Ironwood Pharmaceuticals (IRWD) 10-Q 6 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - $ / shares	3 Months Ended
	Mar. 31, 2020	May 01, 2020
Cover [Abstract]
Entity Central Index Key	0001446847
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-34620
Entity Registrant Name	IRONWOOD PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3404176
Entity Address, Address Line One	100 Summer Street
Entity Address, Address Line Two	Suite 2300
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	621-7722
Title of 12(b) Security	Class A common stock, $0.001 par value
Entity Listing, Par Value Per Share	$ 0.001
Trading Symbol	IRWD
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		159,378,637
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 231,143	$ 177,023
Accounts receivable, net	17,703	11,279
Related party accounts receivable, net	73,404	105,967
Inventory, net		648
Prepaid expenses and other current assets	10,443	10,685
Restricted cash	1,250	1,250
Total current assets	333,943	306,852
Restricted cash, net of current portion	971	971
Accounts receivable, net of current portion	22,795	32,597
Property and equipment, net	12,164	12,429
Operating lease right-of-use assets	17,447	17,743
Convertible note hedges	15,847	31,366
Other assets	838	790
Total assets	404,005	402,748
Current liabilities:
Accounts payable	2,781	3,978
Related party accounts payable, net	1,058	1,509
Accrued research and development costs	2,286	2,956
Accrued expenses and other current liabilities	18,719	30,465
Current portion of operating lease liabilities	1,876	1,146
Deferred revenue	875	875
Total current liabilities	27,595	40,929
Note hedge warrants	12,207	24,260
Convertible senior notes	413,409	407,994
Operating lease obligations, net of current portion	21,646	22,082
Other liabilities	705	734
Commitments and contingencies
Stockholders' deficit:
Preferred stock, $0.001 par value, 75,000,000 shares authorized, no shares issued and outstanding
Class A Common Stock, $0.001 par value, 500,000,000 shares authorized and 159,368,126 issued and outstanding at March 31, 2020 and 500,000,000 shares authorized and 157,535,962 shares issued and outstanding at December 31, 2019	159	158
Additional paid-in capital	1,497,171	1,478,823
Accumulated deficit	(1,568,887)	(1,572,232)
Total stockholders' deficit	(71,557)	(93,251)
Total liabilities and stockholders' deficit	$ 404,005	$ 402,748

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	75,000,000	75,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	159,368,126	157,535,962
Common stock, shares outstanding	159,368,126	157,535,962

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Total revenues	$ 79,943	$ 68,730
Cost and expenses:
Cost of revenues	2,239	1,043
Research and development	28,027	32,198
Selling, general and administrative	36,450	49,095
Restructuring expenses	0	3,328
Total cost and expenses	66,716	85,664
Income (loss) from operations	13,227	(16,934)
Other (expense) income:
Interest expense	(7,220)	(9,592)
Interest and investment income	777	736
(Loss) gain on derivatives	(3,466)	3,944
Other income	27
Other expense, net	(9,882)	(4,912)
Net income (loss) from continuing operations	3,345	(21,846)
Net loss from discontinued operations		(37,438)
Net income (loss) and comprehensive income	$ 3,345	$ (59,284)
Net income per share from continuing operations - basic and diluted (in dollars per share)	$ 0.02	$ (0.14)
Net loss per share from discontinued operations - basic and diluted (in dollars per share)		(0.24)
Net income (loss) per share - basic and diluted (in dollars per share)	$ 0.02	$ (0.38)
Weighted average shares used in computing net income (loss) per share - basic	158,374	154,956
Weighted average shares used in computing net income (loss) per share - diluted	159,970	154,956
Collaborative arrangements revenue
Revenues:
Total revenues	$ 74,445	$ 66,152
Sale of active pharmaceutical ingredient
Revenues:
Total revenues	$ 5,498	$ 2,578

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Deficit - USD ($) $ in Thousands	Class A common stockCommon Stock	Additional paid-in capital	Accumulated deficit	Total
Balance at Dec. 31, 2018	$ 154	$ 1,394,603	$ (1,591,128)	$ (196,371)
Balance (in shares) at Dec. 31, 2018	154,414,691
Increase (Decrease) in Stockholders' Equity
Issuance of common stock related to share-based awards and employee stock purchase plan	$ 2	3,486		3,488
Issuance of common stock related to share-based awards and employee stock purchase plan (in shares)	1,210,858
Share-based compensation expense related to share-based awards and employee stock purchase plan		14,988		14,988
Net loss			(59,284)	(59,284)
Balance at Mar. 31, 2019	$ 156	1,413,077	(1,650,412)	(237,179)
Balance (in shares) at Mar. 31, 2019	155,625,549
Balance at Dec. 31, 2019	$ 158	1,478,823	(1,572,232)	$ (93,251)
Balance (in shares) at Dec. 31, 2019	157,535,962			157,535,962
Increase (Decrease) in Stockholders' Equity
Issuance of common stock related to share-based awards and employee stock purchase plan	$ 1	11,984		$ 11,985
Issuance of common stock related to share-based awards and employee stock purchase plan (in shares)	1,832,164
Share-based compensation expense related to share-based awards and employee stock purchase plan		6,364		6,364
Net loss			3,345	3,345
Balance at Mar. 31, 2020	$ 159	$ 1,497,171	$ (1,568,887)	$ (71,557)
Balance (in shares) at Mar. 31, 2020	159,368,126			159,368,126

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net Income (Loss)	$ 3,345	$ (59,284)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	682	688
Loss on disposal of property and equipment	16	99
Share-based compensation expense	6,364	13,934
Change in fair value of note hedge warrants	(12,053)	5,625
Change in fair value of convertible note hedges	15,519	(9,569)
Non-cash interest expense	5,416	4,609
Changes in assets and liabilities:
Accounts receivable and related party accounts receivable, net	35,941	8,333
Prepaid expenses and other current assets	301	2,482
Inventory, net		(152)
Other assets	(51)	52
Accounts payable, related party accounts payable and accrued expenses	(11,768)	(21,824)
Accrued research and development costs	(670)	621
Operating lease right-of-use assets	296	3,466
Operating lease liabilities	294	(2,829)
Other liabilities	(29)
Net cash provided by (used in) continuing operating activities	43,603	(53,749)
Net cash provided by discontinued operating activities		11,364
Net cash provided by (used in) operating activities	43,603	(42,385)
Cash flows from investing activities:
Purchases of property and equipment	(1,438)	988
Proceeds from sale of property and equipment		258
Net cash (used in) provided by continuing investing activities	(1,438)	1,246
Net cash used in discontinued investing activities		(4,223)
Net cash used in investing activities	(1,438)	(2,977)
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan	11,955	3,487
Payments on 2026 Notes		(12,252)
Net cash provided by (used in) continuing financing activities	11,955	(8,765)
Net cash provided by (used in) financing activities	11,955	(8,765)
Net increase (decrease) in cash, cash equivalents and restricted cash	54,120	(54,127)
Cash, cash equivalents and restricted cash, beginning of period	179,244	180,848
Cash, cash equivalents and restricted cash, end of period	$ 233,364	$ 126,721

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	$ 231,143	$ 119,045
Restricted cash	2,221	7,676
Total cash, cash equivalents, and restricted cash	$ 233,364	$ 126,721

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Nature of Business	1. Nature of Business ​ Ironwood Pharmaceuticals, Inc. (“Ironwood” or the “Company”) is a gastrointestinal (“GI”) healthcare company dedicated to advancing the treatment of GI diseases and redefining the standard of care for millions of GI patients. The Company is focused on the development and commercialization of innovative GI product opportunities in areas of large unmet need, leveraging its demonstrated expertise and capabilities in GI diseases. ​ LINZESS ® ® to adult men and women suffering from IBS-C or CIC in Canada, and to adult men and women suffering from IBS-C in certain European countries. ​ The Company has strategic partnerships with leading pharmaceutical companies to support the development and commercialization of linaclotide throughout the world. The Company and its partner, Allergan plc (together with its affiliates) (“Allergan”), began commercializing LINZESS in the U.S. in December 2012. Under the Company’s collaboration with Allergan for North America, total net sales of LINZESS in the U.S., as recorded by Allergan, are reduced by commercial costs incurred by each party, and the resulting amount is shared equally between the Company and Allergan. Allergan also has an exclusive license from the Company to develop and commercialize linaclotide in all countries other than China (including Hong Kong and Macau), Japan and the countries and territories of North America (the “Allergan License Territory”). On a country-by-country and product-by-product basis in the Allergan License Territory, Allergan pays the Company a royalty as a percentage of net sales of products containing linaclotide as an active ingredient. In addition, Allergan has exclusive rights to commercialize linaclotide in Canada as CONSTELLA and in Mexico as LINZESS. ​ Astellas Pharma Inc. (“Astellas”), the Company’s partner in Japan, has an exclusive license to develop and commercialize linaclotide in Japan. In March 2017, Astellas began commercializing LINZESS for the treatment of adults with IBS-C in Japan, and in September 2018, Astellas began commercializing LINZESS for the treatment of adults with chronic constipation in Japan. In August 2019, the Company amended and restated its license agreement with Astellas. Beginning in 2020, the Company will no longer be responsible for the supply of linaclotide active pharmaceutical ingredient (“API”) to Astellas (Note 4). ​ In October 2012, the Company and AstraZeneca AB (together with its affiliates) (“AstraZeneca”) entered into a collaboration agreement to co-develop and co-commercialize linaclotide in China (including Hong Kong and Macau) (the “AstraZeneca License Territory”). In September 2019, the Company amended its existing collaboration agreement with AstraZeneca. As of September 16, 2019, AstraZeneca has the exclusive right to develop, manufacture, and commercialize products containing linaclotide in the AstraZeneca License Territory (Note 4). In November 2019, AstraZeneca began commercializing LINZESS for the treatment of adults with IBS-C in China. ​ The Company and Allergan are exploring ways to enhance the clinical profile of LINZESS by studying linaclotide in additional indications, populations and formulations to assess its potential to treat various conditions. In June 2019, the Company announced positive topline data from its Phase IIIb trial demonstrating the efficacy and safety of LINZESS 290 mcg on the overall abdominal symptoms of bloating, pain and discomfort, in adult patients with IBS-C. ​ The Company and Allergan are advancing MD-7246, a delayed release formulation of linaclotide, as an oral, intestinal, non-opioid, pain-relieving agent for patients with abdominal pain associated with certain GI diseases. In May 2019, the Company and Allergan announced the initiation of a Phase II clinical trial evaluating the safety and efficacy of MD-7246 in adult patients with abdominal pain associated with IBS with diarrhea (“IBS-D”). In March 2020, the Company announced that patient dosing in the IBS-D Phase II clinical trial was complete. ​ The Company also is developing IW-3718, a gastric retentive formulation of a bile acid sequestrant, for the potential treatment of refractory gastroesophageal reflux disease (“refractory GERD”). In June 2018, the Company initiated two Phase III clinical trials evaluating the safety and efficacy of IW-3718 in patients with refractory GERD. ​ Additionally, the Company periodically enters into co-promotion agreements to bolster its salesforce productivity. In August 2019, the Company entered into a disease education and promotional agreement with Alnylam Pharmaceuticals, Inc. (“Alnylam”) for Alnylam’s GIVLAARI TM ​ These and other agreements are more fully described in Note 4, Collaboration, License, Co-Promotion and Other Commercial Agreements ​ On April 1, 2019, Ironwood completed the separation (the “Separation”) of its soluble guanylate cyclase (“sGC”) business, and certain other assets and liabilities, into Cyclerion Therapeutics, Inc. (“Cyclerion”). The Separation was effected by means of a distribution of all of the outstanding shares of common stock, with no par value, of Cyclerion through a dividend of all outstanding shares of Cyclerion’s common stock, to Ironwood’s stockholders of record as of the close of business on March 19, 2019 (Note 2). ​ In August 2019, the Company issued $200.0 million in aggregate principal amount of 0.75% Convertible Senior Notes due 2024 (the “2024 Convertible Notes”) and $200.0 million in aggregate principal amount of 1.50% Convertible Senior Notes due 2026 (the “2026 Convertible Notes”). The Company received net proceeds of approximately $391.0 million from the sale of the 2024 Convertible Notes and the 2026 Convertible Notes, after deducting fees and expenses of approximately $9.0 million. The proceeds from the issuance of the 2024 Convertible Notes and the 2026 Convertible Notes were used in August 2019 to pay the cost of associated capped call transactions (the “Capped Calls”) and to repurchase $215.0 million aggregate principal amount of the existing 2.25% Convertible Senior Notes due 2022 (the “2022 Convertible Notes”) and in September 2019 to redeem all of the outstanding principal balance of the 8.375% Notes due 2026 (the “2026 Notes”) (Note 8). ​ Basis of Presentation ​ The accompanying condensed consolidated financial statements and the related disclosures are unaudited and have been prepared in accordance with accounting principles generally accepted in the U.S. Additionally, certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the Securities and Exchange Commission on February 13, 2020 (the “2019 Annual Report on Form 10-K”). ​ The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all normal recurring adjustments considered necessary for a fair presentation of the Company’s financial position as of March 31, 2020, and the results of its operations for the three months ended March 31, 2020 and 2019, its statements of stockholders’ deficit for the three months ended March 31, 2020 and 2019, and its cash flows for the three months ended March 31, 2020 and 2019. The results of operations for the three months ended March 31, 2020 and 2019 are not necessarily indicative of the results that may be expected for the full year or any other subsequent interim period. ​ The Company has presented its sGC business as discontinued operations in its condensed consolidated financial statements for all periods presented. The historical financial statements and footnotes have been recast accordingly (Note 2). For periods following the Separation, the Company continues to report financial results under one business segment. ​ Principles of Consolidation ​ The accompanying condensed consolidated financial statements include the accounts of Ironwood and its wholly-owned subsidiaries as of March 31, 2020, Ironwood Pharmaceuticals Securities Corporation and Ironwood Pharmaceuticals GmbH. Cyclerion was a wholly-owned subsidiary until it became an independent, publicly-traded company on April 1, 2019. All intercompany transactions and balances are eliminated in consolidation. ​ Use of Estimates ​ The preparation of condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles requires the Company’s management to make estimates and judgments that may 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. On an ongoing basis, the Company’s management evaluates its estimates, judgments and methodologies. Significant estimates and assumptions in the condensed consolidated financial statements include those related to revenue recognition; accounts receivable; inventory valuation and related reserves; useful lives of long-lived assets; impairment of long-lived assets, including goodwill; valuation procedures for right-of-use assets and operating lease liabilities; valuation procedures for the issuance and repurchase of convertible notes; losses related to discontinued operations; fair value of derivatives; balance sheet classification of convertible notes; income taxes, including the valuation allowance for deferred tax assets; research and development expenses; contingencies and share-based compensation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ materially from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known. ​ Reclassifications of Prior Period Financial Statements ​ Certain prior period financial statement items have been reclassified to conform to current period presentation. The Company has presented its sGC business as discontinued operations in its condensed consolidated financial statements for prior periods presented. The historical financial statements and footnotes have been recast accordingly. ​ Summary of Significant Accounting Policies ​ The Company’s significant accounting policies are described in Note 2, Summary of Significant Accounting Policies ​ New Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Except as set forth below, the Company did not adopt any new accounting pronouncements during the three months ended March 31, 2020 that had a material effect on its condensed consolidated financial statements. ​ In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Date Codification Improvements to Topic 326, Financial Instruments—Credit Losses Financial Instruments—Credit Losses (Topic 326) and Leases (Topic 842): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842) Financial Instruments—Credit Losses ​ In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirement for Fair Value Measurement In August 2018, the FASB issued ASU No. 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 (a consensus of the FASB Emerging Issues Task Force) In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , No other accounting standards known by the Company to be applicable to it that have been issued by the FASB or other standard-setting bodies and that do not require adoption until a future date are expected to have a material impact on the Company’s condensed consolidated financial statements upon adoption.

Cyclerion Separation

Cyclerion Separation	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Cyclerion Separation	2. Cyclerion Separation ​ On April 1, 2019, Ironwood completed the Separation of Cyclerion. The Separation was effected by means of a distribution of all of the outstanding shares of common stock, with no par value, of Cyclerion through a dividend of Cyclerion’s common stock, to Ironwood’s stockholders of record as of the close of business on March 19, 2019. Prior to the Separation on April 1, 2019, Cyclerion was a wholly owned subsidiary of the Company. On March 30, 2019, the Company entered into certain agreements with Cyclerion relating to the Separation, including a separation agreement, a tax matters agreement, and an employee matters agreement. ​ Agreements with Cyclerion ​ The separation agreement with Cyclerion, dated as of March 30, 2019, sets forth, among other things, the Company’s agreements with Cyclerion regarding the principal actions to be taken in connection with the Separation, including the dividend, which was effective as of April 1, 2019. The separation agreement identifies assets transferred, liabilities assumed by and contracts assigned to each of Cyclerion and Ironwood as part of the Separation, and provides for when and how these transfers, assumptions and assignments occur. The purpose of the separation agreement was to provide Cyclerion and Ironwood with assets to operate their respective businesses and retain or assume liabilities related to those assets. ​ The transfer of assets and liabilities to Cyclerion was effected through a contribution in accordance with the separation agreement as summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 1, 2019 ​ Assets: ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 1,169 ​ Property and equipment, net ​ ​ 10,241 ​ Other assets ​ ​ 21 ​ ​ ​ $ 11,431 ​ Liabilities: ​ ​ ​ ​ Accrued research and development costs ​ $ 5,673 ​ Accrued expenses and other current liabilities ​ ​ 3,149 ​ ​ ​ $ 8,822 ​ Net Assets Transferred to Cyclerion ​ $ 2,609 ​ ​ In addition, the Company received approximately $1.3 million during the year ended December 31, 2019 associated with tenant improvement reimbursement provisions related to the Cyclerion lease in accordance with the separation agreement. ​ The tax matters agreement, dated as of March 30, 2019, governs each party’s rights, responsibilities and obligations with respect to taxes, including taxes, if any, incurred as a result of any failure of the Separation to qualify as tax-free. In general, if the parties incur tax liabilities in the event that the Separation is not tax-free, each party is expected to be responsible for any taxes imposed on Ironwood or Cyclerion that arise from the failure of the Separation to qualify as a transaction that is generally tax-free for U.S. federal income tax purposes, under Sections 355 and 368(a)(1)(D) and certain other relevant provisions of the Internal Revenue Code of 1986, as amended, to the extent that the failure to so qualify is attributable to an acquisition of stock or assets of, or certain actions, omissions or failures to act of, such party. If both Ironwood and Cyclerion are responsible for such failure, liability will be shared according to relative fault. U.S. tax otherwise resulting from the failure of the Separation to qualify as a transaction that is tax-free generally will be the responsibility of Ironwood. Each party otherwise agreed to indemnify the other party from and against any liability for taxes allocated to such party under the tax matters agreement and any taxes resulting from breach of any such party’s covenants under the tax matters agreement, the separation agreement, or any ancillary agreement entered into in connection with the Separation. Cyclerion agreed to certain covenants that contain restrictions intended to preserve the tax-free status of the distribution and certain related transactions. ​ The employee matters agreement, dated as of March 30, 2019, allocates assets, liabilities and responsibilities relating to the employment, compensation, and employee benefits of Ironwood and Cyclerion employees, and other related matters in connection with the Separation, including the treatment of outstanding Ironwood incentive equity awards. Pursuant to the employee matters agreement, the outstanding Ironwood equity awards held by Cyclerion and Ironwood employees were adjusted in connection with the Separation, with the intent to maintain, immediately following the Separation, the economic value of the awards. ​ Additionally, the Company entered into two transition services agreements and a development agreement with Cyclerion. ​ Pursuant to the transition service agreements, the Company was obligated to provide and was entitled to receive certain transition services related to corporate functions, such as finance, procurement, facilities and development. Services provided by the Company to Cyclerion were to continue for an initial term of one the Separation (as applicable), unless earlier terminated or extended according to the terms of the transition services agreement. Services provided by Cyclerion to the Company continued for a term of one year from the date of the Separation. Services received and performed under each transition services agreement were paid at a mutually agreed upon rate. Amounts received for services provided to Cyclerion were recorded as other income and amounts paid for services provided by Cyclerion were recorded as selling, general and administrative expense and research and development expense, as applicable. The transition services agreements terminated on March 31, 2020. During the three months ended March 31, 2020, the Company recorded an insignificant amount as other income for services provided to Cyclerion. During the three months ended March 31, 2020, the Company recorded an insignificant amount in selling, general and administrative expense for services provided by Cyclerion. ​ Pursuant to the development agreement, Cyclerion is obligated to provide the Company with certain research and development services with respect to certain of Ironwood’s products and product candidates, including MD-7246 and IW-3718. Such research and development activities are governed by a joint steering committee comprised of representatives from both Cyclerion and Ironwood. Services received are paid at a mutually agreed upon rate. The Company recorded approximately $1.0 million in research and development expenses under the development agreement during the three months ended March 31, 2020. ​ Discontinued Operations ​ Upon Separation, the Company determined its sGC business qualified for discontinued operations accounting treatment in accordance with Accounting Standards Codification (“ASC”) 205-20. The following is a summary of expenses of Cyclerion for the three months ended March 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2020 2019 Costs and expenses: ​ ​ ​ ​ ​ ​ ​ Research and development ​ $ — $ 21,792 ​ Selling, general and administrative ​ ​ — ​ 15,646 ​ Net loss from discontinued operations ​ $ — ​ $ 37,438 ​ ​ There were no assets and liabilities

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Net Income (Loss) Per Share	3. Net Income (Loss) Per Share ​ Basic and diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding during the period. ​ In June 2015, in connection with the issuance of the 2022 Convertible Notes (Note 8), the Company entered into convertible note hedge transactions, or the Convertible Note Hedges. The Convertible Note Hedges are generally expected to reduce the potential dilution to the Company’s Class A common stockholders upon a conversion of the 2022 Convertible Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted 2022 Convertible Notes in the event that the market price per share of the Company’s Class A Common Stock, as measured under the terms of the Convertible Note Hedges, is greater than the conversion price of the 2022 Convertible Notes. The Convertible Note Hedges are not considered for purposes of calculating the number of diluted weighted average shares outstanding, as their effect would be antidilutive. ​ Concurrently with entering into the Convertible Note Hedges, the Company also sold note hedge warrant, or the Note Hedge Warrants, to the Convertible Note Hedge counterparties to acquire shares of the Company’s Class A Common Stock, subject to customary anti-dilution adjustments (Note 8). The Note Hedge Warrants could have a dilutive effect on the Company’s Class A Common Stock to the extent that the market price per share of the Class A Common Stock exceeds the applicable strike price of such warrants. The Note Hedge Warrants are not considered for purposes of calculating the number of diluted weighted averages shares outstanding, as their effect would be anti-dilutive. ​ In August 2019, in connection with the issuance of the 2024 Convertible Notes and the 2026 Convertible Notes, the Company entered into the Capped Calls. The Capped Calls are generally expected to reduce the potential dilution to the Company’s Class A common stockholders upon a conversion of the 2024 Convertible Notes or the 2026 Convertible Notes and/or offset any cash payments that the Company is required to make in excess of the principal amount of converted 2024 Convertible Notes or 2026 Convertible Notes in the event that the market price per share of the Company’s Class A Common Stock, as measured under the terms of the Capped Calls, is greater than the conversion price of the 2024 Convertible Notes or the 2026 Convertible Notes. The Capped Calls are not considered for purposes of calculating the number of diluted weighted average shares outstanding, as their effect would be anti-dilutive. ​ As applicable, the following potentially dilutive securities have been excluded from the computation of diluted weighted average shares outstanding, when their effect would be anti-dilutive (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Options to purchase Class A Common Stock ​ 15,647 24,080 Shares subject to repurchase 182 32 Time-vesting restricted stock units ​ 4,945 ​ 3,641 ​ Performance-based restricted stock units ​ 543 ​ — ​ Shares subject to issuance under Employee Stock Purchase Plan ​ 105 ​ 125 ​ Note Hedge Warrants ​ 8,318 ​ 20,250 ​ 2022 Convertible Notes ​ 8,318 ​ 20,250 ​ 2024 Convertible Notes ​ 14,934 ​ — ​ 2026 Convertible Notes ​ 14,934 ​ — ​ ​ 67,926 68,378 ​ ​

Collaboration, License, Co-Prom

Collaboration, License, Co-Promotion and Other Commercial Agreements	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Collaboration, License, Co-Promotion and Other Commercial Agreements	4. Collaboration, License, Co-Promotion and Other Commercial Agreements ​ For the three months ended March 31, 2020, the Company had linaclotide collaboration agreements with Allergan for North America and AstraZeneca for China (including Hong Kong and Macau), as well as linaclotide license agreements with Astellas for Japan and with Allergan for the Allergan License Territory. The Company also had an agreement with Alnylam to perform disease awareness activities for AHP and sales detailing activities for GIVLAARI. The following table provides amounts included in the Company’s condensed consolidated statements of operations as collaborative arrangements revenue and sale of API primarily attributable to transactions from these arrangements (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ Collaborative Arrangements Revenue ​ 2020 2019 ​ Linaclotide Collaboration Agreements: ​ ​ ​ ​ ​ ​ ​ Allergan (North America) ​ $ 71,692 ​ $ 64,785 ​ Allergan (Europe and other) ​ ​ 643 ​ ​ 420 ​ AstraZeneca (China, including Hong Kong and Macau) ​ ​ 332 ​ — ​ Astellas (Japan) ​ ​ 479 ​ — ​ Co-Promotion and Other Agreements: ​ ​ ​ ​ ​ ​ ​ Alnylam (GIVLAARI) ​ ​ 945 ​ ​ — ​ Other ​ ​ 354 ​ ​ 947 ​ Total collaborative arrangements revenue ​ $ 74,445 ​ $ 66,152 ​ Sale of API Linaclotide License Agreements: ​ ​ ​ ​ ​ ​ ​ Astellas (Japan) ​ $ — ​ $ 2,575 ​ AstraZeneca (China, including Hong Kong and Macau) ​ ​ 5,498 ​ ​ — ​ Other ​ ​ — ​ ​ 3 ​ Total sale of API ​ $ 5,498 ​ $ 2,578 ​ ​ Accounts receivable, net included approximately $40.5 million and approximately $43.9 million related to collaborative arrangements revenue and sale of API, collectively, as of March 31, 2020 and December 31, 2019, respectively. Related party accounts receivable, net included approximately $73.4 million and approximately $110.1 million related to collaborative arrangements revenue, net of approximately $4.6 million and approximately $4.1 million related to related party accounts payable as of March 31, 2020 and December 31, 2019, respectively. As of March 31, 2020, deferred revenue was approximately $0.9 million related to the disease education and promotional agreement with Alnylam. ​ The Company routinely assesses the creditworthiness of its license and collaboration partners. The Company has not experienced any material losses related to receivables from its license or collaboration partners. ​ Linaclotide Agreements ​ Collaboration Agreement for North America with Allergan ​ In September 2007, the Company entered into a collaboration agreement with Allergan to develop and commercialize linaclotide for the treatment of IBS-C, CIC and other GI conditions in North America. Under the terms of this collaboration agreement, the Company received a non-refundable, upfront licensing fee and shares equally with Allergan all development costs as well as net profits or losses from the development and sale of linaclotide in the U.S. The Company receives royalties in the mid-teens’ percent based on net sales in Canada and Mexico. Allergan is solely responsible for the further development, regulatory approval and commercialization of linaclotide in those countries and funding any costs. The collaboration agreement for North America also includes contingent milestone payments, as well as a contingent equity investment, based on the achievement of specific development and commercial milestones. At March 31, 2020, $205.0 million in license fees and all six development milestone payments had been received by the Company, as well as a $25.0 million equity investment in the Company’s capital stock. The Company can also achieve up to $100.0 million in a sales-related milestone if certain conditions are met, which will be recognized as collaborative arrangements revenue when it is probable that a significant reversal of revenue would not occur and the associated constraints have been lifted. ​ During the three months ended March 31, 2020 and 2019, the Company incurred approximately $6.6 million and approximately $10.0 million in total research and development expenses under the linaclotide collaboration for North America, respectively. As a result of the research and development cost-sharing provisions of the linaclotide collaboration for North America, the Company incurred approximately $0.8 million and offset approximately $3.2 million in research and development costs during the three months ended March 31, 2020 and 2019, respectively, to reflect the obligations of each party under the collaboration to bear half of the development costs incurred. ​ The Company and Allergan began commercializing LINZESS in the U.S. in December 2012. The Company receives 50% of the net profits and bears 50% of the net losses from the commercial sale of LINZESS in the U.S. Net profits or net losses consist of net sales of LINZESS to third-party customers and sublicense income in the U.S. less the cost of goods sold as well as selling, general and administrative expenses. LINZESS net sales are calculated and recorded by Allergan and may include gross sales net of discounts, rebates, allowances, sales taxes, freight and insurance charges, and other applicable deductions. ​ The Company evaluated its collaboration arrangement for North America with Allergan under ASC Topic 606, Revenue from Contracts with Customers Under the Company’s collaboration agreement with Allergan for North America, LINZESS net sales are calculated and recorded by Allergan and include gross sales net of discounts, rebates, allowances, sales taxes, freight and insurance charges, and other applicable deductions, as noted above. These amounts include the use of estimates and judgments, which could be adjusted based on actual results in the future. The Company records its share of the net profits or net losses from the sales of LINZESS in the U.S. on a net basis less commercial expenses and presents the settlement payments to and from Allergan as collaboration expense or collaborative arrangements revenue, as applicable. This treatment is in accordance with the Company’s revenue recognition policy, given that the Company is not the primary obligor and does not have the inventory risks in the collaboration agreement with Allergan for North America. The Company relies on Allergan to provide accurate and complete information related to net sales of LINZESS in accordance with U.S. generally accepted accounting principles in order to calculate its settlement payments to and from Allergan and record collaboration expense or collaborative arrangements revenue, as applicable. ​ The Company recognized collaborative arrangements revenue from the Allergan collaboration agreement for North America during the three months ended March 31, 2020 and 2019 as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Collaborative arrangements revenue related to sales of LINZESS in the U.S. ​ $ 71,142 ​ $ 64,293 ​ Royalty revenue ​ 550 ​ 492 ​ Total collaborative arrangements revenue ​ $ 71,692 ​ $ 64,785 ​ ​ The collaborative arrangements revenue recognized in the three months ended March 31, 2020 and 2019 primarily represents the Company’s share of the net profits and net losses on the sale of LINZESS in the U.S. ​ The following table presents the amounts recorded by the Company for commercial efforts related to LINZESS in the U.S. in the three months ended March 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Collaborative arrangements revenue related to sales of LINZESS in the U.S. (1) ​ $ 71,142 ​ $ 64,293 ​ Selling, general and administrative costs incurred by the Company (1) ​ (8,674) ​ (10,277) ​ The Company’s share of net profit ​ $ 62,468 ​ $ 54,016 ​ (1) Includes only collaborative arrangements revenue or selling, general and administrative costs attributable to the cost-sharing arrangement with Allergan. Excludes approximately $0.2 million and approximately $0.5 million for the three months ended March 31, 2020 and 2019, respectively, related to patent prosecution and patent litigation costs recognized in connection with the collaboration agreement with Allergan for North America. ​ In May 2014, CONSTELLA became commercially available in Canada and, in June 2014, LINZESS became commercially available in Mexico. The Company records royalties on sales of CONSTELLA in Canada and LINZESS in Mexico in the period earned. The Company recognized approximately $0.6 million and approximately $0.5 million of combined royalty revenues from Canada and Mexico during the three months ended March 31, 2020 and 2019, respectively. ​ License Agreement with Allergan (All countries other than the countries and territories of North America, China, (including Hong Kong and Macau), and Japan) ​ In April 2009, the Company entered into a license agreement with Almirall, S.A. (“Almirall”) to develop and commercialize linaclotide in Europe (including the Commonwealth of Independent States and Turkey) for the treatment of IBS-C, CIC and other GI conditions (the “European License Agreement”). In accordance with the European License Agreement, the Company granted Almirall a right to access its U.S. Phase III clinical trial data for the purposes of supporting European regulatory approval. In October 2015, Almirall transferred its exclusive license to develop and commercialize linaclotide in Europe to Allergan. ​ Additionally, in October 2015, the Company and Allergan separately entered into an amendment to the European License Agreement relating to the development and commercialization of linaclotide in Europe. Pursuant to the terms of the amendment, (i) certain sales-based milestones payable to the Company under the European License Agreement were modified to increase the total milestone payments such that, when aggregated with certain commercial launch milestones, they could total up to $42.5 million, (ii) the royalties payable to the Company during the term of the European License Agreement were modified such that the royalties based on sales volume in Europe begin in the mid- single digit percent and escalate to the upper-teens percent by calendar year 2019, and (iii) Allergan assumed responsibility for the manufacturing of linaclotide API for Europe from the Company, as well as the associated costs. The Company concluded that the 2015 amendment to the European License Agreement was not a modification to the linaclotide collaboration agreement with Allergan for North America. ​ In January 2017, the Company and Allergan entered into an amendment to the European License Agreement (the “2017 Amendment”). The 2017 Amendment extended the license to develop and commercialize linaclotide in all countries other than China (including Hong Kong and Macau), Japan, and the countries and territories of North America. On a country-by-country and product-by-product basis in such additional territory, Allergan is obligated to pay the Company a royalty as a percentage of net sales of products containing linaclotide as an active ingredient in the upper-single digits for five years following the first commercial sale of a linaclotide product in a country, and in the low-double digits thereafter. The royalty rate for products in the expanded territory will decrease, on a country-by-country basis, to the lower-single digits, or cease entirely, following the occurrence of certain events. The 2017 Amendment did not modify any of the milestones or royalty terms related to Europe. In evaluating the terms of the European License Agreement and the 2017 Amendment under ASC 606, the Company determined that there are no remaining performance obligations. However, the Company continues to be eligible to receive consideration in the form of commercial launch milestones, sales-based milestones, and royalties. The commercial launch milestones, sales-based milestones and royalties under the European License Agreement and the 2017 Amendment relate predominantly to the license granted to Allergan (formerly Almirall). The Company records royalties on sales of CONSTELLA in Europe in the period earned based on royalty reports from its partner, if available, or the projected sales and historical trends under the sales-based royalty exception. The commercial launch milestones are recognized as revenue when it is probable that a significant reversal of revenue would not occur and the associated constraint has been lifted. The Company recognized approximately $0.6 million and approximately $0.4 million of royalty revenue from the 2017 Amendment during the three months ended March 31, 2020 and 2019, respectively. ​ License Agreement for Japan with Astellas ​ In November 2009, the Company entered into a license agreement with Astellas, as amended, to develop and commercialize linaclotide for the treatment of IBS-C, CIC and other GI conditions in Japan (the “2009 License Agreement with Astellas”). Astellas is responsible for all activities relating to development, regulatory approval and commercialization in Japan as well as funding the associated costs and the Company was required to participate on a joint development committee over linaclotide’s development period. During the year ended December 31, 2017, the Company and Astellas entered into a commercial API supply agreement (the “Astellas Commercial Supply Agreement”). Pursuant to the Astellas Commercial Supply Agreement, the Company sells linaclotide API supply to Astellas at a contractually defined rate and recognizes related revenue as sale of API. Under the 2009 License Agreement with Astellas, the Company received royalties which escalated based on sales volume, beginning in the low-twenties percent, less the transfer price paid for the API included in the product sold and other contractual deductions. Under the 2009 License Agreement with Astellas, the Company received an up-front licensing fee of $30.0 million and three development milestone payments that totaled $45.0 million, which were recognized as revenue prior to the adoption of ASC 606 on January 1, 2018. ​ The Company evaluated the terms of the 2009 License Agreement with Astellas and determined that there were no remaining performance obligations as of the adoption of ASC 606. Additionally, under the terms of the Astellas Commercial Supply Agreement, the Company determined it had an ongoing performance obligation to supply API. ​ During the three months ended March 31, 2019, the Company recognized approximately $2.6 million from the sale of API to Astellas under the 2009 License Agreement with Astellas and the Astellas Commercial Supply Agreement. The royalties on sales of LINZESS in Japan did not exceed the transfer price of API sold and other contractual deductions during each of the periods presented. In August 2019, the Company and Astellas amended and restated the 2009 License Agreement with Astellas (the “Amended Astellas License Agreement”). This amendment was a modification to the 2009 License Agreement with Astellas and was accounted for as a new and separate contract. Under the terms of the Amended Astellas License Agreement, the Company will no longer be responsible for the supply of linaclotide API to Astellas, and Astellas will be responsible for its own supply of linaclotide API in Japan beginning in 2020. ​ In connection with the execution of the Amended Astellas License Agreement, Astellas paid the Company a non-refundable upfront payment of $10.0 million in August 2019. Further, beginning in 2020, Astellas, in lieu of the royalty payment terms set forth in the 2009 License Agreement with Astellas, is required to pay royalties to the Company at rates beginning in the mid-single digit percent and escalating to low-double-digit percent, based on aggregate annual net sales in Japan of products containing linaclotide API. These royalty payments will be subject to reduction following the expiration of certain licensed patents and the occurrence of generic competition in Japan. The Company continued to supply linaclotide API for Japan during 2019 at a contractually defined rate. Additionally, Astellas will reimburse the Company for the Company’s performance of adverse event reporting services at a fixed monthly rate until such services are terminated. ​ The Company identified the following performance obligations under the Amended Astellas License Agreement: ● delivery of the expanded license of intellectual property, including the applicable manufacturing know-how; ● obligation to supply linaclotide API for 2019; and ● adverse event reporting services. ​ The Company allocated the $10.0 million upfront payment to the delivery of the expanded license of intellectual property and recognized it as collaborative arrangements revenue at contract inception. The Company allocated the approximately $20.4 million in remaining purchase orders for API to the obligation to supply linaclotide API to Astellas for 2019. Consideration for the supply of linaclotide API is recognized over the performance period as linaclotide API is shipped to Astellas using an output method. Consideration allocated to the adverse event reporting services is recognized as such services are provided over the performance period based on the amount to which the Company has a right to invoice using an output method. ​ Royalties on sales of LINZESS in Japan relate predominantly to the license granted to Astellas. Accordingly, the Company applies the sales-based royalty exception and records royalties on sales of LINZESS in Japan in the period earned based on royalty reports from its partner, if available, or the projected sales and historical trends. ​ The Company recognized approximately $0.5 million in collaborative arrangements revenue during the three months ended March 31, 2020 under the Amended Astellas License Agreement, of which approximately $0.4 million related to royalties and an insignificant amount related to adverse event reporting services. ​ Collaboration Agreement for China (including Hong Kong and Macau) with AstraZeneca ​ In October 2012, the Company entered into a collaboration agreement with AstraZeneca to co-develop and co-commercialize linaclotide in the AstraZeneca License Territory (the “AstraZeneca Collaboration Agreement”). The collaboration provided AstraZeneca with an exclusive nontransferable license to exploit the underlying technology in the AstraZeneca License Territory. The parties shared responsibility for continued development and commercialization of linaclotide under a joint development plan and a joint commercialization plan, respectively, with AstraZeneca having primary responsibility for the local operational execution. In September 2019, the Company and AstraZeneca entered into an amendment and restatement of the AstraZeneca Collaboration Agreement (the “Amended AstraZeneca Agreement”) under which AstraZeneca obtained the exclusive right to develop, manufacture and commercialize products containing linaclotide in the AstraZeneca License Territory (the “AstraZeneca License”). ​ Prior to the execution of the Amended AstraZeneca Agreement, the Company identified the following performance obligations under the AstraZeneca Collaboration Agreement: ● research, development and regulatory services pursuant to the development plan (“R&D Services”); ● Joint Development Committee (“JDC”) services; ● obligation to supply clinical trial material; and ● Joint Commercialization Committee services. Under the original AstraZeneca Collaboration Agreement, the Company shared development costs with AstraZeneca, with AstraZeneca incurring 55% of the net losses from the development and commercialization of linaclotide in the AstraZeneca License Territory. Payments from AstraZeneca with respect to both research and development and selling, general and administrative costs incurred by the Company prior to the commercialization of linaclotide in the AstraZeneca License Territory were recorded as a reduction in expense. Development costs incurred by the Company that pertained to the joint development plan and subsequent amendments to the joint development plan, as approved by the JDC, were recorded as research and development expense as incurred. Payments to AstraZeneca were recorded as incremental research and development expense. During the three months ended March 31, 2019, the Company offset an insignificant amount of costs related to R&D Services and JDC services under the AstraZeneca Collaboration Agreement. During the three months ended March 31, 2019, the Company recognized an insignificant amount of revenue related to the sale of linaclotide drug product and API under the AstraZeneca Collaboration Agreement. Additionally, the Company recorded approximately $0.2 million in costs related to pre-launch commercial services and supply chain services during the three months ended March 31, 2019. Under the Amended AstraZeneca Agreement, the Company will receive non-contingent payments totaling $35.0 million in three installments through 2024. In addition, AstraZeneca may be required to make milestone payments totaling up to ​ The Company evaluated the Amended AstraZeneca Agreement in accordance with ASC 606 and determined that it would be treated as a separate contract because it adds a distinct good or service at an amount that reflects standalone selling price. The following performance obligations under the Amended AstraZeneca Agreement were identified: ● delivery of the expanded AstraZeneca License; ● AstraZeneca TSA services; and ● supply of linaclotide API, finished drug product and finished goods under the AstraZeneca CSA. ​ The Company determined that the non-contingent payments should be allocated to the delivery of the AstraZeneca License. The non-contingent payments totaling $35.0 million will be paid in installments through 2024. The Company determined that the performance obligation related to the transfer of the AstraZeneca License was satisfied as of the execution date of the Amended AstraZeneca Agreement. As a portion of the payments relating to the transfer of the AstraZeneca License are due significantly after the performance obligation was satisfied, the Company adjusted its transaction price for the significant financing component of approximately $2.6 million. Accordingly, the Company recognized approximately $32.4 million relating to the delivery of the AstraZeneca License as collaborative arrangements revenue at contract inception and will recognize the approximately $2.6 million relating to the significant financing component as interest income through 2024 using the effective interest method. Consideration allocated to the AstraZeneca TSA services will be recognized as collaborative arrangements revenue as such services are provided over the performance period using an output method based on the amount to which the Company has a right to invoice. Consideration for the supply of linaclotide API, finished drug product and finished goods under the AstraZeneca CSA will be recognized over the performance period using an output method as linaclotide API, finished drug product and finished goods are shipped to AstraZeneca. ​ During the three months ended March 31, 2020, the Company recognized approximately $0.2 million in collaborative arrangements revenue under the Amended AstraZeneca Agreement related to the AstraZeneca TSA services. During the three months ended March 31, 2020, the Company recognized approximately $5.5 million of sale of API on its condensed consolidated statement of operations relating to the supply of linaclotide finished drug product and finished goods under the AstraZeneca CSA. The Company recognized approximately $0.2 million in interest income related to the significant financing component of the Amended AstraZeneca Agreement during the three months ended March 31, 2020. ​ Co-Promotion Agreements ​ Disease Education and Promotional Agreement with Alnylam ​ ​ ​ ● performance of disease education activities for AHP and performance of sales details for GIVLAARI (together “Givosiran Education and Promotion Activities”). ​ ​ ​ Other Collaboration and License Agreements ​ The Company has other collaboration and license agreements that are not individually significant to its business. Pursuant to the terms of one agreement, the Company may be required to pay up to $18.0 million for regulatory milestones, none

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments ​ The tables below present information about the Company’s assets that are measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019 and indicate the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize observable inputs such as quoted prices in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are either directly or indirectly observable, such as quoted prices for similar instruments in active markets, interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points in which there is little or no market data, which require the Company to develop its own assumptions for the asset or liability. ​ The Company’s investment portfolio may include fixed income securities that do not always trade on a daily basis. As a result, the pricing services used by the Company apply other available information as applicable through processes such as benchmark yields, benchmarking of like securities, sector groupings and matrix pricing to prepare valuations. In addition, model processes are used to assess interest rate impact and develop prepayment scenarios. These models take into consideration relevant credit information, perceived market movements, sector news and economic events. The inputs into these models may include benchmark yields, reported trades, broker-dealer quotes, issuer spreads and other relevant data. The Company validates the prices provided by its third-party pricing services by obtaining market values from other pricing sources and analyzing pricing data in certain instances. The Company also invests in certain reverse repurchase agreements which are collateralized by Government Securities and Obligations for an amount not less than 102% of their principal amount. The Company does not record an asset or liability for the collateral as the Company is not permitted to sell or re-pledge the collateral. The collateral has at least the prevailing credit rating of U.S. Government Treasuries and Agencies. The Company utilizes a third-party custodian to manage the exchange of funds and ensure the collateral received is maintained at 102% of the reverse repurchase agreements principal amount on a daily basis. ​ The following tables present the assets and liabilities the Company has measured at fair value on a recurring basis (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at Reporting Date Using ​ ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ March 31, 2020 ​ ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 215,790 ​ ​ $ 215,790 ​ $ — ​ $ — ​ Restricted cash: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ 2,221 ​ ​ ​ 2,221 ​ ​ — ​ ​ — ​ Convertible Note Hedges ​ ​ 15,847 ​ ​ ​ — ​ ​ — ​ ​ 15,847 ​ Total assets measured at fair value ​ $ 233,858 ​ ​ $ 218,011 ​ $ — ​ $ 15,847 ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note Hedge Warrants ​ $ 12,207 ​ ​ $ — ​ $ — ​ $ 12,207 ​ Total liabilities measured at fair value ​ $ 12,207 ​ ​ $ — ​ $ — ​ $ 12,207 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at Reporting Date Using ​ ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ December 31, 2019 ​ ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 139,190 ​ ​ $ 139,190 ​ $ — ​ $ — ​ Repurchase agreements ​ ​ 37,800 ​ ​ ​ 37,800 ​ ​ — ​ ​ — ​ Restricted cash: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 2,221 ​ ​ 2,221 ​ — ​ — ​ Convertible Note Hedges ​ ​ 31,366 ​ ​ ​ — ​ ​ — ​ ​ 31,366 ​ Total assets measured at fair value ​ $ 210,577 ​ ​ $ 179,211 ​ $ — ​ $ 31,366 ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note Hedge Warrants ​ $ 24,260 ​ ​ $ — ​ $ — ​ $ 24,260 ​ Total liabilities measured at fair value ​ $ 24,260 ​ ​ $ — ​ $ — ​ $ 24,260 ​ ​ There were no transfers between fair value measurement levels during each of the three months ended March 31, 2020 or 2019. ​ Cash equivalents, accounts receivable, related party accounts receivable, prepaid expenses and other current assets, accounts payable, related party accounts payable, accrued research and development costs, accrued expenses and other current liabilities, deferred revenue and current portion of operating lease obligations at March 31, 2020 and 2019 are carried at amounts that approximate fair value due to their short-term maturities. ​ Convertible Note Hedges and Note Hedge Warrants with Respect to 2022 Convertible Notes ​ The Company’s Convertible Note Hedges and the Note Hedge Warrants are recorded as derivative assets and liabilities, respectively, and are classified as Level 3 measurements under the fair value hierarchy. These derivatives are not actively traded and are valued using the Black-Scholes option-pricing model, which requires the use of subjective assumptions. Significant inputs used to determine the fair value as of March 31, 2020 included the price per share of the Company’s Class A Common Stock, expected terms of the derivative instruments, strike prices of the derivative instruments, risk-free interest rates, and expected volatility of the Company’s Class A Common Stock. Changes to these inputs could materially affect the valuation of the Convertible Note Hedges and Note Hedge Warrants. ​ The following inputs were used in the fair market valuation of the Convertible Note Hedges and Note Hedge Warrants as of March 31, 2020 and December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Year Ended ​ ​ ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ ​ ​ Convertible Note Hedge ​ Convertible Note Hedge ​ ​ Note Hedges ​ Warrants Note Hedges ​ Warrants Risk-free interest rate (1) ​ ​ 0.2 % ​ 0.3 % ​ 1.6 % ​ 1.6 % Expected term ​ 2.2 ​ 2.8 ​ ​ 2.5 ​ 3.0 ​ Stock price (2) ​ $ 10.09 ​ $ 10.09 ​ $ 13.31 ​ $ 13.31 ​ Strike price (3) ​ $ 14.51 ​ $ 18.82 ​ $ 14.51 ​ $ 18.82 ​ Common stock volatility (4) ​ ​ 52.4 % ​ 50.1 % ​ 49.1 % ​ 46.5 % Dividend yield (5) ​ — % — % — % — % (1) Based on U.S. Treasury yield curve, with terms commensurate with the expected terms of the Convertible Note Hedges and the Note Hedge Warrants. (2) The closing price of the Company’s Class A Common Stock on the last trading days of the quarters ended March 31, 2020 and December 31, 2019, respectively. (3) As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants. (4) Expected volatility based on historical volatility of the Company’s Class A Common Stock. (5) The Company has not paid and does not anticipate paying cash dividends on its shares of common stock in the foreseeable future; therefore, the expected dividend yield is assumed to be zero. ​ The Convertible Note Hedges and the Note Hedge Warrants are recorded at fair value at each reporting date and changes in fair value are recorded in other (expense) income, net within the Company’s condensed consolidated statements of operations. Gains and losses for these derivative financial instruments are presented separately in the Company’s condensed consolidated statements of cash flows. ​ The following table reflects the change in the Company’s Level 3 Convertible Note Hedges and Note Hedge Warrants from December 31, 2019 through March 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible ​ Note Hedge ​ ​ Note Hedges Warrants Balance at December 31, 2019 ​ $ 31,366 ​ $ (24,260) ​ Change in fair value, recorded as a component of (loss) gain on derivatives ​ ​ (15,519) ​ ​ 12,053 ​ Balance at March 31, 2020 ​ $ 15,847 ​ $ (12,207) ​ ​ Convertible Senior Notes ​ In June 2015, the Company issued approximately $335.7 million aggregate principal amount of its 2022 Convertible Notes. In August 2019, the Company issued $200.0 million aggregate principal amount of its 2024 Convertible Notes and $200.0 million aggregate principal amount of its 2026 Convertible Notes and used a portion of the proceeds from such issuances to repurchase $215.0 million aggregate principal amount of its 2022 Convertible Notes. The Company separately accounted for the liability and equity components of each of the 2022 Convertible Notes, 2024 Convertible Notes, and 2026 Convertible Notes by allocating the proceeds between the liability component and equity component (Note 8). The fair value of the respective convertible senior notes, which differs from their carrying value, is influenced by interest rates, the price of the Company’s Class A Common Stock and the volatility thereof, and the prices for the respective convertible senior notes observed in market trading, which are Level 2 inputs. ​ The estimated fair value of the 2022 Convertible Notes was approximately $124.7 million and approximately $141.3 million as of March 31, 2020 and December 31, 2019, respectively. The estimated fair value of the 2024 Convertible Notes was approximately $202.1 million and approximately $235.7 million as of March 31, 2020 and December 31, 2019, respectively. The estimated fair value of the 2026 Convertible Notes was approximately $202.4 million and approximately $240.1 million as of March 31, 2020 and December 31, 2019, respectively. ​ Capped Calls with Respect to 2024 Convertible Notes and 2026 Convertible Notes ​ Derivatives and Hedging ​

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Accrued Expenses and Other Current Liabilities	6. Accrued Expenses and Other Current Liabilities ​ Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2020 December 31, 2019 Salaries ​ $ 1,582 ​ $ 2,973 ​ Accrued vacation ​ ​ 3,007 ​ ​ 2,540 ​ Accrued incentive compensation ​ ​ 3,672 ​ ​ 11,760 ​ Other employee benefits ​ ​ 2,084 ​ ​ 1,260 ​ Professional fees ​ 2,036 ​ 1,421 ​ Accrued interest ​ 2,105 ​ 301 ​ Other ​ 4,233 ​ 10,210 ​ ​ ​ $ 18,719 ​ $ 30,465 ​ ​ ​ ​ ​ As of March 31, 2020, other accrued expenses of approximately $4.2 million included approximately $0.9 million related to unbilled drug product and finished goods manufacturing costs, approximately $0.3 million related to equipment for clinical studies, approximately $0.2 million related to franchise taxes, approximately $0.2 million related to facility services, and approximately $0.2 million related to public relations services. ​ As of December 31, 2019, other accrued expenses of approximately $10.2 million included approximately $4.1 million related to API batches yet to be invoiced, approximately $0.9 million related to activities associated with the Company’s move to the 100 Summer Street headquarters, approximately $0.6 million related to unbilled inventory, and approximately $0.2 million related to equipment for clinical studies. ​

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Leases	7. Leases ​ Effective January 1, 2019, the Company adopted ASC 842 using the optional transition method. The Company’s lease portfolio for the three months ended March 31, 2020 includes: leases for its current headquarters location, a data center colocation lease, vehicle leases for its salesforce representatives, and leases for computer and office equipment. ​ Lease cost is recognized on a straight-line basis over the lease term. The components of lease cost for the three months ended March 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Operating lease cost during period ​ $ 633 ​ $ 4,525 Short-term lease cost ​ ​ 372 ​ ​ 389 Total lease cost ​ $ 1,005 ​ $ 4,914 ​ ​ Supplemental cash flow information related to leases for the periods reported is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Right-of-use assets obtained in exchange for new operating lease upon adoption of ASC 842 (in thousands) ​ $ — ​ $ 88,299 ​ Cash paid for amounts included in the measurement of lease liabilities (in thousands) ​ ​ 43 ​ ​ 4,412 ​ Weighted-average remaining lease term of operating leases (in years) ​ ​ 10.0 ​ ​ 5.7 ​ Weighted-average discount rate of operating leases ​ ​ 5.8 % ​ 6.7 % ​ ​ ​ Future minimum lease payments under non-cancelable operating leases as of March 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ Operating ​ Lease ​ ​ Payments 2020 (1) ​ $ 1,102 2021 ​ ​ 3,128 2022 ​ ​ 3,129 2023 ​ ​ 3,065 2024 ​ 3,126 2025 and thereafter ​ 18,044 Total future minimum lease payments ​ ​ 31,594 Less: present value adjustment ​ ​ (8,072) Operating lease liabilities at March 31, 2020 ​ ​ 23,522 Less: current portion of operating lease liabilities ​ ​ (1,876) Operating lease liabilities, net of current portion ​ $ 21,646 (1) For the nine months ending December 31, 2020. ​ Summer Street Lease (current headquarters) ​ On June 11, 2019, the Company entered into a non-cancelable operating lease (the “Summer Street Lease”) with MA-100 Summer Street Owner, L.L.C. for approximately 39,000 square feet of office space on the 23 rd improvement allowance. The rent expense for the Summer Street Property, inclusive of the escalating rent payments and lease incentives, is recognized on a straight-line basis over the lease term. Additionally, the Summer Street Lease requires a letter of credit to secure the Company’s obligations under the lease agreement of approximately $1.0 million, which is collateralized by a money market account recorded as non-current restricted cash on the Company’s condensed consolidated balance sheets as of March 31, 2020 and December 31, 2019. ​ At lease inception, the Company recorded a right-of-use asset and a lease liability using an incremental borrowing rate of approximately 5.8%. At March 31, 2020, the balances of the right-of-use asset and operating lease liability were approximately $17.4 million and approximately $23.1 million, respectively. At December 31, 2019, the balances of the right-of-use asset and operating lease liability were approximately $17.7 million and approximately $22.8 million, respectively. ​ Lease cost related to the Summer Street Lease recorded during the three months ended March 31, 2020 was approximately $0.6 million. ​ Binney Street Lease (prior headquarters) ​ The Company rented office space at 301 Binney Street, Cambridge, Massachusetts (“Binney Street Property”) under a non-cancelable operating lease, entered into in January 2007, as amended (“Binney Street Lease”) through October 2019. The Binney Street Property previously served as the Company’s headquarters and was replaced by the Summer Street Property in October 2019, as discussed above. ​ Lease cost related to the Binney Street Lease recorded during the three months ended March 31, 2019 was approximately $2.6 million. ​ Data center colocation lease ​ The Company rents space for its data center at a colocation in Boston, Massachusetts under a non-cancelable operating lease (the “Data Center Lease”). The Data Center Lease includes a 4% annual rent escalation. The rent expense, inclusive of the escalating rent payments, is recognized on a straight-line basis over the lease term through August 2022. The Company recorded a right-of-use asset of approximately $0.6 million and a lease liability of approximately $0.6 million associated with the Data Center Lease upon adoption of ASC 842. The incremental borrowing rate for the outstanding Data Center Lease obligation upon adoption of ASC 842 was approximately 6.0%. During the three months ended March 31, 2019, the Company migrated its data management process to a cloud-based services system, rendering its current data center technology and assets obsolete. As a result, the Company considered the right-of-use asset associated with the Data Center Lease to be fully impaired. The Company recorded a charge of approximately $0.5 million to selling, general, and administrative expenses on its condensed consolidated statement of operations as a result of the impairment during the three months ended March 31, 2019. ​ At both March 31, 2020 and December 31, 2019, the lease liability associated with the Data Center Lease was approximately $0.4 million. ​ Costs related to the Data Center Lease were insignificant for each of the three months ended March 31, 2020 and 2019. ​ Vehicle fleet leases ​ During April 2018, the Company entered into a master services agreement containing 12-month leases (the “2018 Vehicle Leases”) for vehicles within its fleet for its field-based sales force and medical science liaisons. These leases are classified as short-term in accordance with the practical expedient in ASC 842. The 2018 Vehicle Leases expire at varying times beginning in June 2019, with a monthly ​ Lease cost related to the 2018 Vehicle Leases was approximately $0.4 million for each of the three months ended March 31, 2020 and 2019.

Notes Payable

Notes Payable	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Notes Payable	8. Notes Payable ​ 2.25% Convertible Senior Notes due 2022 ​ In June 2015, the Company issued approximately $335.7 million aggregate principal amount of the 2022 Convertible Notes. The Company received net proceeds of approximately $324.0 million from the sale of the 2022 Convertible Notes, after deducting fees and expenses of approximately $11.7 million. The Company used approximately $21.1 million of the net proceeds from the sale of the 2022 Convertible Notes to pay the net cost of the Convertible Note Hedges (after such cost was partially offset by the proceeds to the Company from the sale of the Note Hedge Warrants), as described below. ​ The 2022 Convertible Notes are governed by an indenture (the “2022 Indenture”) between the Company and U.S. Bank National Association, as trustee (the “Trustee”). The 2022 Convertible Notes are senior unsecured obligations and bear cash interest at the annual rate of 2.25%, payable on June 15 and December 15 of each year, which began on December 15, 2015. The 2022 Convertible Notes will mature on June 15, 2022, unless earlier converted or repurchased. The Company may settle conversions of the 2022 Convertible Notes through payment or delivery, as the case may be, of cash, shares of Class A Common Stock of the Company or a combination of cash and shares of Class A Common Stock, at the Company’s option (subject to, and in accordance with, the settlement provisions of the 2022 Indenture). The initial conversion rate for the 2022 Convertible Notes was 60.3209 shares of Class A Common Stock (subject to adjustment as provided for in the 2022 Indenture) per $1,000 principal amount of the 2022 Convertible Notes, which was equal to an initial conversion price of approximately $16.58 per share and 20,249,665 shares. ​ In connection with the Separation in April 2019, the conversion rate under the 2022 Indenture was adjusted to equal 68.9172 shares of Ironwood Class A Common Stock per $1,000 principal amount of the 2022 Convertible Notes, which is equal to an adjusted conversion price of approximately $14.51 per share and 23,135,435 shares. ​ Holders of the 2022 Convertible Notes may convert their 2022 Convertible Notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2021 in multiples of $1,000 principal amount, only under the following circumstances: ​ ● during any calendar quarter commencing after the calendar quarter ending on September 30, 2015 (and only during such calendar quarter), if the last reported sale price of the Company’s Class A Common Stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price for the 2022 Convertible Notes on each applicable trading day; ​ ● during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the 2022 Indenture) per $1,000 principal amount of the 2022 Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s Class A Common Stock and the conversion rate for the 2022 Convertible Notes on each such trading day; or ​ ● upon the occurrence of specified corporate events described in the 2022 Indenture. ​ On or after December 15, 2021, until the close of business on the second scheduled trading day immediately preceding June 15, 2022, holders may convert their 2022 Convertible Notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances. ​ If a make-whole fundamental change, as described in the 2022 Indenture, occurs and a holder elects to convert its 2022 Convertible Notes in connection with such make-whole fundamental change, such holder may be entitled to an increase in the conversion rate as described in the 2022 Indenture. The Company may not redeem the 2022 Convertible Notes prior to the maturity date and no “sinking fund” is provided for by the 2022 Convertible Notes, which means that the Company is not required to periodically redeem or retire the 2022 Convertible Notes. Upon the occurrence of certain fundamental changes involving the Company, holders of the 2022 Convertible Notes may require the Company to repurchase for cash all or part of their 2022 Convertible Notes at a repurchase price equal to 100% of the principal amount of the 2022 Convertible Notes to be repurchased, plus accrued and unpaid interest. ​ The 2022 Indenture does not contain any financial covenants or restrict the Company’s ability to repurchase the Company’s securities, pay dividends or make restricted payments in the event of a transaction that substantially increases the Company’s level of indebtedness. The 2022 Indenture provides for customary events of default. In the case of an event of default with respect to the 2022 Convertible Notes arising from specified events of bankruptcy or insolvency, all outstanding 2022 Convertible Notes will become due and payable immediately without further action or notice. If any other event of default with respect to the 2022 Convertible Notes under the 2022 Indenture occurs or is continuing, the Trustee or holders of at least 25% in aggregate principal amount of the then outstanding 2022 Convertible Notes may declare the principal amount of the 2022 Convertible Notes to be immediately due and payable. Notwithstanding the foregoing, the 2022 Indenture provides that, upon the Company’s election, and for up to 180 days, the sole remedy for an event of default relating to certain failures by the Company to comply with certain reporting covenants in the 2022 Indenture consists exclusively of the right to receive additional interest on the 2022 Convertible Notes. ​ In accordance with accounting guidance for debt with conversion and other options, the Company separately accounted for the liability and equity components of the 2022 Convertible Notes by allocating the proceeds between the liability component and the embedded conversion option, or equity component, due to the Company’s ability to settle the 2022 Convertible Notes in cash, its Class A Common Stock, or a combination of cash and Class A Common Stock at the option of the Company. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The allocation was performed in a manner that reflected the Company’s non-convertible debt borrowing rate for similar debt. The equity component of the 2022 Convertible Notes was recognized as a debt discount and represents the difference between the gross proceeds from the issuance of the 2022 Convertible Notes and the fair value of the liability component of the 2022 Convertible Notes on their respective dates of issuance. The excess of the principal amount of the liability component over its carrying amount, or debt discount, is amortized to interest expense using the effective interest method over seven years, or the expected life of the 2022 Convertible Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. ​ In connection with the issuance of the 2024 Convertible Notes and the 2026 Convertible Notes in August 2019, the Company repurchased $215.0 million aggregate principal amount of the 2022 Convertible Notes. The 2022 Convertible Notes were repurchased at a premium totaling approximately $227.3 million. The Company recognized a loss on extinguishment of debt of approximately $23.4 million during the year ended December 31, 2019 related to the premium and proportional write-off of the 2022 Convertible Notes unamortized debt issuance costs and unamortized debt discount. Additionally, the repurchase resulted in a reduction to additional paid-in capital of approximately $27.0 million during the year ended December 31, 2019 related to the equity component of the 2022 Convertible Notes. ​ 0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 ​ In August 2019, the Company issued $200.0 million aggregate principal amount of the 2024 Convertible Notes and $200.0 million aggregate principal amount of the 2026 Convertible Notes. The Company received net proceeds of approximately $391.0 million from the sale of the 2024 Convertible Notes and 2026 Convertible Notes, after deducting fees and expenses of approximately $9.0 million. The Company used approximately $25.2 million of the net proceeds from the sale of the 2024 Convertible Notes and 2026 Convertible Notes to pay the cost of the Capped Calls, as described below. For purposes of this section, “Notes” refer to the 2024 Convertible Notes and the 2026 Convertible Notes, collectively. ​ approximately $13.39 per share, representing a conversion premium of approximately 37.5% above the last reported sale price of Class A Common Stock of $9.74 per share on August 7, 2019. ​ ​ ● during any calendar quarter commencing after the calendar quarter ending on December 31, 2019 (and only during such calendar quarter), if the last reported sale price of the Company’s Class A Common Stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price for the Notes on each applicable trading day; ​ ● during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in each Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of Class A Common Stock and the conversion rate for the Notes on each such trading day; or ​ ● upon the occurrence of specified corporate events described in each Indenture. ​ ​ ​ ​ In accordance with accounting guidance for debt with conversion and other options, the Company separately accounted for the liability and equity components of the 2024 Convertible Notes and the 2026 Convertible Notes by allocating the proceeds between the liability components and the embedded conversion options, or equity components, due to the Company’s ability to settle the 2024 Convertible Notes and the 2026 Convertible Notes in cash, its Class A Common Stock, or a combination of cash and Class A Common Stock at the option of the Company. The carrying amount of the respective liability components were calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The allocation was performed in a manner that reflected the Company’s non-convertible debt borrowing rate for similar debt. The respective equity components of the 2024 Convertible Notes and the 2026 Convertible Notes were recognized as a debt discount and represent the difference between the gross proceeds from the issuance of the 2024 Convertible Notes and 2026 Convertible Notes and the fair value of the liability of the 2024 Convertible Notes and 2026 Convertible Notes on their respective dates of issuance. The excess of the principal amount of the liability component over its carrying amount, or debt discount, is amortized to interest expense using the effective interest method over approximately five ​ The Company’s outstanding balances for the convertible senior notes as of March 31, 2020 and December 31, 2019 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2020 ​ December 31, 2019 ​ Liability component: ​ ​ ​ ​ ​ ​ Principal: ​ ​ ​ ​ ​ ​ 2022 Convertible Notes ​ $ 120,699 ​ $ 120,699 ​ 2024 Convertible Notes ​ ​ 200,000 ​ ​ 200,000 ​ 2026 Convertible Notes ​ ​ 200,000 ​ ​ 200,000 ​ Less: unamortized debt discount ​ ​ (99,631) ​ ​ (104,700) ​ Less: unamortized debt issuance costs ​ ​ (7,659) ​ ​ (8,005) ​ Net carrying amount ​ $ 413,409 ​ $ 407,994 ​ Equity component: ​ ​ ​ ​ ​ ​ ​ 2022 Convertible Notes ​ ​ 19,807 ​ ​ 19,807 ​ 2024 Convertible Notes ​ ​ 41,152 ​ ​ 41,152 ​ 2026 Convertible Notes ​ ​ 51,350 ​ ​ 51,350 ​ Total equity component ​ $ 112,309 ​ $ 112,309 ​ ​ ​ In connection with the issuance of the 2022 Convertible Notes, the Company incurred approximately $11.7 million of debt issuance costs, which primarily consisted of initial purchasers’ discounts and legal and other professional fees. The Company allocated these costs to the liability and equity components based on the allocation of the proceeds. The portion of these costs allocated to the equity components totaling approximately $4.0 million were recorded as a reduction to additional paid-in capital upon issuance. The portion of these costs allocated to the liability components totaling approximately $7.7 million were recorded as a reduction in the carrying value of the debt on the condensed consolidated balance sheet and are amortized to interest expense using the effective interest method over the expected life of the 2022 Convertible Notes. In connection with the partial repurchase of the 2022 Convertible Notes, the Company recorded a loss on extinguishment of debt of approximately $23.4 million, of which approximately $2.8 million related to the initial debt issuance costs during the year ended December 31, 2019. ​ The Company determined the expected life of the 2022 Convertible Notes was equal to their seven-year term. From the date of the partial repurchase of the 2022 Convertible Notes in August 2019 through March 31, 2020, the effective interest rate on the liability component of the 2022 Convertible Notes was 9.5%. ​ In connection with the issuance of the 2024 Convertible Notes and the 2026 Convertible Notes, the Company incurred approximately $9.0 million of debt issuance costs, which primarily consisted of initial purchaser’s discounts and legal and other professional fees. The Company allocated these costs to the liability and equity components based on the allocation of the proceeds. The portion of these costs allocated to the equity components totaling approximately $2.1 million were recorded as a reduction to additional paid-in capital. The portion of these costs allocated to the liability components totaling approximately $6.9 million were recorded as a reduction in the carrying value of the debt on the condensed consolidated balance sheet and are amortized to interest expense using the effective interest method over the expected life of the 2024 Convertible Notes and the 2026 Convertible Notes. ​ The Company determined the expected life of the 2024 Convertible Notes and the 2026 Convertible Notes was equal to their approximately five components of the 2024 Convertible Notes and the 2026 Convertible Notes for the period from the date of issuance through March 31, 2020 was 6.1% and 6.5%, respectively. ​ The following table sets forth total interest expense recognized related to convertible senior notes during the three months ended March 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ ​ March 31, ​ ​ ​ 2020 2019 Contractual interest expense ​ $ 1,805 ​ $ 1,888 ​ ​ Amortization of debt issuance costs ​ ​ 346 ​ ​ 272 ​ ​ Amortization of debt discount ​ ​ 5,069 ​ ​ 4,075 ​ ​ Total interest expense ​ $ 7,220 ​ $ 6,235 ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 (1) ​ $ 7,216 ​ 2021 ​ ​ 7,216 ​ 2022 ​ ​ 126,556 ​ 2023 ​ ​ 4,500 ​ 2024 ​ ​ 203,750 ​ 2025 ​ ​ 3,000 ​ 2026 and Thereafter ​ ​ 201,500 ​ Total future minimum payments under the convertible senior notes ​ 553,738 ​ Less: amounts representing interest ​ ​ (33,039) ​ Less: unamortized debt discount ​ ​ (99,631) ​ Less: unamortized debt issuance costs ​ ​ (7,659) ​ Convertible senior notes balance ​ $ 413,409 ​ (1) For the nine months ending December 31, 2020. ​ Convertible Note Hedge and Note Hedge Warrant Transactions with Respect to 2022 Convertible Notes ​ To minimize the impact of potential dilution to the Company’s Class A common stockholders upon conversion of the 2022 Convertible Notes, the Company entered into the Convertible Note Hedges covering 20,249,665 shares of the Company’s Class A Common Stock in connection with the issuance of the 2022 Convertible Notes. The Convertible Note Hedges had an initial exercise price of $16.58 per share, subject to adjustment upon the occurrence of certain corporate events or transactions, and are exercisable if the 2022 Convertible Notes are converted. In connection with the adjustment to the conversion rate of the 2022 Convertible Notes related to the Separation in April 2019, the exercise price of the Convertible Note Hedges was adjusted to $14.51 per share and the number of shares underlying the Convertible Note Hedges was increased to 23,135,435 shares. If upon conversion of the 2022 Convertible Notes, the price of the Company’s Class A Common Stock is above the exercise price of the Convertible Note Hedges, the counterparties are obligated to deliver shares of the Company’s Class A Common Stock and/or cash with an aggregate value approximately equal to the difference between the price of the Company’s Class A Common Stock at the conversion date and the exercise price, multiplied by the number of shares of the Company’s Class A Common Stock related to the Convertible Note Hedge being exercised. ​ Concurrently with entering into the Convertible Note Hedges, the Company sold Note Hedge Warrants to the Convertible Note Hedge counterparties to acquire 20,249,665 shares of the Company’s Class A Common Stock, subject to customary anti-dilution adjustments. The strike price of the Note Hedge Warrants was initially $21.50 per share, subject to adjustment, and such warrants are exercisable over the 150 trading day period beginning on September 15, 2022. In connection with the Separation in April 2019, the exercise price was adjusted to $18.82 per share and the number of shares underlying the Note Hedge Warrants was increased to 23,135,435 ​ The Convertible Note Hedges and the Note Hedge Warrants are separate transactions entered into by the Company and are not part of the terms of the 2022 Convertible Notes. Holders of the Convertible Note Hedges and the Note Hedge Warrants do not have any rights with respect to the 2022 Convertible Notes. The Company paid approximately $91.9 million for the Convertible Note Hedges and recorded this amount as a long-term asset on its condensed consolidated balance sheet. The Company received approximately $70.8 million for the Note Hedge Warrants and recorded this amount as a long-term liability, resulting in a net cost to the Company of approximately $21.1 million. ​ In August 2019, concurrently with the repurchase of $215.0 million aggregate principal amount of the 2022 Convertible Notes, the Company terminated the respective portion of the Convertible Note Hedges and Note Hedge Warrants. The Company received approximately $3.2 million of termination payments from the counterparties of the Convertible Note Hedges and Note Hedge Warrants. ​ The Convertible Note Hedges and Note Hedge Warrants are accounted for as derivative assets and liabilities, respectively, in accordance with ASC 815. ​ Capped Calls with Respect to 2024 Convertible Notes and 2026 Convertible Notes ​ ​ ​ ​

Employee Stock Benefit Plans

Employee Stock Benefit Plans	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Employee Stock Benefit Plans	9. Employee Stock Benefit Plans ​ The Company has several share-based compensation plans under which stock options, restricted stock awards, restricted stock units, and other share-based awards are available for grant to employees, officers, directors and consultants of the Company. ​ The following table summarizes share-based compensation expense (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Research and development ​ $ 1,396 ​ $ 2,918 ​ Selling, general and administrative ​ 4,968 ​ ​ 10,499 ​ Restructuring expenses ​ — ​ 517 ​ ​ ​ $ 6,364 ​ $ 13,934 ​ ​ In February 2019, following further analysis of the Company’s strategy and core business needs, and in an effort to further strengthen the operational efficiency of the organization, the Company commenced a reduction in workforce by approximately 35 employees, primarily based in the home office. Certain share-based payment awards were modified in connection with the reduction in workforce. As a result of the modifications, the Company recorded share-based compensation expense of approximately $0.5 million to restructuring expenses for the three months ended March 31, 2019. ​ In connection with certain other modifications of share-based payment awards for the three months ended March 31, 2020 and 2019, the Company recognized an insignificant amount and approximately

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Related Party Transactions	10. Related Party Transactions ​ Under the collaboration agreement, the Company and Allergan equally support the development and commercialization of linaclotide (Note 4). Amounts due to and due from Allergan are reflected as related party accounts payable and related party accounts receivable, respectively. These balances are reported net of any balances due to or from the related party. As of March 31, 2020 and December 31, 2019, the Company had approximately $73.4 million and approximately $106.0 million, respectively, in related party accounts receivable, net of related party accounts payable, associated with Allergan. ​ The Company has and currently obtains health insurance services for its employees from an insurance provider whose President and Chief Executive Officer became a member of the Company’s Board of Directors in April 2016. The Company paid approximately $2.4 million and approximately $2.5 million in insurance premiums to this insurance provider during the three months ended March 31, 2020 and 2019, respectively. At both March 31, 2020 and December 31, 2019, the Company had no ​ In connection with the Separation, the Company executed certain contracts with Cyclerion whose President became a member of the Company’s Board of Directors in April 2019 (Note 2). As of March 31, 2020, the Company had an insignificant amount of accounts receivable and approximately $1.1 million of accounts payable due from and to Cyclerion, respectively. As of December 31, 2019, the Company had an insignificant amount of accounts receivable and approximately $1.5 million of accounts payable due from and to Cyclerion, respectively. The transition services agreements with Cyclerion terminated on March 31, 2020.

Workforce Reduction

Workforce Reduction	3 Months Ended
	Mar. 31, 2020
Disclosure Text Block
Workforce Reduction	11. Workforce Reduction ​ On February 7, 2019, following analysis of the Company’s strategy and core business needs, and in an effort to further strengthen the operational efficiency of the organization, the Company commenced a reduction in workforce by approximately 35 employees, primarily based in the home office. During the three months ended March 31, 2019, the Company substantially completed the implementation of this reduction in workforce and, in accordance with ASC 420, Exit or Disposal Cost Obligations ​ During the three months ended March 31, 2020 and 2019, the Company recorded no restructuring expenses and approximately $3.3 million in restructuring expenses, respectively. At March 31, 2020 and December 31, 2019, the Company had an insignificant amount and approximately $0.2 million in accrued restructuring costs remaining, respectively.

Nature of Business (Policies)

Nature of Business (Policies)	3 Months Ended
	Mar. 31, 2020
Policy Text Blocks
Basis of Presentation	Basis of Presentation ​ The accompanying condensed consolidated financial statements and the related disclosures are unaudited and have been prepared in accordance with accounting principles generally accepted in the U.S. Additionally, certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the Securities and Exchange Commission on February 13, 2020 (the “2019 Annual Report on Form 10-K”). ​ The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all normal recurring adjustments considered necessary for a fair presentation of the Company’s financial position as of March 31, 2020, and the results of its operations for the three months ended March 31, 2020 and 2019, its statements of stockholders’ deficit for the three months ended March 31, 2020 and 2019, and its cash flows for the three months ended March 31, 2020 and 2019. The results of operations for the three months ended March 31, 2020 and 2019 are not necessarily indicative of the results that may be expected for the full year or any other subsequent interim period. ​ The Company has presented its sGC business as discontinued operations in its condensed consolidated financial statements for all periods presented. The historical financial statements and footnotes have been recast accordingly (Note 2). For periods following the Separation, the Company continues to report financial results under one business segment.
Principles of Consolidation	Principles of Consolidation ​ The accompanying condensed consolidated financial statements include the accounts of Ironwood and its wholly-owned subsidiaries as of March 31, 2020, Ironwood Pharmaceuticals Securities Corporation and Ironwood Pharmaceuticals GmbH. Cyclerion was a wholly-owned subsidiary until it became an independent, publicly-traded company on April 1, 2019. All intercompany transactions and balances are eliminated in consolidation.
Use of Estimates	Use of Estimates ​ The preparation of condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles requires the Company’s management to make estimates and judgments that may 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. On an ongoing basis, the Company’s management evaluates its estimates, judgments and methodologies. Significant estimates and assumptions in the condensed consolidated financial statements include those related to revenue recognition; accounts receivable; inventory valuation and related reserves; useful lives of long-lived assets; impairment of long-lived assets, including goodwill; valuation procedures for right-of-use assets and operating lease liabilities; valuation procedures for the issuance and repurchase of convertible notes; losses related to discontinued operations; fair value of derivatives; balance sheet classification of convertible notes; income taxes, including the valuation allowance for deferred tax assets; research and development expenses; contingencies and share-based compensation. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ materially from these estimates under different assumptions or conditions. Changes in estimates are reflected in reported results in the period in which they become known.
Reclassifications of Prior Period Financial Statements	Reclassifications of Prior Period Financial Statements ​ Certain prior period financial statement items have been reclassified to conform to current period presentation. The Company has presented its sGC business as discontinued operations in its condensed consolidated financial statements for prior periods presented. The historical financial statements and footnotes have been recast accordingly.
New Accounting Pronouncements	New Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Except as set forth below, the Company did not adopt any new accounting pronouncements during the three months ended March 31, 2020 that had a material effect on its condensed consolidated financial statements. ​ In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Date Codification Improvements to Topic 326, Financial Instruments—Credit Losses Financial Instruments—Credit Losses (Topic 326) and Leases (Topic 842): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842) Financial Instruments—Credit Losses ​ In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirement for Fair Value Measurement In August 2018, the FASB issued ASU No. 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 (a consensus of the FASB Emerging Issues Task Force) In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , No other accounting standards known by the Company to be applicable to it that have been issued by the FASB or other standard-setting bodies and that do not require adoption until a future date are expected to have a material impact on the Company’s condensed consolidated financial statements upon adoption.

Cyclerion Separation (Tables)

Cyclerion Separation (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Summary of assets and liabilities transferred in separation	The transfer of assets and liabilities to Cyclerion was effected through a contribution in accordance with the separation agreement as summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 1, 2019 ​ Assets: ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 1,169 ​ Property and equipment, net ​ ​ 10,241 ​ Other assets ​ ​ 21 ​ ​ ​ $ 11,431 ​ Liabilities: ​ ​ ​ ​ Accrued research and development costs ​ $ 5,673 ​ Accrued expenses and other current liabilities ​ ​ 3,149 ​ ​ ​ $ 8,822 ​ Net Assets Transferred to Cyclerion ​ $ 2,609 ​ ​ In addition, the Company received approximately $1.3 million during the year ended December 31, 2019 associated with tenant improvement reimbursement provisions related to the Cyclerion lease in accordance with the separation agreement. ​
Summary of the discontinued operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2020 2019 Costs and expenses: ​ ​ ​ ​ ​ ​ ​ Research and development ​ $ — $ 21,792 ​ Selling, general and administrative ​ ​ — ​ 15,646 ​ Net loss from discontinued operations ​ $ — ​ $ 37,438 ​ ​

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Schedule of potentially dilutive securities that have been excluded from computation of diluted weighted average shares outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Options to purchase Class A Common Stock ​ 15,647 24,080 Shares subject to repurchase 182 32 Time-vesting restricted stock units ​ 4,945 ​ 3,641 ​ Performance-based restricted stock units ​ 543 ​ — ​ Shares subject to issuance under Employee Stock Purchase Plan ​ 105 ​ 125 ​ Note Hedge Warrants ​ 8,318 ​ 20,250 ​ 2022 Convertible Notes ​ 8,318 ​ 20,250 ​ 2024 Convertible Notes ​ 14,934 ​ — ​ 2026 Convertible Notes ​ 14,934 ​ — ​ ​ 67,926 68,378

Collaboration, License, Co-Pr_2

Collaboration, License, Co-Promotion and Other Commercial Agreements (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Schedule of revenue attributable to transactions from collaboration and license arrangements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ Collaborative Arrangements Revenue ​ 2020 2019 ​ Linaclotide Collaboration Agreements: ​ ​ ​ ​ ​ ​ ​ Allergan (North America) ​ $ 71,692 ​ $ 64,785 ​ Allergan (Europe and other) ​ ​ 643 ​ ​ 420 ​ AstraZeneca (China, including Hong Kong and Macau) ​ ​ 332 ​ — ​ Astellas (Japan) ​ ​ 479 ​ — ​ Co-Promotion and Other Agreements: ​ ​ ​ ​ ​ ​ ​ Alnylam (GIVLAARI) ​ ​ 945 ​ ​ — ​ Other ​ ​ 354 ​ ​ 947 ​ Total collaborative arrangements revenue ​ $ 74,445 ​ $ 66,152 ​ Sale of API Linaclotide License Agreements: ​ ​ ​ ​ ​ ​ ​ Astellas (Japan) ​ $ — ​ $ 2,575 ​ AstraZeneca (China, including Hong Kong and Macau) ​ ​ 5,498 ​ ​ — ​ Other ​ ​ — ​ ​ 3 ​ Total sale of API ​ $ 5,498 ​ $ 2,578 ​
Allergan
Table Text Blocks
Schedule of revenue attributable to transactions from collaboration and license arrangements	The Company recognized collaborative arrangements revenue from the Allergan collaboration agreement for North America during the three months ended March 31, 2020 and 2019 as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Collaborative arrangements revenue related to sales of LINZESS in the U.S. ​ $ 71,142 ​ $ 64,293 ​ Royalty revenue ​ 550 ​ 492 ​ Total collaborative arrangements revenue ​ $ 71,692 ​ $ 64,785 ​
Schedule of amount recorded by the Company for share of net loss related to collaborative arrangement	The following table presents the amounts recorded by the Company for commercial efforts related to LINZESS in the U.S. in the three months ended March 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Collaborative arrangements revenue related to sales of LINZESS in the U.S. (1) ​ $ 71,142 ​ $ 64,293 ​ Selling, general and administrative costs incurred by the Company (1) ​ (8,674) ​ (10,277) ​ The Company’s share of net profit ​ $ 62,468 ​ $ 54,016 ​ (1) Includes only collaborative arrangements revenue or selling, general and administrative costs attributable to the cost-sharing arrangement with Allergan. Excludes approximately $0.2 million and approximately $0.5 million for the three months ended March 31, 2020 and 2019, respectively, related to patent prosecution and patent litigation costs recognized in connection with the collaboration agreement with Allergan for North America. ​

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Schedule of assets and liabilities measured at fair value on a recurring basis	The following tables present the assets and liabilities the Company has measured at fair value on a recurring basis (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at Reporting Date Using ​ ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ March 31, 2020 ​ ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 215,790 ​ ​ $ 215,790 ​ $ — ​ $ — ​ Restricted cash: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ ​ 2,221 ​ ​ ​ 2,221 ​ ​ — ​ ​ — ​ Convertible Note Hedges ​ ​ 15,847 ​ ​ ​ — ​ ​ — ​ ​ 15,847 ​ Total assets measured at fair value ​ $ 233,858 ​ ​ $ 218,011 ​ $ — ​ $ 15,847 ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note Hedge Warrants ​ $ 12,207 ​ ​ $ — ​ $ — ​ $ 12,207 ​ Total liabilities measured at fair value ​ $ 12,207 ​ ​ $ — ​ $ — ​ $ 12,207 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements at Reporting Date Using ​ ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ December 31, 2019 ​ ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 139,190 ​ ​ $ 139,190 ​ $ — ​ $ — ​ Repurchase agreements ​ ​ 37,800 ​ ​ ​ 37,800 ​ ​ — ​ ​ — ​ Restricted cash: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ 2,221 ​ ​ 2,221 ​ — ​ — ​ Convertible Note Hedges ​ ​ 31,366 ​ ​ ​ — ​ ​ — ​ ​ 31,366 ​ Total assets measured at fair value ​ $ 210,577 ​ ​ $ 179,211 ​ $ — ​ $ 31,366 ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note Hedge Warrants ​ $ 24,260 ​ ​ $ — ​ $ — ​ $ 24,260 ​ Total liabilities measured at fair value ​ $ 24,260 ​ ​ $ — ​ $ — ​ $ 24,260 ​ ​
Schedule of assumptions used in fair market valuations	The following inputs were used in the fair market valuation of the Convertible Note Hedges and Note Hedge Warrants as of March 31, 2020 and December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Year Ended ​ ​ ​ March 31, ​ December 31, ​ ​ 2020 ​ 2019 ​ ​ ​ Convertible Note Hedge ​ Convertible Note Hedge ​ ​ Note Hedges ​ Warrants Note Hedges ​ Warrants Risk-free interest rate (1) ​ ​ 0.2 % ​ 0.3 % ​ 1.6 % ​ 1.6 % Expected term ​ 2.2 ​ 2.8 ​ ​ 2.5 ​ 3.0 ​ Stock price (2) ​ $ 10.09 ​ $ 10.09 ​ $ 13.31 ​ $ 13.31 ​ Strike price (3) ​ $ 14.51 ​ $ 18.82 ​ $ 14.51 ​ $ 18.82 ​ Common stock volatility (4) ​ ​ 52.4 % ​ 50.1 % ​ 49.1 % ​ 46.5 % Dividend yield (5) ​ — % — % — % — % (1) Based on U.S. Treasury yield curve, with terms commensurate with the expected terms of the Convertible Note Hedges and the Note Hedge Warrants. (2) The closing price of the Company’s Class A Common Stock on the last trading days of the quarters ended March 31, 2020 and December 31, 2019, respectively. (3) As per the respective agreements for the Convertible Note Hedges and Note Hedge Warrants. (4) Expected volatility based on historical volatility of the Company’s Class A Common Stock. (5) The Company has not paid and does not anticipate paying cash dividends on its shares of common stock in the foreseeable future; therefore, the expected dividend yield is assumed to be zero. ​
Schedule of the change in Level 3 convertible note derivatives	The following table reflects the change in the Company’s Level 3 Convertible Note Hedges and Note Hedge Warrants from December 31, 2019 through March 31, 2020 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible ​ Note Hedge ​ ​ Note Hedges Warrants Balance at December 31, 2019 ​ $ 31,366 ​ $ (24,260) ​ Change in fair value, recorded as a component of (loss) gain on derivatives ​ ​ (15,519) ​ ​ 12,053 ​ Balance at March 31, 2020 ​ $ 15,847 ​ $ (12,207) ​

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2020 December 31, 2019 Salaries ​ $ 1,582 ​ $ 2,973 ​ Accrued vacation ​ ​ 3,007 ​ ​ 2,540 ​ Accrued incentive compensation ​ ​ 3,672 ​ ​ 11,760 ​ Other employee benefits ​ ​ 2,084 ​ ​ 1,260 ​ Professional fees ​ 2,036 ​ 1,421 ​ Accrued interest ​ 2,105 ​ 301 ​ Other ​ 4,233 ​ 10,210 ​ ​ ​ $ 18,719 ​ $ 30,465 ​

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Schedule of components of lease cost and supplemental cash flow information	Lease cost is recognized on a straight-line basis over the lease term. The components of lease cost for the three months ended March 31, 2020 and 2019 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Operating lease cost during period ​ $ 633 ​ $ 4,525 Short-term lease cost ​ ​ 372 ​ ​ 389 Total lease cost ​ $ 1,005 ​ $ 4,914 ​ ​ Supplemental cash flow information related to leases for the periods reported is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2020 ​ 2019 Right-of-use assets obtained in exchange for new operating lease upon adoption of ASC 842 (in thousands) ​ $ — ​ $ 88,299 ​ Cash paid for amounts included in the measurement of lease liabilities (in thousands) ​ ​ 43 ​ ​ 4,412 ​ Weighted-average remaining lease term of operating leases (in years) ​ ​ 10.0 ​ ​ 5.7 ​ Weighted-average discount rate of operating leases ​ ​ 5.8 % ​ 6.7 % ​ ​
Schedule of future minimum lease payments under non-cancelable operating leases	Future minimum lease payments under non-cancelable operating leases as of March 31, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ Operating ​ Lease ​ ​ Payments 2020 (1) ​ $ 1,102 2021 ​ ​ 3,128 2022 ​ ​ 3,129 2023 ​ ​ 3,065 2024 ​ 3,126 2025 and thereafter ​ 18,044 Total future minimum lease payments ​ ​ 31,594 Less: present value adjustment ​ ​ (8,072) Operating lease liabilities at March 31, 2020 ​ ​ 23,522 Less: current portion of operating lease liabilities ​ ​ (1,876) Operating lease liabilities, net of current portion ​ $ 21,646 (1) For the nine months ending December 31, 2020.

Notes Payable (Tables)

Notes Payable (Tables)	3 Months Ended	9 Months Ended
	Mar. 31, 2020	Sep. 30, 2019
Table Text Blocks
Schedule of outstanding Convertible Note	The Company’s outstanding balances for the convertible senior notes as of March 31, 2020 and December 31, 2019 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2020 ​ December 31, 2019 ​ Liability component: ​ ​ ​ ​ ​ ​ Principal: ​ ​ ​ ​ ​ ​ 2022 Convertible Notes ​ $ 120,699 ​ $ 120,699 ​ 2024 Convertible Notes ​ ​ 200,000 ​ ​ 200,000 ​ 2026 Convertible Notes ​ ​ 200,000 ​ ​ 200,000 ​ Less: unamortized debt discount ​ ​ (99,631) ​ ​ (104,700) ​ Less: unamortized debt issuance costs ​ ​ (7,659) ​ ​ (8,005) ​ Net carrying amount ​ $ 413,409 ​ $ 407,994 ​ Equity component: ​ ​ ​ ​ ​ ​ ​ 2022 Convertible Notes ​ ​ 19,807 ​ ​ 19,807 ​ 2024 Convertible Notes ​ ​ 41,152 ​ ​ 41,152 ​ 2026 Convertible Notes ​ ​ 51,350 ​ ​ 51,350 ​ Total equity component ​ $ 112,309 ​ $ 112,309 ​ ​
Schedule of interest expense related to Convertible Notes	The following table sets forth total interest expense recognized related to convertible senior notes during the three months ended March 31, 2020 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ ​ March 31, ​ ​ ​ 2020 2019 Contractual interest expense ​ $ 1,805 ​ $ 1,888 ​ ​ Amortization of debt issuance costs ​ ​ 346 ​ ​ 272 ​ ​ Amortization of debt discount ​ ​ 5,069 ​ ​ 4,075 ​ ​ Total interest expense ​ $ 7,220 ​ $ 6,235 ​ ​
Schedule of future minimum payments details of debt	​ ​ ​ ​ ​ ​ 2020 (1) ​ $ 7,216 ​ 2021 ​ ​ 7,216 ​ 2022 ​ ​ 126,556 ​ 2023 ​ ​ 4,500 ​ 2024 ​ ​ 203,750 ​ 2025 ​ ​ 3,000 ​ 2026 and Thereafter ​ ​ 201,500 ​ Total future minimum payments under the convertible senior notes ​ 553,738 ​ Less: amounts representing interest ​ ​ (33,039) ​ Less: unamortized debt discount ​ ​ (99,631) ​ Less: unamortized debt issuance costs ​ ​ (7,659) ​ Convertible senior notes balance ​ $ 413,409 ​ (1) For the nine months ending December 31, 2020.	Future minimum payments under the convertible senior notes as of March 31, 2020 are as follows (in thousands):

Employee Stock Benefit Plans (T

Employee Stock Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2020
Table Text Blocks
Share-based compensation expense reflected in the condensed consolidated statements of operations	The following table summarizes share-based compensation expense (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2020 2019 Research and development ​ $ 1,396 ​ $ 2,918 ​ Selling, general and administrative ​ 4,968 ​ ​ 10,499 ​ Restructuring expenses ​ — ​ 517 ​ ​ ​ $ 6,364 ​ $ 13,934 ​ ​

Nature of Business - Notes Paya

Nature of Business - Notes Payable (Details) - USD ($) $ in Thousands	1 Months Ended
	Aug. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Aug. 12, 2019	Jun. 30, 2015
Convertible Senior Notes
Notes Payable
Net proceed received	$ 391,000
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued		$ 120,699	$ 120,699			$ 335,700
Stated interest rate (as a percent)	2.25%					2.25%
Fees and expenses						$ 11,700
Debt redeemed/repurchased	$ 215,000
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Fees and expenses	9,000
0.75% Convertible Senior Notes due 2024 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued	200,000	200,000	200,000		$ 200,000
Stated interest rate (as a percent)					0.75%
1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued	$ 200,000	$ 200,000	$ 200,000		$ 200,000
Stated interest rate (as a percent)					1.50%
8.375% Notes due 2026 | Notes Payable
Notes Payable
Stated interest rate (as a percent)				8.375%

Cyclerion Separation - Separati

Cyclerion Separation - Separation Agreement (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Apr. 01, 2019
Assets:
Prepaid expenses and other current assets	$ 10,443	$ 10,685
Property and equipment, net	12,164	12,429
Other assets	838	790
Total assets	404,005	402,748
Liabilities:
Accrued research and development costs	2,286	2,956
Accrued expenses and other current liabilities	$ 18,719	$ 30,465
Cyclerion Therapeutics, Inc.
Assets:
Prepaid expenses and other current assets			$ 1,169
Property and equipment, net			10,241
Other assets			21
Total assets			11,431
Liabilities:
Accrued research and development costs			5,673
Accrued expenses and other current liabilities			3,149
Total liabilities			8,822
Net Assets Transferred to Cyclerion			$ 2,609

Cyclerion Separation - General

Cyclerion Separation - General Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)agreement	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Cyclerion Separation
Transition services agreements | agreement	2
Initial term of service, low end of range	1 year
Initial term of service, high end of range	2 years
Research and Development Expense	$ 28,027	$ 32,198
Affiliated Entity
Cyclerion Separation
Tenant improvement reimbursement provisions			$ 1,300
Affiliated Entity | Research and development | Development Agreement [Member]
Cyclerion Separation
Research and Development Expense	$ 1,000

Cyclerion Separation - Summary

Cyclerion Separation - Summary of Expenses of Cyclerion (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2020
Net Loss from Discontinued Operations
Net loss from discontinued operations	$ 37,438
sGC Business | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Net Loss from Discontinued Operations
Net loss from discontinued operations	37,438
Liabilities		$ 0
Assets		$ 0
Research and development | sGC Business | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Net Loss from Discontinued Operations
Net loss from discontinued operations	21,792
Selling, general and administrative | sGC Business | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Net Loss from Discontinued Operations
Net loss from discontinued operations	$ 15,646

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	67,926	68,378
Employee stock options
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	15,647	24,080
Shares subject to repurchase
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	182	32
Time-vesting restricted stock units
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	4,945	3,641
Performance-based restricted stock units
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	543
Employee Stock Purchase Plan
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	105	125
Note Hedge Warrants
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	8,318	20,250
2.25% Convertible Senior Notes due 2022
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	8,318	20,250
0.75% Convertible Senior Notes due 2024
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	14,934
1.50% Convertible Senior Notes due 2026
Potentially dilutive securities
Total potentially dilutive securities excluded from the computation of diluted weighted average shares outstanding (in shares)	14,934

Collaboration, License, Co-Pr_3

Collaboration, License, Co-Promotion and Other Commercial Agreements - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenue	$ 79,943	$ 68,730
Collaborative arrangements revenue
Revenues:
Revenue	74,445	66,152
Collaborative arrangement, other agreements
Revenues:
Revenue	354	947
Sale of active pharmaceutical ingredient
Revenues:
Revenue	5,498	2,578
Allergan | North America | Collaborative arrangements revenue
Revenues:
Revenue	71,692	64,785
Allergan | North America | Collaborative arrangement, collaboration and license agreements
Revenues:
Revenue	71,692	64,785
Allergan | Europe and Other | Collaborative arrangement, collaboration and license agreements
Revenues:
Revenue	643	420
AstraZeneca | Sale of active pharmaceutical ingredient
Revenues:
Revenue		3
AstraZeneca | China, Hong Kong, and Macau | Collaborative arrangement, collaboration and license agreements
Revenues:
Revenue	332
AstraZeneca | China, Hong Kong, and Macau | Sale of active pharmaceutical ingredient
Revenues:
Revenue	5,498
Astellas Pharma Inc. | Japan | Collaborative arrangement, collaboration and license agreements
Revenues:
Revenue	479
Astellas Pharma Inc. | Japan | Sale of active pharmaceutical ingredient
Revenues:
Revenue		$ 2,575
Alnylam | Collaborative arrangement, co-promotion and other agreements
Revenues:
Revenue	$ 945

Collaboration, License, Co-Pr_4

Collaboration, License, Co-Promotion and Other Commercial Agreements - Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts receivable, net
Accounts receivable, net	$ 22,795	$ 32,597
Accounts payable due related party	1,058	1,509
Collaborative arrangements and active pharmaceutical ingredient
Accounts receivable, net
Accounts receivable, net	40,500	43,900
Accounts receivable, net and related party accounts receivable, net, net of related party accounts payable	73,400	110,100
Accounts payable due related party	4,600	$ 4,100
Deferred revenue	$ 900

Collaboration, License, Co-Pr_5

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - General Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)itempayment	Mar. 31, 2019USD ($)
Collaboration, License and Co-Promotion Agreements
Research and development expense	$ 28,027	$ 32,198
Sales milestones
Collaboration, License and Co-Promotion Agreements
Sales-related milestone if certain conditions are met	100,000
Allergan
Collaboration, License and Co-Promotion Agreements
Equity investment in the entity's capital stock	25,000
Research and development expense	6,600	10,000
Net cost sharing offset or incremental expense related to research and development expense	$ 800	$ 3,200
Remaining commercial-period performance obligations | item	3
Allergan | Development and sales milestones
Collaboration, License and Co-Promotion Agreements
Cumulative license fees and development milestone payments received	$ 205,000
Allergan | Development milestones
Collaboration, License and Co-Promotion Agreements
Number of milestone payments received | payment	6
Allergan | Sales milestones
Collaboration, License and Co-Promotion Agreements
Percentage of net profit from commercialization (as a percent)	50.00%
Percentage of net loss from commercialization (as a percent)	50.00%

Collaboration, License, Co-Pr_6

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Collaborative Arrangements Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenue	$ 79,943	$ 68,730
Collaborative arrangements revenue
Revenues:
Revenue	74,445	66,152
Allergan | North America | Collaborative arrangements revenue
Revenues:
Revenue	71,692	64,785
Allergan | North America | Collaborative arrangements, LINZESS
Revenues:
Revenue	71,142	64,293
Allergan | North America | Royalty
Revenues:
Revenue	$ 550	$ 492

Collaboration, License, Co-Pr_7

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Commercial Efforts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Collaboration, License and Co-Promotion Agreements
Revenue	$ 79,943	$ 68,730
Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Revenue	74,445	66,152
Collaborative arrangements, LINZESS | Allergan
Collaboration, License and Co-Promotion Agreements
Patent and litigation costs	200	500
Collaborative arrangements, LINZESS | Allergan | U.S.
Collaboration, License and Co-Promotion Agreements
Revenue	71,142	64,293
Selling, general and administrative costs incurred by the Company	(8,674)	(10,277)
The Company's share of net profit	$ 62,468	$ 54,016

Collaboration, License, Co-Pr_8

Collaboration, License, Co-Promotion and Other Commercial Agreements - North America - Royalty Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenue	$ 79,943	$ 68,730
Collaborative arrangements revenue
Revenues:
Revenue	74,445	66,152
Collaborative arrangements revenue | North America | Allergan
Revenues:
Revenue	71,692	64,785
Royalty | North America | Allergan
Revenues:
Revenue	550	492
Royalty | Canada and Mexico | Allergan
Revenues:
Revenue	$ 600	$ 500

Collaboration, License, Co-Pr_9

Collaboration, License, Co-Promotion and Other Commercial Agreements - European and Other Territories (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Oct. 31, 2015	Sep. 30, 2012
Collaboration, License and Co-Promotion Agreements
Revenue	$ 79,943	$ 68,730
Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Revenue	$ 74,445	66,152
License | Allergan
Collaboration, License and Co-Promotion Agreements
Royalty percentage, five years following the first commercial sale	upper-single digits
Annual royalty	5 years
Royalty percentage, thereafter	low-double digits
Royalty percentage, expanded territory	lower-single digits
License | Allergan | Europe
Collaboration, License and Co-Promotion Agreements
Remaining milestone payment due upon the amendment to the license agreement			$ 42,500
Revenue remaining performance obligation				$ 0
Royalty | Allergan | Europe
Collaboration, License and Co-Promotion Agreements
Revenue	$ 600	$ 400

Collaboration, License, Co-P_10

Collaboration, License, Co-Promotion and Other Commercial Agreements - Japan (Details) $ in Thousands	Aug. 01, 2019USD ($)	Nov. 30, 2009USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)payment	Dec. 31, 2016USD ($)
Collaboration, License and Co-Promotion Agreements
Revenue			$ 79,943	$ 68,730
Astellas Pharma Inc. | Japan
Collaboration, License and Co-Promotion Agreements
Up-front fee received		$ 30,000
Astellas Pharma Inc. | Japan | Additional development milestones
Collaboration, License and Co-Promotion Agreements
Number of milestone payments | payment					3
Total milestone payments to be received					$ 45,000
Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Revenue			74,445	66,152
Collaborative arrangement, collaboration and license agreements | Astellas Pharma Inc. | Japan
Collaboration, License and Co-Promotion Agreements
Revenue			479
Revenue remaining performance obligation	$ 20,400
Non-refundable upfront payment	$ 10,000
Sale of active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue			5,498	2,578
Sale of active pharmaceutical ingredient | Astellas Pharma Inc. | Japan
Collaboration, License and Co-Promotion Agreements
Revenue				2,575
Revenue remaining performance obligation						$ 0
Sale of active pharmaceutical ingredient | Astellas Pharma Inc., 2009 License Agreement | Japan
Collaboration, License and Co-Promotion Agreements
Revenue				$ 2,600
Royalty | Astellas Pharma Inc. | Japan
Collaboration, License and Co-Promotion Agreements
Revenue			$ 400

Collaboration, License, Co-P_11

Collaboration, License, Co-Promotion and Other Commercial Agreements - China, Hong Kong and Macau (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Sep. 30, 2019USD ($)installment	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)
Collaboration, License and Co-Promotion Agreements
Revenue		$ 79,943	$ 68,730
Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Revenue		74,445	66,152
Sale of active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue		5,498	2,578
AstraZeneca | Sale of active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue			3
AstraZeneca | China, Hong Kong, and Macau | Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Collaborative arrangement, significant financing component, transaction price	$ 2,600
Collaborative arrangement, expected interest income		2,600
AstraZeneca | China, Hong Kong, and Macau | Collaborative arrangement, collaboration and license agreements
Collaboration, License and Co-Promotion Agreements
Revenue		332
AstraZeneca | China, Hong Kong, and Macau | Collaborative arrangement, collaboration agreements
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement	90,000
Pre-launch commercial services and supply chain services			$ 200
Amount of non-contingent arrangement consideration	$ 35,000
Non-contingent consideration installments | installment	3
Percentage of tiered royalties	20.00%
Revenue		32,400
Interest income		200
AstraZeneca | China, Hong Kong, and Macau | Collaborative arrangement, transition services agreement
Collaboration, License and Co-Promotion Agreements
Regulatory and administrative services initial term	2 years
AstraZeneca | China, Hong Kong, and Macau | Sale of active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Revenue		$ 5,498
AstraZeneca | China, Hong Kong, and Macau | Commercialization milestone | Collaborative arrangement, collaboration agreements
Collaboration, License and Co-Promotion Agreements
Percentage of net loss from commercialization (as a percent)		55.00%
AstraZeneca Service Agreement | China, Hong Kong, and Macau | Collaborative arrangement, collaboration agreements
Collaboration, License and Co-Promotion Agreements
Revenue		$ 200

Collaboration, License, Co-P_12

Collaboration, License, Co-Promotion and Other Commercial Agreements - Co-Promotion Agreements (Details) - USD ($) $ in Thousands	Aug. 09, 2019	Mar. 31, 2020	Mar. 31, 2019
Collaboration, License and Co-Promotion Agreements
Revenue		$ 79,943	$ 68,730
Collaborative arrangements and active pharmaceutical ingredient
Collaboration, License and Co-Promotion Agreements
Deferred revenue		900
Collaborative arrangements revenue
Collaboration, License and Co-Promotion Agreements
Revenue		74,445	$ 66,152
Alnylam | Collaborative arrangement, co-promotion and other agreements
Collaboration, License and Co-Promotion Agreements
Revenue		945
Alnylam | Collaborative arrangement, promotion agreements
Collaboration, License and Co-Promotion Agreements
Total annual service fees due	$ 9,500
Term of agreement	3 years
Revenue		900
Deferred revenue		900
Alnylam | Service fees
Collaboration, License and Co-Promotion Agreements
Revenue		$ 900

Collaboration, License, Co-P_13

Collaboration, License, Co-Promotion and Other Commercial Agreements - Other Collaborations and License Agreements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Collaboration, License and Co-Promotion Agreements
Research and development	$ 28,027	$ 32,198
Collaborative arrangement, co-promotion and other agreements | Development and sales milestones
Collaboration, License and Co-Promotion Agreements
Maximum payment receivable under the milestone	63,500
Collaborative arrangement, other agreements
Collaboration, License and Co-Promotion Agreements
Revenue related to nonrefundable upfront payments		500
Research and development	0	$ 0
Collaborative arrangement, other agreements | Regulatory milestones
Collaboration, License and Co-Promotion Agreements
Contingent milestone payable	18,000
Milestone payment made	$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - General Information (Details)	Mar. 31, 2020
Fair Value of Financial Instruments
Threshold percentage of collateralized value (as a percent)	102.00%

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Measured on Recurring Basis (Details) - Recurring basis - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Convertible note hedges	$ 15,847	$ 31,366
Total assets measured at fair value	233,858	210,577
Liabilities:
Note hedge warrants	12,207	24,260
Total liabilities measured at fair value	12,207	24,260
Money market funds
Assets:
Cash and cash equivalents	215,790	139,190
Restricted cash	2,221	2,221
Repurchase agreements
Assets:
Cash and cash equivalents		37,800
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total assets measured at fair value	218,011	179,211
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Assets:
Cash and cash equivalents	215,790	139,190
Restricted cash	2,221	2,221
Quoted Prices in Active Markets for Identical Assets (Level 1) | Repurchase agreements
Assets:
Cash and cash equivalents		37,800
Significant Unobservable Inputs (Level 3)
Assets:
Convertible note hedges	15,847	31,366
Total assets measured at fair value	15,847	31,366
Liabilities:
Note hedge warrants	12,207	24,260
Total liabilities measured at fair value	$ 12,207	$ 24,260

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Transfers Between Fair Value Measurement Levels (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair value transfers
Fair value transfer between measurement levels	$ 0	$ 0

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Assumptions - Convertible Note Hedges (Details)	Mar. 31, 2020$ / sharesY	Dec. 31, 2019$ / sharesY
Fair Value of Financial Instruments
Derivative asset, valuation technique	us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Risk Free Interest Rate
Fair Value of Financial Instruments
Derivative asset, measurement input	0.002	0.016
Measurement Input, Expected Term
Fair Value of Financial Instruments
Derivative asset, measurement input | Y	2.2	2.5
Measurement Input, Share Price
Fair Value of Financial Instruments
Derivative asset, measurement input	10.09	13.31
Measurement Input, Exercise Price
Fair Value of Financial Instruments
Derivative asset, measurement input	14.51	14.51
Measurement Input, Price Volatility
Fair Value of Financial Instruments
Derivative asset, measurement input	0.524	0.491
Measurement Input, Expected Dividend Rate
Fair Value of Financial Instruments
Derivative asset, measurement input	0	0

Fair Value of Financial Instr_7

Fair Value of Financial Instruments - Assumptions - Note Hedge Warrants (Details)	Mar. 31, 2020Y$ / shares	Dec. 31, 2019Y$ / shares
Fair Value of Financial Instruments
Derivative asset, valuation technique	us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Derivative liability, valuation technique	us-gaap:ValuationTechniqueOptionPricingModelMember	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Risk Free Interest Rate
Fair Value of Financial Instruments
Derivative liability, measurement input	0.003	0.016
Measurement Input, Expected Term
Fair Value of Financial Instruments
Derivative liability, measurement input | Y	2.8	3
Measurement Input, Share Price
Fair Value of Financial Instruments
Derivative liability, measurement input	10.09	13.31
Measurement Input, Exercise Price
Fair Value of Financial Instruments
Derivative liability, measurement input	18.82	18.82
Measurement Input, Price Volatility
Fair Value of Financial Instruments
Derivative liability, measurement input	0.501	0.465
Measurement Input, Expected Dividend Rate
Fair Value of Financial Instruments
Derivative liability, measurement input	0	0

Fair Value of Financial Instr_8

Fair Value of Financial Instruments - Change in Level 3 - Convertible Note Hedges (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Change in Level 3 Assets
Balance at beginning of period	$ 31,366
Change in fair value, recorded as a component of (loss) gain on derivatives	(15,519)
Balance at end of period	$ 15,847

Fair Value of Financial Instr_9

Fair Value of Financial Instruments - Change in Level 3 - Note Hedge Warrants (Details) - Warrants $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Change in Level 3 Liabilities
Balance at beginning of period	$ (24,260)
Change in fair value, recorded as a component of (loss) gain on derivatives	12,053
Balance at end of period	$ (12,207)

Fair Value of Financial Inst_10

Fair Value of Financial Instruments - Notes Payable (Details) - Convertible Senior Notes - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Aug. 31, 2019	Aug. 12, 2019	Jun. 30, 2015
2.25% Convertible Senior Notes due 2022
Fair value disclosures
Debt Instrument, Repurchased Face Amount			$ 215,000
Aggregate principal amount of notes issued	$ 120,699	$ 120,699			$ 335,700
2.25% Convertible Senior Notes due 2022 | Significant Other Observable Inputs (Level 2)
Fair value disclosures
Estimated fair value	124,700	141,300
0.75% Convertible Senior Notes due 2024
Fair value disclosures
Aggregate principal amount of notes issued	200,000	200,000	200,000	$ 200,000
0.75% Convertible Senior Notes due 2024 | Significant Other Observable Inputs (Level 2)
Fair value disclosures
Estimated fair value	202,100	235,700
1.50% Convertible Senior Notes due 2026
Fair value disclosures
Aggregate principal amount of notes issued	200,000	200,000	$ 200,000	$ 200,000
1.50% Convertible Senior Notes due 2026 | Significant Other Observable Inputs (Level 2)
Fair value disclosures
Estimated fair value	$ 202,400	$ 240,100

Fair Value of Financial Inst_11

Fair Value of Financial Instruments - Capped Calls in connection with issuance of 2024 Convertible Notes and the 2026 Convertible Notes (Details) - Capped Calls with Respect to 2024 Convertible Notes and 2026 Convertible Notes	1 Months Ended
	Aug. 31, 2019$ / shares$ / itemshares	Mar. 31, 2020$ / item
Capped Calls
Number of shares covered by capped calls (in shares) | shares	29,867,480
Strike price (in dollars per share) | $ / shares	$ 13.39
Cap price | $ / item	17.05	17.05

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Expenses
Salaries	$ 1,582	$ 2,973
Accrued vacation	3,007	2,540
Accrued incentive compensation	3,672	11,760
Other employee benefits	2,084	1,260
Professional fees	2,036	1,421
Accrued interest	2,105	301
Other	4,233	10,210
Total accrued expenses and other current liabilities	$ 18,719	$ 30,465

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Expenses
Other accrued expenses	$ 4,233	$ 10,210
Unbilled inventories	900	600
Equipment for clinical studies	300
Franchise Taxes	200
Facility services	200
Public relations services	$ 200
Other accrued expenses contracted services		200
Accrued Expenses and Other Current Liabilities
Accrued Expenses
Move activities		900
Accrued non-cancelable purchase		$ 4,100

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lease cost
Operating lease cost during period	$ 633	$ 4,525
Short-term lease cost	372	389
Total lease cost	$ 1,005	$ 4,914

Leases - Operating Leases - Sup

Leases - Operating Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating leases
Right-of-use assets obtained in exchange for new operating lease upon adoption of ASC 842		$ 88,299
Cash paid for amounts included in the measurement of lease liabilities	$ 43	$ 4,412
Weighted-average remaining lease term of operating leases (in years)	10 years	5 years 8 months 12 days
Weighted-average discount rate of operating leases (as a percent)	5.80%	6.70%

Leases - Operating Leases - Fut

Leases - Operating Leases - Future Minimum Lease Payments - ASC 842 (Details) $ in Thousands	Mar. 31, 2020USD ($)
Future minimum lease payments
2020	$ 1,102
2021	3,128
2022	3,129
2023	3,065
2024	3,126
2025 and thereafter	18,044
Total future minimum lease payments	$ 31,594

Leases - Operating Leases - Ope

Leases - Operating Leases - Operating Lease Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating lease obligations
Total future minimum lease payments	$ 31,594
Less: amounts representing imputed interest	(8,072)
Operating lease liabilities	23,522
Less: current portion of operating lease obligations	1,876	$ 1,146
Operating lease obligations, net of current portion	$ 21,646	$ 22,082

Leases - Operating Leases - Sum

Leases - Operating Leases - Summer Street Lease (Details) $ in Thousands	Jun. 11, 2019	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Nov. 11, 2019ft²
Operating leases
Restricted cash, noncurrent		$ 971		$ 971
Weighted-average discount rate of operating leases (as a percent)		5.80%	6.70%
Operating lease right-of-use assets		$ 17,447		17,743
Operating lease liability		23,522
Operating lease cost		633	$ 4,525
Summer Street Lease
Operating leases
Option to extend the term of the lease	true
Rentable area leased (in square feet) | ft²					39,000
Operating lease, renewal term	5 years
Annual rent escalation (as a percent)	2.00%
Restricted cash, noncurrent		$ 1,000
Weighted-average discount rate of operating leases (as a percent)		5.80%
Operating lease right-of-use assets		$ 17,400		17,700
Operating lease liability		23,100		$ 22,800
Operating lease cost		$ 600

Leases - Operating Leases - Bin

Leases - Operating Leases - Binney Street Lease (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating leases
Operating lease cost	$ 633	$ 4,525
Binney Street Lease
Operating leases
Operating lease cost		$ 2,600

Leases - Operating Leases - Dat

Leases - Operating Leases - Data Center Colocation Lease (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating leases
Operating lease right-of-use assets		$ 17,447	$ 17,743
Operating lease liability		$ 23,522
Asset impairment charge
Weighted-average discount rate of operating leases (as a percent)	6.70%	5.80%
Data Center Lease, Boston, Massachusetts
Operating leases
Annual rent escalation (as a percent)		4.00%
Operating lease right-of-use assets				$ 600
Operating lease liability		$ 400	$ 400	$ 600
Asset impairment charge
Weighted-average discount rate of operating leases (as a percent)		6.00%
Data Center Lease, Boston, Massachusetts | Selling, general and administrative
Asset impairment charge
Asset impairment charge	$ 500

Leases - Operating Leases - Veh

Leases - Operating Leases - Vehicle Fleet Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Apr. 30, 2018
Operating leases
Restricted cash, noncurrent	$ 971		$ 971
Operating lease cost	633	$ 4,525
Vehicles, 2018 Vehicle Leases
Operating leases
Operating lease, term				12 months
Operating lease, renewal term				1 month
Restricted cash, noncurrent	1,300		$ 1,300
Operating lease cost	$ 400	$ 400

Notes Payable - 8.375% Notes Du

Notes Payable - 8.375% Notes Due 2026 (Details) - USD ($) $ in Thousands	1 Months Ended
	Aug. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2015
Notes Payable
Proceeds from partial termination of convertible note hedges and note hedge warrants	$ 3,200
8.375% Notes due 2026 | Notes Payable
Notes Payable
Stated interest rate (as a percent)				8.375%
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued		$ 120,699	$ 120,699		$ 335,700
Stated interest rate (as a percent)	2.25%				2.25%
Debt redeemed/repurchased	$ 215,000
Debt redemption/repurchase price	227,300
Loss on extinguishment of debt	23,400
Initial debt issuance costs	2,800
Equity component of convertible senior notes	$ (27,000)

Notes Payable - 2.25% Convertib

Notes Payable - 2.25% Convertible Senior Notes Due 2022 - General Information (Details)	Apr. 15, 2019USD ($)$ / sharesshares	Aug. 31, 2019USD ($)	Jun. 30, 2015USD ($)D$ / sharesshares	Mar. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)
Notes Payable
Payments for convertible note hedges		$ 25,200,000	$ 21,100,000
Note Hedge Warrants
Notes Payable
Warrants strike price (in dollars per share) | $ / shares	$ 18.82			$ 21.50
Convertible Note Hedge
Notes Payable
Conversion price (in dollars per share) | $ / shares	$ 14.51			$ 16.58
Shares issuable upon conversion of debt (in shares) | shares				20,249,665
2.25% Convertible Senior Notes due 2022 | Note Hedge Warrants
Notes Payable
Shares issuable upon conversion of debt (in shares) | shares	23,135,435
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued			335,700,000	$ 120,699,000	$ 120,699,000
Net proceed received			324,000,000
Fees and expenses			$ 11,700,000
Stated interest rate (as a percent)		2.25%	2.25%
Conversion rate, number of shares to be issued per	68.9172		60.3209
Principal amount used for debt instrument conversion ratio	$ 1,000		$ 1,000
Conversion price (in dollars per share) | $ / shares	$ 14.51		$ 16.58
Shares issuable upon conversion of debt (in shares) | shares	23,135,435		20,249,665
Number of trading days | D			20
Consecutive trading days | D			30
Minimum percentage of stock price			130.00%
Number of business days immediately after any five consecutive trading day period during the measurement period | D			5
Number of consecutive trading days before five business days during the measurement period | D			5
Repurchase price, as percentage of principal amount, if company undergoes change of control			100.00%
Maximum period of the sole remedy for event failures in the Indenture				180 days
Amortization period			7 years
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes | Minimum
Notes Payable
Percentage of aggregate principal amount payable, in case of event of default			25.00%
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes | Maximum
Notes Payable
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate			98.00%

Notes Payable - 2.25% Convert_2

Notes Payable - 2.25% Convertible Senior Notes Due 2022 - Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Aug. 31, 2019	Aug. 12, 2019	Jun. 30, 2015
Liability component:
Long-term Debt, Gross	$ 553,738
Less: unamortized debt discount	(99,631)
Less: unamortized debt issuance costs	(7,659)
Net carrying amount	413,409
Convertible Senior Notes
Liability component:
Less: unamortized debt discount	(99,631)	$ (104,700)
Less: unamortized debt issuance costs	(7,659)	(8,005)
Net carrying amount	413,409	407,994
Total equity component	112,309	112,309
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued	120,699	120,699			$ 335,700
Total equity component	19,807	19,807
0.75% Convertible Senior Notes due 2024 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued	200,000	200,000	$ 200,000	$ 200,000
Total equity component	41,152	41,152
1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued	200,000	200,000	$ 200,000	$ 200,000
Total equity component	$ 51,350	$ 51,350

Notes Payable - 2.25% Convert_3

Notes Payable - 2.25% Convertible Senior Notes Due 2022 - Additional Information (Details) - 2.25% Convertible Senior Notes due 2022 - Convertible Senior Notes - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2015	Mar. 31, 2020
Notes Payable
Debt issuance costs incurred	$ 11.7
Debt issuance costs allocated to equity components	4
Debt issuance costs allocated to liability components	$ 7.7
Debt instrument term	7 years
Effective interest rate on liability components		9.50%

Notes Payable - 2.25% Convert_4

Notes Payable - 2.25% Convertible Senior Notes Due 2022 - Total Interest Expense (Details) - 2.25% Convertible Senior Notes due 2022 - Convertible Senior Notes - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest Expense
Contractual interest expense	$ 1,805	$ 1,888
Amortization of debt issuance costs	346	272
Amortization of debt discount	5,069	4,075
Total interest expense	$ 7,220	$ 6,235

Notes Payable - 2.25% Convert_5

Notes Payable - 2.25% Convertible Senior Notes Due 2022 - Future Minimum Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Future minimum payments of Convertible senior notes
2020	$ 7,216
2021	7,216
2022	126,556
2023	4,500
2024	203,750
2025	3,000
2026 and Thereafter	201,500
Total future minimum payments under the convertible senior notes	553,738
Less: amounts representing interest	(33,039)
Less: unamortized debt discount	(99,631)
Less: unamortized debt issuance costs	(7,659)
Net carrying amount	413,409
Convertible Senior Notes
Future minimum payments of Convertible senior notes
Less: unamortized debt discount	(99,631)	$ (104,700)
Less: unamortized debt issuance costs	(7,659)	(8,005)
Net carrying amount	$ 413,409	$ 407,994

Notes Payable - 0.75% Convertib

Notes Payable - 0.75% Convertible Senior Notes Due 2024 and 1.50% Convertible Senior Notes Due 2026 (Details)	Aug. 12, 2019USD ($)	Aug. 07, 2019USD ($)$ / shares	Apr. 15, 2019USD ($)$ / sharesshares	Aug. 31, 2019USD ($)D	Jun. 30, 2015USD ($)D$ / sharesshares	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Notes Payable
Payments for convertible note hedges				$ 25,200,000	$ 21,100,000
Repurchase price				100.00%
The percentage of aggregate principal amount of notes outstanding and payable in case of event of default under the agreement.				25.00%
Default payment days						180 days
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued					335,700,000	$ 120,699,000	$ 120,699,000
Net proceed received					324,000,000
Fees and expenses					$ 11,700,000
Stated interest rate (as a percent)				2.25%	2.25%
Conversion rate, number of shares to be issued per			68.9172		60.3209
Principal amount used for debt instrument conversion ratio			$ 1,000		$ 1,000
Initial conversion price (in dollars per share) | $ / shares			$ 14.51		$ 16.58
Shares issuable upon conversion of debt (in shares) | shares			23,135,435		20,249,665
Number of trading days | D					20
Consecutive trading days | D					30
Minimum percentage of stock price					130.00%
Number of business days immediately after any five consecutive trading day period during the measurement period | D					5
Number of consecutive trading days before five business days during the measurement period | D					5
Repurchase price, as percentage of principal amount, if company undergoes change of control					100.00%
Amortization period					7 years
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes | Minimum
Notes Payable
Percentage of aggregate principal amount payable, in case of event of default					25.00%
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes | Maximum
Notes Payable
Percentage of the trading price to the product of the sale price of the entity's common stock and the conversion rate					98.00%
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Net proceed received				$ 391,000,000
Fees and expenses				9,000,000
Conversion rate, number of shares to be issued per	74.6687
Principal amount used for debt instrument conversion ratio		$ 1,000		$ 1,000
Initial conversion price (in dollars per share) | $ / shares		$ 13.39
Conversion premium percentage on sale price of common stock		37.50%
Share Price | $ / shares		$ 9.74
Number of consecutive trading days before five business days during the measurement period | D				5
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes | Calendar quarter commencing after December 31, 2019
Notes Payable
Number of trading days | D				20
Consecutive trading days | D				30
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes | Measurement period
Notes Payable
Number of business days immediately after any five consecutive trading day period during the measurement period | D				5
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes | Minimum | Calendar quarter commencing after December 31, 2019
Notes Payable
Minimum percentage of stock price				130.00%
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes | Maximum | Measurement period
Notes Payable
Conversion premium percentage on sale price of common stock				98.00%
0.75% Convertible Senior Notes due 2024 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued	$ 200,000,000			$ 200,000,000		200,000,000	200,000,000
Stated interest rate (as a percent)	0.75%
Amortization period				5 years
1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Aggregate principal amount of notes issued	$ 200,000,000			$ 200,000,000		$ 200,000,000	$ 200,000,000
Stated interest rate (as a percent)	1.50%
Amortization period				7 years

Notes Payable - 2.25% Convert_6

Notes Payable - 2.25% Convertible Senior Notes Due 2022, 0.75% Convertible Senior Notes Due 2024 and 1.50% Convertible Senior Notes Due 2026 (Details) - Convertible Senior Notes - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2019	Jun. 30, 2015	Mar. 31, 2020
2.25% Convertible Senior Notes due 2022
Debt Instruments [Abstract]
Debt issuance costs incurred		$ 11.7
Debt issuance costs allocated to equity components		4
Debt issuance costs allocated to liability components		$ 7.7
Debt instrument term		7 years
Effective interest rate on liability components			9.50%
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026
Debt Instruments [Abstract]
Debt issuance costs incurred	$ 9
Debt issuance costs allocated to equity components	2.1
Debt issuance costs allocated to liability components	$ 6.9
0.75% Convertible Senior Notes due 2024
Debt Instruments [Abstract]
Debt instrument term	5 years
Effective interest rate on liability components			6.10%
1.50% Convertible Senior Notes due 2026
Debt Instruments [Abstract]
Debt instrument term	7 years
Effective interest rate on liability components			6.50%

Notes Payable - Convertible Not

Notes Payable - Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 15, 2019	Jun. 30, 2015	Mar. 31, 2020	Dec. 31, 2019
Notes Payable
Long-term asset			$ 15,847	$ 31,366
Long-term liability			$ 12,207	$ 24,260
Net derivative issuance cost		$ 21,100
Convertible Note Hedge
Notes Payable
Shares issuable upon conversion of debt (in shares)			20,249,665
Conversion price (in dollars per share)	$ 14.51		$ 16.58
Long-term asset		91,900
Note Hedge Warrant Derivatives
Notes Payable
Shares into which warrants may be converted (in shares)			20,249,665
Trading day period			150 days
Long-term liability		$ 70,800
Note Hedge Warrants
Notes Payable
Warrants strike price (in dollars per share)	$ 18.82		$ 21.50
Note Hedge Warrants | 2.25% Convertible Senior Notes due 2022
Notes Payable
Shares issuable upon conversion of debt (in shares)	23,135,435

Notes Payable - Capped Calls wi

Notes Payable - Capped Calls with Respect to 2024 Convertible Notes and 2026 Convertible Notes (Details) - Capped Calls with Respect to 2024 Convertible Notes and 2026 Convertible Notes $ / shares in Units, $ in Millions	1 Months Ended
	Aug. 31, 2019USD ($)$ / shares$ / itemshares	Mar. 31, 2020$ / item
Capped Calls
Payment made to enter into Capped Calls	$ 25.2
Strike price (in dollars per share) | $ / shares	$ 13.39
Cap price | $ / item	17.05	17.05
Percentage of cap premium (as a percent)	75.00%
Number of shares covered by capped calls (in shares) | shares	29,867,480
Purchase of capped calls	$ 25
Equity component of issuance costs for convertible senior notes	$ 0.2

Employee Stock Benefit Plans -

Employee Stock Benefit Plans - Share-based Compensation Reflected in the Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Employee Stock Benefit Plans
Share-based compensation expense	$ 6,364	$ 13,934
Research and development
Employee Stock Benefit Plans
Share-based compensation expense	1,396	2,918
Selling, general and administrative
Employee Stock Benefit Plans
Share-based compensation expense	$ 4,968	10,499
Restructuring expenses
Employee Stock Benefit Plans
Share-based compensation expense		$ 517

Employee Stock Benefit Plans _2

Employee Stock Benefit Plans - Workforce Reduction (Details) $ in Thousands	Feb. 07, 2019employee	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)
Employee Stock Benefit Plans
Share-based compensation expense		$ 6,364	$ 13,934
Reduction in Workforce, February 7, 2019
Workforce Reduction
Number of employees expected to be eliminated | employee	35
Employee Stock Benefit Plans
Share-based compensation expense			$ 500

Employee Stock Benefit Plans _3

Employee Stock Benefit Plans - Share-based Compensation Expense (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Employee Stock Benefit Plans
Share-based compensation expense, other modifications	$ 2.4

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Related Party Transactions
Accounts payable due related party	$ 1,058		$ 1,509
Investor | Allergan
Related Party Transactions
Accounts receivable	73,400		106,000
Board of Directors member
Related Party Transactions
Amount of insurance premium paid to the insurance provider	2,400	$ 2,500
Related party prepaid assets	600
Accounts payable due to related party	0		0
Board of Directors member | Cyclerion Therapeutics, Inc.
Related Party Transactions
Accounts payable due related party	$ 1,100		$ 1,500

Workforce Reduction - General I

Workforce Reduction - General Information (Details) $ in Thousands	Feb. 07, 2019employee	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)
Restructuring expenses
Restructuring expenses		$ 0	$ 3,328
Restructuring accruals		$ 200		$ 200
Reduction in Workforce, February 7, 2019
Workforce Reduction
Number of employees expected to be eliminated | employee	35
Restructuring expenses
Employee severance, benefits and related costs			$ 3,300