrangements (in shares)	1,887	2,080	1,936	2,297
Restricted stock and restricted stock units (including PSUs)
Effect of potentially dilutive securities:
Share-based payment arrangements (in shares)	1,788	1,434	1,765	1,582

Earnings Per Share - Anti-dilut

Earnings Per Share - Anti-dilutive Securities (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	23	3,303	303	3,116
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)	252	13	229	7

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash	$ 2,200	$ 2,300
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Remaining milestone payment	$ 678.3
Level 3 | Minimum | Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, measurement input (as a percent)	0.006
Level 3 | Maximum | Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, measurement input (as a percent)	0.019

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Subject to Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financial instruments carried at fair value (liability positions):
Long-term contingent consideration	$ (189,100)	$ (176,500)
Recurring Basis
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	673	9,725
Total financial assets	3,929,009	1,535,278
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	(29,554)	(5,533)
Long-term contingent consideration	(189,100)	(176,500)
Derivative liability noncurrent, foreign currency forward contracts	(3,254)	(1,821)
Total financial liabilities	(221,908)	(183,854)
Recurring Basis | Level 1
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	0	0
Total financial assets	3,437,789	1,065,569
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	0	0
Long-term contingent consideration	0	0
Derivative liability noncurrent, foreign currency forward contracts	0	0
Total financial liabilities	0	0
Recurring Basis | Level 2
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	673	9,725
Total financial assets	491,220	469,709
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	(29,554)	(5,533)
Long-term contingent consideration	0	0
Derivative liability noncurrent, foreign currency forward contracts	(3,254)	(1,821)
Total financial liabilities	(32,808)	(7,354)
Recurring Basis | Level 3
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	0	0
Total financial assets	0	0
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	0	0
Long-term contingent consideration	(189,100)	(176,500)
Derivative liability noncurrent, foreign currency forward contracts	0	0
Total financial liabilities	(189,100)	(176,500)
Recurring Basis | Money market funds
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	3,130,364	791,039
Recurring Basis | Money market funds | Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	3,130,364	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 | Corporate equity securities
Financial instruments carried at fair value (asset positions):
Marketable securities	312,682	282,084
Recurring Basis | Corporate equity securities | Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	216,142	261,797
Recurring Basis | Corporate equity securities | Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	96,540	20,287
Recurring Basis | Corporate equity securities | Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis | Government-sponsored enterprise securities
Financial instruments carried at fair value (asset positions):
Marketable securities	91,283	12,733
Recurring Basis | Government-sponsored enterprise securities | Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	91,283	12,733
Recurring Basis | Government-sponsored enterprise securities | Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis | Government-sponsored enterprise 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):
Cash and cash equivalents	0	6,070
Marketable securities	276,610	301,799
Recurring Basis | Corporate debt securities | Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Marketable securities	0	0
Recurring Basis | Corporate debt securities | Level 2
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	6,070
Marketable securities	276,610	301,799
Recurring Basis | Corporate debt securities | Level 3
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Marketable securities	0	0
Recurring Basis | Commercial paper
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	5,001	29,472
Marketable securities	112,396	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	5,001	29,472
Marketable securities	112,396	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

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Contingent Consideration Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 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	$ 1,800	$ 2,959	12,600	$ 2,959
Balance at September 30, 2020	$ 189,100		$ 189,100

Marketable Securities and Equ_3

Marketable Securities and Equity Investments - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Summary of cash, cash equivalents and marketable securities
Cash	$ 2,200,000,000		$ 2,200,000,000		$ 2,300,000,000
Other-than-temporary declines in fair value of available-for-sale debt securities	0	$ 0	0	$ 0
Fair value	312,682,000		312,682,000		282,084,000
Unrealized gain (loss)	69,800,000	$ (31,200,000)	102,300,000	68,900,000
Equity securities, cost basis	103,463,000		103,463,000		113,829,000
Other Assets
Summary of cash, cash equivalents and marketable securities
Equity securities without readily determinable fair value, amount	20,800,000		20,800,000
Corporate Equity Securities
Summary of cash, cash equivalents and marketable securities
Fair value	312,700,000		312,700,000		$ 282,100,000
Publically Traded Companies
Summary of cash, cash equivalents and marketable securities
Proceeds from sale and maturity of marketable securities			149,600,000	$ 0
Equity securities, cost basis	$ 51,300,000		$ 51,300,000

Marketable Securities and Equ_4

Marketable Securities and Equity Investments - Summary of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Total marketable debt securities
Fair Value	$ 3,615,654	$ 1,243,469
Corporate equity securities
Amortized Cost	103,463	113,829
Gross Unrealized Gains	209,219	168,255
Gross Unrealized Losses	0	0
Fair Value	312,682	282,084
Amortized Cost	582,432	530,216
Gross Unrealized Gains	210,561	168,811
Gross Unrealized Losses	(22)	(55)
Fair Value	792,971	698,972
Cash equivalents
Total marketable debt securities
Amortized Cost	3,135,364	826,579
Gross Unrealized Gains	1	3
Gross Unrealized Losses	0	(1)
Fair Value	3,135,365	826,581
Cash equivalents | Money market funds
Total marketable debt securities
Amortized Cost	3,130,364	791,039
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	3,130,364	791,039
Cash equivalents | Corporate debt securities
Total marketable debt securities
Amortized Cost	0	6,070
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	6,070
Cash equivalents | Commercial paper
Total marketable debt securities
Amortized Cost	5,000	29,470
Gross Unrealized Gains	1	3
Gross Unrealized Losses	0	(1)
Fair Value	5,001	29,472
Marketable securities
Total marketable debt securities
Amortized Cost	478,969	416,387
Gross Unrealized Gains	1,342	556
Gross Unrealized Losses	(22)	(55)
Fair Value	480,289	416,888
Marketable securities | Government-sponsored enterprise securities
Total marketable debt securities
Amortized Cost	91,256	12,689
Gross Unrealized Gains	33	44
Gross Unrealized Losses	(6)	0
Fair Value	91,283	12,733
Marketable securities | Corporate debt securities
Total marketable debt securities
Amortized Cost	275,554	301,458
Gross Unrealized Gains	1,067	391
Gross Unrealized Losses	(11)	(50)
Fair Value	276,610	301,799
Marketable securities | Commercial paper
Total marketable debt securities
Amortized Cost	112,159	102,240
Gross Unrealized Gains	242	121
Gross Unrealized Losses	(5)	(5)
Fair Value	$ 112,396	$ 102,356

Marketable Securities and Equ_5

Marketable Securities and Equity Investments - Available-for-Sale Debt Securities at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt securities	$ 3,615,654	$ 1,243,469
Cash and cash equivalents
Debt Securities, Available-for-sale [Line Items]
Debt securities	3,135,365	826,581
Marketable securities
Debt Securities, Available-for-sale [Line Items]
Debt securities	$ 480,289	$ 416,888

Marketable Securities and Equ_6

Marketable Securities and Equity Investments - Available-for-Sale Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Matures within one year	$ 3,514,474	$ 1,137,942
Matures after one year through five years	101,180	105,527
Total	$ 3,615,654	$ 1,243,469

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 7,519,242	$ 5,069,965	$ 6,085,244	$ 4,435,203
Other comprehensive (loss) income before reclassifications			(32,711)	38,037
Amounts reclassified from accumulated other comprehensive income (loss)			(6,298)	(19,849)
Total other comprehensive (loss) income	(26,861)	22,048	(39,009)	18,188
Ending balance	8,133,473	5,253,394	8,133,473	5,253,394
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(895)	(11,227)
Other comprehensive (loss) income before reclassifications			(12,616)	10,263
Amounts reclassified from accumulated other comprehensive income (loss)			0	0
Total other comprehensive (loss) income			(12,616)	10,263
Ending balance	(13,511)	(964)	(13,511)	(964)
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			818	1,111
Amounts reclassified from accumulated other comprehensive income (loss)			0	0
Total other comprehensive (loss) income			818	1,111
Ending balance	1,321	575	1,321	575
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			(20,913)	26,663
Amounts reclassified from accumulated other comprehensive income (loss)			(6,298)	(19,849)
Total other comprehensive (loss) income			(27,211)	6,814
Ending balance	(28,792)	19,236	(28,792)	19,236
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(14,121)	(3,201)	(1,973)	659
Total other comprehensive (loss) income	(26,861)	22,048	(39,009)	18,188
Ending balance	$ (40,982)	$ 18,847	$ (40,982)	$ 18,847

Hedging - Additional Informatio

Hedging - Additional Information (Details) - Foreign Currency Forward Contracts	9 Months Ended
	Sep. 30, 2020USD ($)
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative term	1 month
Cash Flow Hedging | Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 609,900,000
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	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 966,601	$ 728,386
Euro
Derivative [Line Items]
Notional amount of foreign currency forward contract	632,621	501,197
British pound sterling
Derivative [Line Items]
Notional amount of foreign currency forward contract	166,707	87,032
Australian dollar
Derivative [Line Items]
Notional amount of foreign currency forward contract	92,524	89,705
Canadian dollar
Derivative [Line Items]
Notional amount of foreign currency forward contract	$ 74,749	$ 50,452

Hedging - Cash Flow Hedging Ins

Hedging - Cash Flow Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	$ 1,538,271	$ 949,828	$ 4,577,863	$ 2,749,556
Other income (expense), net	84,386	(31,747)	139,621	64,802
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 income (expense), net	25,897	(8,812)	15,724	(10,874)
Product revenues, net
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	1,536,271	949,828	4,575,863	2,747,461
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	$ (7,249)	$ 10,304	$ 8,039	$ 25,381

Hedging - Derivative Fair Value

Hedging - Derivative Fair Value (Details) - Designated as Hedging Instruments - Foreign Currency Forward Contracts - Cash Flow Hedging - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Total assets	$ 673	$ 9,725
Total liabilities	(32,808)	(7,354)
Prepaid expenses and other current assets
Derivative [Line Items]
Total assets	673	9,725
Other assets
Derivative [Line Items]
Total assets	0	0
Other current liabilities
Derivative [Line Items]
Total liabilities	(29,554)	(5,533)
Other long-term liabilities
Derivative [Line Items]
Total liabilities	$ (3,254)	$ (1,821)

Hedging - Offsetting Derivative

Hedging - Offsetting Derivatives (Details) - Cash Flow Hedging - Designated as Hedging Instruments - Foreign Currency Forward Contracts - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Offsetting Derivative Assets [Abstract]
Gross Amounts Recognized	$ 673	$ 9,725
Gross Amounts Offset	0	0
Gross Amounts Presented	673	9,725
Gross Amounts Not Offset	(673)	(7,354)
Legal Offset	0	2,371
Offsetting Derivative Liabilities [Abstract]
Gross Amounts Recognized	(32,808)	(7,354)
Gross Amounts Offset	0	0
Gross Amounts Presented	(32,808)	(7,354)
Gross Amounts Not Offset	673	7,354
Legal Offset	$ (32,135)	$ 0

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 42,542	$ 26,247
Work-in-process	135,220	107,021
Finished goods	67,698	34,234
Total	$ 245,460	$ 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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	$ 99,539	$ 85,420	$ 332,434	$ 268,898
Stock-based compensation expense related to inventories	(950)	(536)	(3,076)	(1,236)
Total stock-based compensation expense included in costs and expenses	99,539	85,420	332,434	268,898
Income tax effect	(35,295)	(21,996)	(130,692)	(87,638)
Total stock-based compensation expense, net of tax	64,244	63,424	201,742	181,260
Cost of sales
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	1,250	1,337	3,998	4,178
Research and development expenses
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	60,770	52,504	203,732	167,851
Sales, general and administrative expenses
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	37,519	31,579	124,704	96,869
Restricted stock and restricted stock units (including PSUs)
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	84,043	61,175	279,611	185,651
Stock options
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	13,221	21,737	47,334	76,053
ESPP share issuances
Stock-based compensation expense:
Total stock-based compensation expense included in costs and expenses	$ 3,225	$ 3,044	$ 8,565	$ 8,430

Stock-based Compensation Expe_4

Stock-based Compensation Expense and Share Repurchase Programs - Unrecognized Stock-based Compensation Expense (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Restricted stock units (including PSUs)
Type of award:
Unrecognized Expense	$ 487,254
Weighted-average Recognition Period	2 years 21 days
Stock options
Type of award:
Unrecognized Expense	$ 76,261
Weighted-average Recognition Period	1 year 11 months 12 days
ESPP share issuances
Type of award:
Unrecognized Expense	$ 3,265
Weighted-average Recognition Period	5 months 8 days

Stock-based Compensation Expe_5

Stock-based Compensation Expense and Share Repurchase Programs - Stock Options Outstanding and Exercisable (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price range, options outstanding (in shares) | shares	4,378
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	6 years 7 months 17 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 140.26
Exercise price range, options exercisable (in shares) | shares	2,747
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 123.22
$36.28–$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)	36.28
Exercise price, high end of range (in dollars per share)	$ 40
Exercise price range, options outstanding (in shares) | shares	62
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	1 year 1 month 2 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 38.06
Exercise price range, options exercisable (in shares) | shares	62
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 38.06
$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	157
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	1 year 11 months 23 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 47.13
Exercise price range, options exercisable (in shares) | shares	157
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 47.13
$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	105
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	3 years 5 months 26 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 74.82
Exercise price range, options exercisable (in shares) | shares	104
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 74.82
$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	1,029
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	5 years 7 months 28 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 88.91
Exercise price range, options exercisable (in shares) | shares	919
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 89.20
$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	129
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	4 years 4 months 20 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 109.27
Exercise price range, options exercisable (in shares) | shares	128
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 109.21
$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	282
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	4 years 11 months 23 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 129.42
Exercise price range, options exercisable (in shares) | shares	281
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 129.43
$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	740
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	7 years 4 months 9 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 155.49
Exercise price range, options exercisable (in shares) | shares	369
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	599
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	7 years 9 months 3 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 168.34
Exercise price range, options exercisable (in shares) | shares	282
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 165.74
$180.01–$200.00
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)	$ 200
Exercise price range, options outstanding (in shares) | shares	1,252
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	8 years 1 month 20 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 185.31
Exercise price range, options exercisable (in shares) | shares	422
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 184.85
$200.01–$286.27
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise price, low end of range (in dollars per share)	200.01
Exercise price, high end of range (in dollars per share)	$ 286.27
Exercise price range, options outstanding (in shares) | shares	23
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	9 years 8 months 1 day
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 286.27
Exercise price range, options exercisable (in shares) | shares	23
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 286.27

Stock-based Compensation Expe_6

Stock-based Compensation Expense and Share Repurchase Programs - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Amount of shares repurchased	$ 108,007,000	$ 12,001,000	$ 408,033,000	$ 162,018,000
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)				832,186
Amount of shares repurchased				$ 150,000,000
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)			1,806,587
Amount of shares repurchased			$ 408,000,000
Stock repurchase program, remaining amount	$ 56,000,000		$ 56,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 78,437	$ 13,148	$ 120,718	$ 124,393
Discrete income tax benefit			209,000
Deferred tax assets, valuation allowance					$ 205,200
Unrecognized tax benefits	$ 73,800		$ 73,800		$ 33,900

Commitments and Contingencies (

Commitments and Contingencies (Details)	1 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)credit_agreement	Dec. 31, 2019USD ($)
Line of Credit Facility [Line Items]
Number of credit agreements | credit_agreement			2
Indemnification claims	$ 0		$ 0
Contingent liabilities	0		0	$ 0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	2,000,000,000	$ 500,000,000	2,000,000,000
Line of credit facility additional borrowing capacity	$ 500,000,000	$ 500,000,000	$ 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 (as a percent)	0.50%	0.125%
Revolving Credit Facility | Base Rate | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.875%	0.50%
Revolving Credit Facility | Eurodollar | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.50%	1.125%
Revolving Credit Facility | Eurodollar | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.875%	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	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 5,358,087	$ 3,109,322	$ 3,397,941	$ 2,650,134
Cash, cash equivalents and restricted cash per statement of cash flows	5,360,985	3,120,681	3,404,591	2,658,253
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	2,898	8,004	6,650	4,910
Other assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and cash equivalents	$ 0	$ 3,355	$ 0	$ 3,209

Facilities (Details)

Facilities (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019ft²renewal_option
Lessee, Lease, Description [Line Items]
Right of use assets	$ 256.8	$ 256.8
Operating lease liability	268.5	$ 268.5
Cell and Genetic Therapies Lease
Lessee, Lease, Description [Line Items]
Area of real estate property (in square feet) | ft²			269,000
Lease agreement initial term			15 years
Number of optional renewal terms | renewal_option			2
Optional renewal term length			10 years
Boston Continuous Manufacturing
Lessee, Lease, Description [Line Items]
Payments to purchase buildings in cash	$ 155.3
Property equipment, useful life		40 years