Intercept Pharmaceuticals (ICPT) 10-K 1 Mar 17 2016 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 31, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	INTERCEPT PHARMACEUTICALS INC
Entity Central Index Key	1,270,073
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	icpt
Entity Common Stock, Shares Outstanding		24,831,471
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,016
Entity Well-Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,520,761,550

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 43,675	$ 32,742
Investment securities, available-for-sale	645,710	595,313
Accounts receivable	9,126
Prepaid expenses and other current assets	9,354	13,638
Total current assets	707,865	641,693
Fixed assets, net	11,295	10,047
Inventory	2,279
Security deposits	17,814	4,018
Total assets	739,253	655,758
Current liabilities:
Accounts payable, accrued expenses and other liabilities	65,551	45,591
Short-term interest payable	7,267
Short-term portion of deferred revenue	5,694	1,782
Total current liabilities	78,512	47,373
Long-term liabilities:
Long-term debt	341,356
Long-term portion of deferred revenue	4,453	6,236
Total liabilities	424,321	53,609
Stockholders' equity:
Common stock par value $0.001 per share; 45,000,000 and 35,000,000 shares authorized; 24,819,918 and 24,391,430 shares issued and outstanding as of December 31, 2016 and December 31, 2015, respectively	25	24
Additional paid-in capital	1,426,168	1,300,008
Accumulated other comprehensive loss, net	(2,801)	(2,253)
Accumulated deficit	(1,108,460)	(695,630)
Total stockholders' equity	314,932	602,149
Total liabilities and stockholders' equity	$ 739,253	$ 655,758

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized	45,000,000	35,000,000
Common stock, issued	24,819,918	24,391,430
Common stock, outstanding	24,819,918	24,391,430

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Product revenue, net	$ 18,169
Licensing revenue	6,782	$ 2,782	$ 1,742
Total revenue	24,951	2,782	1,742
Operating expenses:
Selling, general and administrative	273,596	119,242	34,601
Research and development	153,893	112,696	80,311
Total operating expenses	427,489	231,938	114,912
Operating loss	(402,538)	(229,156)	(113,170)
Other income (expense):
Revaluation of warrants			(170,832)
Interest expense	(14,196)
Other income, net	3,904	2,727	776
Total other income (expense)	(10,292)	2,727	(170,056)
Net loss	$ (412,830)	$ (226,429)	$ (283,226)
Net Loss Per Share [Abstract]
Net loss per share, basic and diluted (in dollars per share)	$ (16.74)	$ (9.56)	$ (13.63)
Weighted average shares outstanding, basic and diluted	24,663	23,694	20,784

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Comprehensive Loss:
Net loss	$ (412,830)	$ (226,429)	$ (283,226)
Other comprehensive (loss):
Unrealized holding gains (losses) arising during the period	378	(1,628)	(369)
Reclassification for recognized gains (losses) on marketable investment securities during the period recognized in other income, net	(48)	3	25
Net unrealized gains (losses) on marketable investment securities	330	(1,625)	(344)
Foreign currency translation adjustments	(878)	(347)
Total comprehensive loss	$ (413,378)	$ (228,401)	$ (283,570)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2013	$ 19	$ 268,303	$ (185,975)	$ 60	$ 82,407
Balance (in shares) at Dec. 31, 2013	19,390
Stock-based compensation		20,127			20,127
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs	$ 1	183,475			183,476
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs (in shares)	600
Warrants converted to common stock	$ 1	220,943			220,944
Warrants converted to common stock (in shares)	835
Net proceeds from exercise of stock options	$ 1	7,507			7,508
Net proceeds from exercise of stock options (in shares)	591
Other comprehensive income (loss)				(341)	(341)
Net loss			(283,226)		(283,226)
Balance at Dec. 31, 2014	$ 22	700,355	(469,201)	(281)	230,895
Balance (in shares) at Dec. 31, 2014	21,416
Stock-based compensation		34,189			34,189
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs	$ 1	558,753			558,754
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs (in shares)	2,481
Net proceeds from exercise of stock options	$ 1	6,711			6,712
Net proceeds from exercise of stock options (in shares)	495
Other comprehensive income (loss)				(1,972)	(1,972)
Net loss			(226,429)		(226,429)
Balance at Dec. 31, 2015	$ 24	1,300,008	(695,630)	(2,253)	602,149
Balance (in shares) at Dec. 31, 2015	24,392
Stock-based compensation		46,205			46,205
Recognition of debt discount on convertible notes		113,145			113,145
Purchase of capped call transactions and associated costs		(38,364)			(38,364)
Net proceeds from exercise of stock options	$ 1	5,174			$ 5,175
Net proceeds from exercise of stock options (in shares)	428				185
Other comprehensive income (loss)				(548)	$ (548)
Net loss			(412,830)		(412,830)
Balance at Dec. 31, 2016	$ 25	$ 1,426,168	$ (1,108,460)	$ (2,801)	$ 314,932
Balance (in shares) at Dec. 31, 2016	24,820

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (412,830)	$ (226,429)	$ (283,226)
Adjustments to reconcile net loss to net cash used in operating activities:
Revaluation of warrants			170,832
Share-based compensation	46,205	34,189	20,127
Amortization of investment premium	4,939	6,302	3,366
Amortization of deferred financing costs	685
Realized loss on investments	48
Depreciation	3,831	1,691	443
Loss on the disposal of property and equipment			20
Accretion of debt discount	6,242
Changes in:
Prepaid expenses and other current assets	4,284	(7,516)	(3,371)
Security deposits	(13,796)	(1,575)	(1,388)
Accounts receivable	(9,126)
Inventory	(2,279)
Accounts payable, accrued expenses, and other current liabilities	19,960	32,218	6,200
Interest payable	7,267
Deferred revenue	2,129	(1,782)	(741)
Net cash used in operating activities	(342,441)	(162,902)	(87,738)
Cash flows from investing activities:
Purchases of investment securities	(511,521)	(640,709)	(204,344)
Sales of investment securities	456,465	257,172	112,402
Purchases of equipment, leasehold improvements, and furniture and fixtures	(5,079)	(5,935)	(4,643)
Net cash used in investing activities	(60,135)	(389,472)	(96,585)
Cash flows from financing activities:
Proceeds from issuance of stock offerings, net of issuance costs		558,756	183,475
Payments for capped call transactions and associated costs	(38,364)
Proceeds from issuance of Convertible Notes, net of issuance costs	447,573
Proceeds from exercise of options	5,173	6,713	7,508
Net cash provided by financing activities	414,382	565,469	190,983
Effect of exchange rate changes	(873)	(376)
Net increase in cash and cash equivalents	10,933	12,719	6,660
Cash and cash equivalents - beginning of period	32,742	20,023	13,363
Cash and cash equivalents - end of period	$ 43,675	$ 32,742	20,023
Supplemental disclosures of noncash activities:
Issuance of common stock for cashless warrant exchange			$ 220,944

Overview of Business

Overview of Business	12 Months Ended
	Dec. 31, 2016
Nature of Business and Basis of Presentation [Abstract]
Nature of Business and Basis of Presentation	1. Overview of Business Intercept Pharmaceuticals, Inc. (“Intercept” or the “Company”) is a biopharmaceutical company focused on the development and commercialization of novel therapeutics to treat non-viral, progressive liver diseases, including primary biliary cholangitis (“PBC”), nonalcoholic steatohepatitis (“NASH”), primary sclerosing cholangitis (“PSC”) and biliary atresia. Founded in 2002 in New York, Intercept now has operations in the United States, Europe and Canada.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2016
Basis of Presentation [Abstract]
Basis of Presentation	2. Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Certain reclassifications have been made to prior period amounts in our consolidated statements of operations to conform to the current period presentation. The Company reclassified certain medical affairs costs of $15.5 million from research and development expense to selling, general and administrative expense on the consolidated statements operations during the year ended December 31, 2015. 

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements include the accounts of Intercept and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company has no unconsolidated subsidiaries or investments accounted for under the equity method. Cash and Cash Equivalents The Company considers all highly liquid securities with a maturity of three months or less at acquisition to be cash equivalents. Investment Securities, Available for Sale Investment securities are considered to be available-for-sale and are carried at fair value. Unrealized gains and losses, if any, are reported in other comprehensive income (loss). The cost of investment securities classified as available-for-sale is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in interest income. Realized gains and losses, and declines in value judged to be other-than-temporary, if any, are also included in other income, net. The cost of securities sold is based on the specific identification method. The estimated fair value of the available for sale securities is determined based on quoted market prices or rates for similar instruments. Fair Value of Financial Instruments Financial instruments, including cash and cash equivalents, receivables, accounts payable and accrued liabilities are carried at cost which management believes approximates fair value because of the short term maturity of these instruments. Risks and Uncertainties The Company is subject to risks common to companies in the pharmaceutical industry including failing to secure additional funding, uncertainties related to commercialization of products, and regulatory approval. Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash, cash equivalents and investment securities. The Company currently invests its excess cash primarily in money market funds, U.S. Treasury notes, and high quality, marketable debt instruments of corporations, financial institutions and government sponsored enterprises. The Company has adopted an investment policy that includes guidelines relative to credit quality, diversification and maturities to preserve principal and liquidity. On a consolidated basis, for the year ended December 31, 2016, the Company’s three largest customers (as discussed in more detail below under “Revenue Recognition”) accounted for 49% , 37% and 12% , of the Company’s gross sales, respectively. Accounts Receivable The Company extends credit to customers based on its evaluation of the customer’s financial condition. The Company records receivables for all billings when amounts are due under standard terms. Accounts receivable are stated at amounts due net of applicable prompt pay discounts and other contractual adjustments as well as an allowance for doubtful accounts. The Company assesses the need for an allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due, the customer’s ability to pay its obligation and the condition of the general economy and the industry as a whole. The Company will write off accounts receivable when the Company determines that they are uncollectible. The Company has recorded $9.1 million of accounts receivable as of December 31, 2016 and has no t recorded an allowance for any doubtful accounts as of December 31, 2016. On a consolidated basis, the Company’s three largest customers accounted for 45% , 38% and 14% of the December 31, 2016 accounts receivable balance, respectively. Fixed Assets Fixed assets are stated at cost, and depreciated over the estimated useful life of the assets. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, generally three to seven years. Leasehold improvements are amortized over the shorter of the asset’s useful life or the life of the lease term . Expenditures for maintenance and repairs are charged to expense as incurred. Impairment of Long-Lived Assets Long-lived assets consist of fixed assets. The Company evaluates long-lived assets for impairment when events and circumstances indicate that the carrying amount of an asset or group of assets may not be fully recoverable. Inventory Inventories are stated at the lower of cost or estimated realizable value. The Company determines the cost of inventory using the first-in, first-out, or FIFO, method. The Company capitalizes inventory costs associated with the Company's product after regulatory approval when, based on management's judgment, future commercialization is considered probable and the future economic benefit is expected to be realized; otherwise, such costs are expensed as research and development. The Company periodically analyzes its inventory levels to identify inventory that may expire prior to expected sale or has a cost basis in excess of its estimated realizable value, and writes-down such inventories as appropriate. In addition, the Company's product is subject to strict quality control and monitoring which the Company performs throughout the manufacturing process. If certain batches or units of product no longer meet quality specifications or become obsolete due to expiration, the Company records a charge to cost of sales sold to write down such unmarketable inventory to zero. Convertible Senior Notes The Company’s 3.25% convertible senior notes due 2023 (the “Convertible Notes”) are accounted for in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification (“ASC”) 470, formerly FSP APB 14-1, Accounting for Convertible Debt Instruments That May be Settled in Cash upon Conversion (Including Partial Cash Settlement). ASC Subtopic 470-20 requires the issuer of convertible debt that may be settled in shares or cash upon conversion at the issuer's option, such as these notes, to account for the liability (debt) and equity (conversion option) components separately. The value assigned to the debt component is the estimated fair value, as of the issuance date, of a similar debt instrument without the conversion option. The amount of the equity component (and resulting debt discount) is calculated by deducting the fair value of the liability component from the principal amount of the convertible debt instrument. The resulting debt discount is amortized as additional non-cash interest expense over the expected life of the notes utilizing the effective interest method. Although ASC 470 has no impact on the Company’s actual past or future cash flows, it requires the Company to record non-cash interest expense as the debt discount is amortized. For additional information, see Note 10 – Long-Term Debt.  Revenue Recognition Product Revenue, Net Revenue is recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence that an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed or determinable; and (4) collectability is reasonably assured. When the revenue recognition criteria are not met, we defer the recognition of revenue by recording deferred revenue on the balance sheet until such time that all criteria are met. Beginning in June 2016, subsequent to the U.S. Food and Drug Administration (“FDA”) approval of Ocaliva ® (obeticholic acid or “OCA”) for the treatment of PBC, the Company sells Ocaliva in the United States principally to a limited number of specialty pharmacies which dispense the product directly to patients. The specialty pharmacies are referred to as the Company’s customers. The Company provides the right of return to its customers for unopened product for a limited time before and after its expiration date. Given the Company’s limited sales history for Ocaliva and the inherent uncertainties in estimating product returns, the Company has determined that the shipments of Ocaliva made to its customers thus far do not meet the criteria for revenue recognition at the time of shipment. Accordingly, the Company recognizes revenue when the product is sold through by its customers, provided all other revenue recognition criteria are met. The Company invoices its customers upon shipment of Ocaliva to them and records accounts receivable, with a corresponding liability for deferred revenue equal to the gross invoice price. The Company then recognizes revenue when Ocaliva is sold through as specialty pharmacies dispense product directly to the patients. The Company recognized net sales of Ocaliva of $18.2 million for the year ended December 31, 2016. The Company also recorded $3.9 million in deferred revenues recorded in short-term portion of deferred revenue on its balance sheet, which represents product shipped to distributors, but not sold through as of December 31, 2016. The Company has written contracts with each of its customers and delivery occurs when the customer receives Ocaliva. The Company evaluates the creditworthiness of each of its customers to determine whether collection is reasonably assured. In order to conclude that the price is fixed and determinable, the Company must be able to (i) calculate its gross product revenues from the sales to its customers and (ii) reasonably estimate its net product revenues. The Company calculates gross product revenues based on the wholesale acquisition cost that the Company charges its customers for Ocaliva. The Company estimates its net product revenues by deducting from its gross product revenues (i) trade allowances, such as invoice discounts for prompt payment and customer fees, (ii) estimated government rebates and discounts related to Medicare, Medicaid and other government programs, and (iii) estimated costs of incentives offered to certain indirect customers including patients. Trade Allowances The Company provides invoice discounts on Ocaliva sales to certain of its customers for prompt payment and records these discounts as a reduction to gross product revenues. These discounts are based on contractual terms. Rebates and Discounts The Company contracts with Centers for Medicare & Medicaid Services (“CMS”) and other government agencies to make Ocaliva available to eligible patients. As a result, the Company estimates any rebates and discounts and deducts these estimated amounts from its gross product revenues at the time the revenues are recognized. The Company’s estimates of rebates and discounts are based on the government mandated discounts, which are statutorily-defined and applicable to these government funded programs. These estimates are recorded in accrued liabilities on the condensed consolidated balance sheet. Other Incentives Other incentives that the Company offers to indirect customers include co-pay assistance cards provided by the Company for PBC patients whom reside in states that permit co-pay assistance programs. The Company’s co-pay assistance program is intended to reduce each participating patient’s portion of the financial responsibility for Ocaliva purchase price to a specified dollar amount. The Company estimates each period the amount of co-pay assistance provided to eligible patients based on the terms of the program when product is dispensed by the specialty pharmacies to the patients. These estimates are based on redemption information provided by third party claims processing organizations and are recorded in accrued liabilities on the condensed consolidated balance sheet.  Licensing Revenue  The Company accounts for the development, regulatory and sales milestones within an arrangement in accordance with the milestone method of revenue recognition. This method allows for the recognition of consideration which is contingent on the achievement of a substantive milestone in its entirety in the period the milestone is achieved. Each future milestone is considered substantive if it (i) relates solely to the past performance of the intellectual property to achieve the milestone; (ii) is reasonable relative to all of the deliverables and payment terms in the arrangement; and (iii) is commensurate with either the Company’s performance or the enhanced value of the intellectual property as a result of a specific outcome resulting from the Company’s performance. Research and Development Expenses Research and development costs that do not have alternative future use are charged to expense as incurred. This includes the cost of conducting clinical trials, compensation and related overhead for employees and consultants involved in research and development and the cost of the Company’s manufacturing activities to supply ongoing and future clinical trials and preclinical studies as well as preparations for commercialization of obeticholic acid (“OCA”). For periods prior to the commercial launch of Ocaliva in PBC in June 2016, the manufacturing costs for OCA were expensed as part of research and development. The Company will continue to incur manufacturing costs for commercial supply of OCA in other indications such as NASH prior to their approval.  Stock-based Compensation The Company accounts for stock-based compensation in accordance with Financial Accounting Standards Board's Accounting Standards Codification ("ASC") 718, "Compensation - Stock Compensation" (ASC 718). The Company estimates the fair value of stock options using the Black-Scholes option pricing model on the date of the grant. Restricted stock units and restricted stock awards are valued based on the closing price of the Company’s common stock on the date of the grant. The fair value of equity instruments expected to vest after taking into consideration an estimate of award forfeitures based on actual experience are recognized and amortized on a straight-line basis over the requisite service period of the award. Generally stock options fully vest four years from the grant date and have a term of ten years. The Company recognizes stock-based compensation for consultants on a mark–to-market basis which is updated on a quarterly basis. Warrants to Purchase Common Stock In conjunction with various financing transactions, the Company issued warrants to purchase the Company’s common stock. Certain of the warrants included a so-called “down round” provision that provided for a reduction in the warrant exercise price if there were subsequent issuances of additional shares of common stock for consideration per share less than the per share warrant exercise prices and certain warrants contained a provision that required the underlying shares to be registered upon an initial public offering (“IPO”). These warrants were deemed to be derivative instruments and as such, were recorded as a liability and were marked-to-market at each reporting period using the Black-Scholes option pricing model. The Company estimated the fair values of the warrants at each reporting period using a Black-Scholes option-pricing. Management concluded, under the Company’s facts and circumstances, that the estimated fair values of the warrants using the Black-Scholes option-pricing model approximates, in all material respects, the values determined using a binomial valuation model. The estimates in the Black-Scholes option-pricing model and the binomial valuation model are based, in part, on subjective assumptions, including but not limited to stock price volatility, the expected life of the warrants, the risk free interest rate and the fair value of the common stock underlying the warrants. Changes in the fair value of the common stock warrant liability from the prior period were recorded as a component of other income and expense. Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing net income (loss) attributable to common stockholders (numerator) by the weighted average number of common shares outstanding (denominator) during the period. Diluted net income (loss) per share gives effect to all dilutive potential common shares outstanding during the period including stock options, restricted stock units (“RSUs”) and warrants using the treasury stock method. Income Taxes The Company utilizes the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement carrying amounts and tax bases of assets and liabilities using enacted tax rates in effect for years in which the temporary differences are expected to reverse. The Company establishes a valuation allowance when it believes it is more likely than not that deferred tax assets will not be realized. The Company determines the need for a valuation allowance by assessing the probability of realizing deferred tax assets, taking into consideration all available positive and negative evidence, including historical operating results, expectations of future taxable income, carryforward periods available, various income tax strategies and other relevant factors. Significant judgment is required in making this assessment and to the extent future expectations change, the Company would have to assess the recoverability of its deferred assets at that time. At December 31, 2016 and 2015, the Company maintained a full valuation allowance on its deferred tax assets. At any one time the Company’s tax returns for numerous tax years are subject to examination by U.S. Federal, state, and foreign taxing jurisdictions. The impact of an uncertain tax position taken or expected to be taken on an income tax return must be recognized in the financial statements at the largest amount that is more likely than not to be sustained. An uncertain income tax position will not be recognized in the financial statements unless it is more likely than not to be sustained. At December 31, 2016 and 2015, the Company had no reserves for unrecognized tax benefits. Segments The Company operates in one segment. The Company is a biopharmaceutical company focused on discovering, developing and commercializing treatments for non-viral, progressive liver diseases. Recent Accounting Pronouncements In November 2015, the FASB issued Accounting Standards update (“ASU”) 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes, which requires that deferred tax assets and liabilities, as well as any related valuation allowance, be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2016. Early adoption is permitted and may be applied either retrospectively or on a prospective basis. The Company has early adopted this ASU effective with its annual reporting period ended December 31, 2016 on a prospective basis. The adoption did not have a material impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (“ASU 2016-02”) which supersedes Topic 840, Leases. ASU 2016-02 requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all the leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. For leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients primarily focused on leases that commenced before the effective date of Topic 842, including continuing to account for leases that commence before the effective date in accordance with previous guidance, unless the lease is modified. The Company is evaluating the impact of the adoption of the standard on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which is intended to improve the accounting for share-based payment transactions as part of the FASB’s simplification initiative. The ASU changes certain aspects of the accounting for share-based payment award transactions, including: (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flows; (3) forfeitures; (4) minimum statutory tax withholding requirements; and (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax withholding purposes. The ASU is effective for fiscal years beginning after December 15, 2016, and interim periods within those years for public business entities. We do not expect the adoption of this updated standard to have a material impact on our consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements of FASB ASC Topic 605, Revenue Recognition and most industry-specific guidance throughout the ASC, resulting in the creation of FASB ASC Topic 606, Revenue from Contracts with Customers. ASU 2014-09 requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. This ASU provides alternative methods of adoption. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers, Deferral of the Effective Date ("ASU 2015-14"). ASU 2015-14 defers the effective date of ASU 2014-09 by one year to December 15, 2017 for fiscal years, and interim periods within those years, beginning after that date and permits early adoption of the standard, but not before the original effective date for fiscal years beginning after December 15, 2016. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08") clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing, clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improves the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). The effective date and transition requirements for ASU 2016-08 and ASU 2016-10 are the same as the effective date and transition requirements for ASU 2014-09. The Company is currently assessing the potential impact of adopting ASU 2014-09, ASU 2016-08 and ASU 2016-10 on its financial statements and related disclosures. On August 27, 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern (“ASU 2014-15”), which requires an entity to evaluate whether conditions or events, in the aggregate, raise substantial doubt about the entity's ability to continue as a going concern for one year from the date the financial statements are issued or are available to be issued. The guidance became effective January 1, 2017. The adoption of ASU 2014-15 is not expected to have an impact on our consolidated financial position, results of operations or cash flows. 

Significant Agreements

Significant Agreements	12 Months Ended
	Dec. 31, 2016
Significant Agreements [Abstract]
Significant Agreements	4. Significant Agreements Sumitomo Dainippon Pharma Co., Ltd. (Sumitomo Dainippon) In March 2011, the Company entered into an exclusive license agreement with Sumitomo Dainippon to research, develop and commercialize OCA as a thera peutic for the treatment of PBC and NASH in Japan and China (excluding Taiwan). Under the terms of the license agreement, the Company received an up-front payment from Sumitomo Dainippon of $15.0 million and may be eligible to receive additional milestone payments of up to an aggregate of approximately $30.0 million in development milestones based on the initiation or completion of clinical trials, $70.0 million in regulatory approval milestones and $200.0 million in sales milestones. The regulatory approval milestones include $15.0 million for receiving marketing approval of OCA for NASH in Japan, $10.0 million for receiving marketing approval of OCA for NASH in China, and $5.0 million for receiving marketing approval of OCA for PBC in the United States, which was achieved upon the FDA approval of Ocaliva for the treatment of PBC in May 2016. As of December 31, 2016, the Company had achieved $6.0 million of the development milestones under its collaboration agreement with Sumitomo Dainippon. The sales milestones are based on aggregate sales amounts of OCA in the Sumitomo Dainippon territory and include $5.0 million for achieving net sales of $50.0 million, $10.0 million for achieving net sales of $100.0 million, $20.0 million for achieving net sales of $200.0 million, $40.0 million for achieving net sales of $400.0 million and $120.0 million for achieving net sales of $1.2 billion. The Company has determined that each potential future development, regulatory and sales milestone is substantive. In May 2014, Sumitomo Dainippon exercised its option under the license agreement to add Korea as part of its licensed territories and paid the Company a $1.0 million up-front fee. Sumitomo Dainippon has the option to add several other Asian countries to its territory to pursue OCA for additional indications. Sumitomo Dainippon will be responsible for the costs of developing and commercializing OCA in its territories. Sumitomo Dainippon is also required to make royalty payments ranging from the tens to the twenties in percent based on net sales of OCA products in the Sumitomo Dainippon territory. The Company evaluated the license agreement with Sumitomo Dainippon and determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company’s substantive performance obligations under this license include an exclusive license to its technology, technical and scientific support to the development plan and participation on a joint steering committee. The Company determined that these performance obligations represent a single unit of accounting, since, initially, the license does not have stand-alone value to Sumitomo Dainippon without the Company’s technical expertise and steering committee participation during the development of OCA. This development period is currently estimated as continuing through June 2020 and, as such, the up-front payment and payments made in respect of the Korea option are being recognized ratably over this period. During the year ended December 31, 2016 and 2015, the Company recorded revenue of approximately $6.8 million and $2.8 million, respectively.  

Cash, Cash Equivalents, and Inv

Cash, Cash Equivalents, and Investments	12 Months Ended
	Dec. 31, 2016
Cash, Cash Equivalents, and Investments [Abstract]
Cash, Cash Equivalents, and Investments	5. Cash, Cash Equivalents, and Investments The following table summarizes the Company’s cash, cash equivalents and investments as of December 31, 2016 and December 31, 201 5:     As of December 31, 2016  Gross Gross  Amortized Cost Unrealized Unrealized Fair Value  Gains Losses   (in thousands)  Cash and cash equivalents:  Cash and money market funds $ 43,675 $ - $ - $ 43,675  Investment securities:  Commercial paper 66,185 - (71) 66,114  Corporate debt securities 554,847 14 (1,443) 553,418  U.S. government and agency securities 26,254 - (76) 26,178  Total investments 647,286 14 (1,590) 645,710  Total cash, cash equivalents and investments $ 690,961 $ 14 $ (1,590) $ 689,385     As of December 31, 2015  Gross Gross  Amortized Cost Unrealized Unrealized Fair Value  Gains Losses   (in thousands)  Cash and cash equivalents:  Cash and money market funds $ 32,742 $ - $ - $ 32,742  Investment securities:  Commercial paper 1,993 - (3) 1,990  Corporate debt securities 529,368 2 (1,720) 527,650  U.S. government and agency securities 65,854 1 (182) 65,673  Total investments 597,215 3 (1,905) 595,313  Total cash, cash equivalents and investments $ 629,957 $ 3 $ (1,905) $ 628,055  The Company held a total of two positions as of December 31, 2016 and no positions as of December 31, 2015 that were in a n unrealized loss position for more than twelve months.  The fair value for the Company’s available-for-sale investments, which have been in an unrealized loss position for less than and longer than 12 months is as follows :        As of December 31, 2016  Less than 12 months 12 Months or greater Total  (in thousands)  Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses  Corporate debt securities $ 341,823 $ (510) $ 178,818 $ (933) $ 520,641 $ (1,443)  U.S. government and agency securities 19,479 (30) 6,699 (46) 26,178 (76)  Commercial paper 66,114 (71) - - 66,114 (71)  Total $ 427,416 $ (611) $ 185,517 $ (979) $ 612,933 $ (1,590)    As of December 31, 2015  Less than 12 months 12 Months or greater Total  (in thousands)  Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses  Corporate debt securities $ 316,036 $ (551) $ 201,676 $ (1,169) $ 517,712 $ (1,720)  Commercial paper 15,793 (30) 44,879 (152) 60,672 (182)  U.S. government and agency securities 1,990 (3) - - 1,990 (3)  Total $ 333,819 $ (584) $ 246,555 $ (1,321) $ 580,374 $ (1,905)  

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2016
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	6. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following:       December 31,  2016 2015  (in thousands)  Prepaid expenses and other receivables $ 6,145 $ 9,947  Interest receivable 3,209 3,304  Contract receivable - 47  Refundable tax credits - 340  Prepaid expenses and other current assets $ 9,354 $ 13,638  

Fixed Assets, Net

Fixed Assets, Net	12 Months Ended
	Dec. 31, 2016
Fixed Assets, Net [Abstract]
Fixed Assets, Net	7. Fixed Assets, Net Fixed assets are stated at cost and depreciated or amortized using the straight-line method based on useful lives as follows:       Useful lives December 31,  (Years) 2016 2015  (in thousands)  Office equipment and software 3 $ 4,942 $ 2,188  Leasehold improvements Over life of lease 6,668 6,818  Furniture and fixtures 7 4,202 3,402  Subtotal 15,812 12,408  Less: accumulated depreciation (4,517) (2,361)  Fixed assets, net $ 11,295 $ 10,047 Depreciation expense for the years ended December 31, 2016, 2015 and 2014 was approximately $3.8 million, $1.7 million, and $443,000 , respectively .

Inventory

Inventory	12 Months Ended
	Dec. 31, 2016
Inventory [Abstract]
Inventory	8. Inventory Inventories are stated at the lower of cost or market. Inventories consist of the following:     December 31,  2016 2015  (in thousands)  Work-in-process $ 2,207 $ -  Finished goods 72 -  Inventory, net $ 2,279 $ -  

Accounts Payable, Accrued Expen

Accounts Payable, Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2016
Accounts Payable, Accrued Expenses and Other Liabilities [Abstract]
Accounts Payable, Accrued Expenses and Other Liabilities	9. Accounts Payable, Accrued Expenses and Other Liabilities Accounts payable, accrued expenses and other liabilities consisted of the following:       December 31,  2016 2015  (in thousands)  Accounts payable $ 6,722 $ 4,170  Accrued employee compensation 19,287 11,414  Accrued contracted services and other 39,542 30,007  Accounts payable, accrued expenses and other liabilities $ 65,551 $ 45,591  

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2016
Long-Term Debt [Abstract]
Long-Term Debt	10 . Long-Term Debt Debt, net of discounts and deferred financing costs, consists of the following:      December 31,  2016 2015  (in thousands)  Long-term debt $ 341,356 $ -  Less current portion - -  Long-term debt outstanding $ 341,356 $ -  On July 6, 2016, the Company issued $460.0 million aggregate principal amount of the Convertible Notes. The Company received net proceeds of $447.6 million after deducting underwriting discounts and estimated offering expenses o f approximately $12.4 million. The Company used approximately $38.4 million of the net proceeds from the offering to fund the payment of the cost of the capped call transactions that were entered into in connection with the issuance of the Convertible Notes. The Convertible Notes are senior unsecured obligations of the Company. Interest is payable semi-annually on January 1 and July 1 of each year, beginning on January 1, 2017. The Convertible Notes mature on July 1, 2023, unless earlier repurchased, redeemed or converted. The Convertible Notes are convertible at the option of holders, under certain circumstances and during certain periods, into cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at the Company’s election. The initial conversion rate of the Convertible Notes is 5.0358 shares of the Company’s common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of approximately $198.58 per share of the Company’s common stock. The conversion rate is subject to adjustment upon the occurrence of certain events. The Company may redeem for cash all or part of the Convertible Notes, at its option, on or after July 6, 2021 , under certain circumstances at a redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. The capped call transactions are expected generally to reduce the potential dilution upon conversion of the Convertible Notes in the event that the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, is greater than the strike price of the capped call transactions, which initially corresponds to the conversion price of the Convertible Notes, and is subject to anti-dilution adjustments generally similar to those applicable to the conversion rate of the Convertible Notes. The cap price of the capped call transactions is initially $262.2725 per share, and is subject to certain adjustments under the terms of the capped call transactions. If, however, the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, exceeds the cap price of the capped call transactions, there would nevertheless be dilution upon conversion of the Convertible Notes to the extent that such market price exceeds the cap price of the capped call transactions. In accordance with ASC Subtopic 470-20, the Company used an effective interest rate of 8.4% to determine the liability component of the Convertible Notes. This resul ted in the recognition of $334.4 million as the liability component of the Convertible Notes and the recognition of the residual $113.1 million as the debt discount with a corresponding increase to additional paid-in capital for the equity component of the Convertible Notes. Interest expense was $14.2 million for the year ended December 31 , 2016 related to the Convertible Notes. Accrued interest on the Converti ble Notes was approximately $7.3 million as of December 31 , 2016. The Company recor ded debt issuance costs of $12.4 million, which are being amortized using the effe ctive interest method. As of December 31, 2016, $11.7 million of debt issuance cos ts are recorded on the consolidated balance sheet in Long-Term Debt, in accordance with ASU 2015-03. As of December 31 , 2016, the Company had outstanding borrowings of $460.0 million related to the Convertible Notes.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Measurements [Abstract]
Fair Value Measurements	11. Fair Value Measurements The carrying amounts of the Company’s receivables and payables approximate their fair value due to their short maturities. Accounting principles provide guidance for using fair value to measure assets and liabilities. The guidance includes a three level hierarchy of valuation techniques used to measure fair value, defined as follows: · Unadjusted Quoted Prices — The fair value of an asset or liability is based on unadjusted quoted prices in active markets for identical assets or liabilities (Level 1). · Pricing Models with Significant Observable Inputs — The fair value of an asset or liability is based on information derived from either an active market quoted price, which may require further adjustment based on the attributes of the financial asset or liability being measured, or an inactive market transaction (Level 2). · Pricing Models with Significant Unobservable Inputs — The fair value of an asset or liability is primarily based on internally derived assumptions surrounding the timing and amount of expected cash flows for the financial instrument. Therefore, these assumptions are unobservable in either an active or inactive market (Level 3).  The Company considers an active market as one in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Conversely, the Company views an inactive market as one in which there are few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, non-performance risk, or that of a counterparty, is considered in determining the fair values of liabilities and assets, respectively. The Company’s cash deposits and money market funds are classified within Level 1 of the fair value hierarchy because they are valued using bank balances or quoted market prices. Investments are classified as Level 2 instruments based on market pricing and other observable inputs.  Financial assets carried at fair value are classified in the tables below in one of the three categories described above:      Fair Value Measurements Using  Total Level 1 Level 2 Level 3  (in thousands)  December 31, 2016  Assets:  Money market funds $ 11,755 $ 11,755 $ - $ -  Available for sale securities:  Commercial paper 66,114 - 66,114 -  Corporate debt securities 553,418 - 553,418 -  U.S. government and agency securities 26,178 - 26,178 -  Total financial assets: $ 657,465 $ 11,755 $ 645,710 $ -   December 31, 2015  Assets:  Money market funds $ 4,826 $ 4,826 $ - $ -  Available for sale securities:  Commercial paper 1,990 - 1,990 -  Corporate debt securities 527,650 - 527,650 -  U.S. government and agency securities 65,673 - 65,673 -  Total financial assets: $ 600,139 $ 4,826 $ 595,313 $ -  The estimated fair value of marketable debt securities (commercial paper, corporate debt securities, U.S. government and agency securities, and municipal securities) as of December 31, 2016 and 2015, respectively, by contractual maturity, are as follows:      Fair Value as of December 31,  2016 2015  (in thousands)  Due in one year or less $ 456,184 $ 343,758  Due after one year through 2 years 189,526 251,555  Total investments in debt securities $ 645,710 $ 595,313 Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.

Stockholders' Equity and Prefer

Stockholders' Equity and Preferred Stock	12 Months Ended
	Dec. 31, 2016
Stockholders' Equity and Preferred Stock [Abstract]
Stockholders' Equity and Preferred Stock	12. Stockholders’ Equity and Preferred Stock Common Stock As of December 31, 2016 and December 31, 2015, the Company had 45,000,000 and 35,000,000 authorized shares of common stock, $0.001 par value per share , respectively. At the 2016 annual meeting of stockholders held on July 19, 2016, the Company’s stockholders approved an amendment to the Company’s restated certificate of incorporation, as amended, to increase the number of authorized shares of common stock from 35,000,000 shares to 45,000,000 shares. In February 2015, the Company completed a public offering of 1,150,000 shares of its common stock at a public offering price of $176.00 per share. The shares were registered pursuant to a registration statement on Form S-3. After underwriting discoun ts and commissions and offering expenses, the Company received net proceeds of approximately $191.7 million.  In April 2015, the Company completed a public offering of 1,330,865 shares of its common stock pursuant to a registration statement on Form S-3. After underwriting discounts and commissions and offering expenses, the Company received net proceeds of approximately $367.1 million. Dividends The holders of common stock are entitled to receive dividends from time to time as declared by the board of directors. The Company has not declared any cash dividends on its common stock, and does not anticipate paying any cash dividends on its common stock in the foreseeable future. The Company intends to retain all available funds and any future earnings to fund the development and expansion of its business. Any future determination to pay dividends will be at the discretion of the board of directors and will depend upon a number of factors, including the results of operations, financial condition, future prospects, contractual restrictions, restrictions imposed by applicable law and other factors the board of directors deems relevant. Voting The holders of shares of common stock are entitled to one vote for each share held with respect to all matters voted on by the stockholders of the Company. Preferred Stock As of December 31, 2016 and 2015, the Company had 5,000,000 authorized shares of preferred stock, $0.001 par value per share, of which no ne are issued.

Stock Compensation

Stock Compensation	12 Months Ended
	Dec. 31, 2016
Stock Compensation [Abstract]
Stock Compensation	13. Stock Compensation The 2012 Equity Incentive Plan (2012 Plan) became effective upon the pricing of the IPO in October 2012. At the same time, the 2003 Stock Incentive Plan (2003 Plan) was terminated and 555,843 shares available under the 2003 Plan were added to the 2012 Plan. The estimated fair value of the options that have been granted under the 2003 and 2012 Plans is determined utilizing the Black-Scholes option-pricing model at the date of grant. The fair value of the RSUs and RSAs that have been granted under the 2012 Plan is determined utilizing the closing stock price on the date of grant. There were approximately 1.5 million and 1.2 million shares available for grant remaining under the 2012 Plan at December 31, 2016 and 2015, respectively. On January 1, 2016 and 2015 , the numbers of shares reserved for issuance under the 2012 Plan was increased by 976,101 , and 856,609 shares, respectively, as a result of the automatic increase in shares reserved pursuant to the terms thereof. Stock Options The Company estimated the fair value of stock options granted in the periods presented using a Black-Scholes option-pricing model utilizing the following assumptions:       Years Ended December 31,  2016 2015 2014  Volatility 60 - 66% 61 - 90% 70 - 150%  Expected term (in years) 5.1 - 10.0 5.1 - 7.0 4.0 - 7.0  Risk-free rate 1.1 - 2.4% 0.2 - 2.2% 1.3 - 2.7%  Expected dividend yield — % — % — %  The stock price for options granted prior to the IPO was determined based on a valuation of the Company’s common stock. For options granted after the IPO, the stock price is the closing price on the date of grant. The risk-free interest rate was based on the rate for U.S. Treasury securities at the date of grant with maturity dates approximately equal to the expected life at the grant date. The Company uses historical data to estimate the expected term of the option; separate groups of employees that have similar historical exercise behavior are considered separately for valuation purposes. The expected term of options granted represents the period of time the options are expected to be outstanding. The expected volatility was estimated based on historical volatility information of peer companies that are publicly available. The Company’s combined outstanding employee and non-employee option activity for the period from December 31, 2015 through December 31, 2016 is summarized as follows:     Weighted  Average  Number Weighted Remaining Aggregate  of Shares Average Contractual Intrinsic Value  (in thousands) Exercise Price Term (years) (in thousands)  Outstanding at December 31, 2015 1,348 $ 108.49 7.3 $ 91,402  Granted 481 $ 112.82 6.1 $ -  Exercised (185) $ 28.07 - $ 21,987  Cancelled/forfeited (81) $ 129.91 - $ -  Expired (10) $ 177.02 - $ -  Outstanding at December 31, 2016 1,553 $ 117.80 7.4 $ 48,308  Expected to vest 1,531 $ 117.40 7.3 $ 48,199  Exercisable 797 $ 90.73 6.1 $ 43,156  The aggregate intrinsic value of options is calculated as the difference between the exercise price of the underlying options and the deemed fair value of the Company’s common stock for those shares that had exercise prices lower than the deemed fair value of the Company’s common stock. As of December 31, 2016, the total compensation cost related to non-vested option awards not yet recognized is approximately $38.9 million with a weighted average remaining vesting period of 2.72 years. The weighted-average grant date fair value of options granted during the year ended December 31, 2016 is $64.80 . The total fair value of shares underlying options that vested in 2016 was $18.2 million. In April 2014, the Company issued 57,063 performance-based options to certain employees to purchase common stock that will vest upon the achievement of certain regulatory milestones related to OCA at future dates. In November 2014, the Company issued an additional 10,839 performance-based options that will vest upon the achievement of the same regulatory milestones noted above. As of both December 31, 2016 and 2015, the achievement of the milestones was not deemed to be probable and no stock-based compensation expense was recognized for these performance-based options. Restricted Stock Units and Awards The following table summarizes the aggregate activities in relation to RSU and RSA activity for the years ended December 31, 2016 and 2015 :    Number of Shares (in thousands) Weighted Average Grant Date Fair Value  Non-vested Shares at December 31, 2015 193 $ 183.19  Granted 312 $ 117.63  Exercised (92) $ 161.03  Cancelled/forfeited (32) $ 159.22  Non-vested Shares at December 31, 2016 381 $ 136.89  As of December 31, 2016, there was $41.6 million of unrecognized compensation expense related to unvested RSUs and RSAs, which is expected to be recognized over a weighted average of 2.47 years.  In October 2016, the Company issued 11,725 shares of restricted stock awards to a certain employee that will vest upon the achievement of certain regulatory and commercial mileston es. For the year ended December 31, 2016, no stock-based compensation expense was recognized for these awards.  Stock-based compensation expense has been reported in our statements of operations as follows:     Years Ended December 31,  2016 2015 2014  (in thousands)   Selling, general and administrative $ 32,073 $ 16,223 $ 8,418  Research and development 14,132 17,966 11,709  Total stock-based compensation $ 46,205 $ 34,189 $ 20,127

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Taxes [Abstract]
Income Taxes	 14. Income Taxes The components of loss before income taxes for the years ended December 31, 2016, 2015 and 2014 includes the following:    Years Ended December 31,  2016 2015 2014  (in thousands)  United States $ (154,812) $ (116,349) $ (283,226)  Foreign (258,018) (110,080) -  Total $ (412,830) $ (226,429) $ (283,226)  Income tax expense (benefit) differed from the amounts computed by applying the U.S. Federal income tax rate of 34% to loss before income taxes as a result of the following:     Years Ended December 31,  2016 2015 2014  (in thousands)  Computed "expected" tax benefit $ (140,362) $ (76,986) $ (96,297)  State taxes, net of U.S. Federal benefit - - -  U.S. Federal valuation allowance 40,377 40,973 36,052  Stock-based compensation 5,161 (3,230) 342  Officer compensation 50 (1,778) 1,784  Foreign tax rate differences 94,901 37,427 -  Intercompany license of intellectual property - 3,400 -  Mark to market warrant income - - 58,083  Other (127) 194 36  Total $ - $ - $ -  The tax effects of temporary differences that give rise to the deferred tax assets and liabilities at December 31, 2016 and 2015 are presented below:     December 31,  2016 2015  (in thousands)  Deferred tax assets:  Net operating loss and other carryforwards $ 220,175 $ 127,364  Stock compensation 17,166 9,929  Deferred revenue 2,400 2,846  Accrued compensation 4,775 3,058  Accrued expense 1,841 1,447  Intellectual property 3,570 1,775  Other 759 802  Deferred tax assets before valuation allowance 250,686 147,221  Valuation allowance (223,383) (147,221)  Total deferred tax assets 27,303 -  Deferred tax liabilities:  Convertible Note (27,303) -  Total deferred tax liabilities (27,303) -  Net deferred tax asset (liability) $ - $ -  Net Operating Losses As of December 31, 2016 and 2015, the Company had net operating loss (“NOLs”) carryforwards for U.S. Federal income tax purposes of $562.3 million and $454.4 million, respectively, which expire between 2024 and 2036 . The Company also has certain state and foreign NOLs in varying amounts depending on the different state and foreign tax laws. The U.S. Federal NOLs of $562.3 million and $454.4 million include approximately $167.9 million and $151.0 million, respectively, of excess tax benefits related to stock-based payments that are not recognized as a deferred tax asset. The benefit of these deductions will be recognized through additional paid-in capital at the time the tax deduction results in a reduction of current taxes payable. The Company’s ability to utilize its NOLs may be limited under Section 382 of the Internal Revenue Code or similar rules. The Section 382 limitations apply if an “ownership change” occurs. Generally, an ownership change occurs when certain shareholders increase their aggregate ownership by more than 50 percentage points over their lowest ownership percentage in a testing period (typically three years). The Company has evaluated whether one or more ownership changes under Section 382 have occurred since its inception and have determined that there have been at least two such changes. Although the Company believes that these ownership changes have not resulted in material limitations on its ability to use these NOLs, its ability to utilize these NOLs may be limited due to future ownership changes or for other reasons. Additionally, tax laws limit the time during which NOLs and certain other tax attributes may be utilized against future taxes. As a result, the Company may not be able to take full advantage of its carryforwards for U.S. Federal, state, and foreign tax purposes. Valuation Allowance At December 31, 2016 and 2015, the Company maintained a full valuation allowance on its deferred tax assets since it has not yet achieved sustained profitable operations. As a result, the Company has not recorded any income tax benefit since its inception. In 2016, the valuation allowance for deferred tax assets increased by approximately $76.2 million. This includes an increase of $40.4 million, $7.0 million, and $57.8 million for U.S. Federal, state, and foreign tax, respectively, partially offset by a decrease of $29.0 million to equity. The decrease to equity primarily related to the U.S. Federal and state impact of the equity component associated with the Convertible Notes. Unrecognized Tax Benefits At December 31, 2016 and 2015, the Company had no reserves for unrecognized tax benefits. The Company and its subsidiaries are subject to taxation in the U.S. and various foreign jurisdictions. Of the major jurisdictions, the Company is subject to examination in: the United States for U.S. Federal purposes for 2013 and forward and generally for state purposes for 2012 and forward; and the United Kingdom for 2014 and forward. However, NOLs are subject to audit in any tax year in which those losses are utilized, notwithstanding the year of origin. The Company's U.S. Federal tax return for the year ended December 31, 2014 is currently under audit by the Internal Revenue Service.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2016
Commitments [Abstract]
Commitments	15. Commitments Facility Leases In May 2014, the Company entered into a lease agreement with The Irvine Company LLC for approximately 47,000 square feet in San Diego for office space. The lease term commenced in September 2014 and is scheduled to end in September 2019; however, the Company has an option to further extend the lease for an additional five year term at market rates prevailing at such time. The rent for the first year was approximately $875,000 without giving effect to rent abatements and the rent will gradually increase every 12 months during the lease term. During the first nine months, the Company received a partial rent abatement from the landlord. The landlord provided the Company with an allowance of approximately $2.4 million for improvements to the office space. In January 2016, Intercept Pharma Europe Ltd. (IPEL), a wholly owned subsidiary of the Company, entered into an underlease with Performing Right Society, Ltd., for office space in the King’s Cross area of London, United Kingdom. The Company is the guarantor to the underlease. The underlease provided IPEL with 8,549 square feet of space. The lease term is anticipated to end on May 31, 2024. The annual rent is approximately £726,665 (or approximately $1.0 million), payable quarterly. IPEL is also required to pay VAT on the rent. IPEL is responsible for a portion of the insurance, certain service charges and taxes for the building based on the floor area rented by them. In February 2016, the Company entered into a sublease with Restoration Hardware, Inc. for additional office space in New York City. The sublease provided the Company with an additional 10,785 square feet of space. The lease term is anticipated to end in July 2021. The annual rent is approximately $1.0 million payable monthly. The Company is also responsible for its proportionate share of increases in operating expenses beginning January 2017 as well as its proportionate share of increases in real estate taxes over the average of the 2015/2016 and 2016/2017 fiscal years.  On December 7, 2016, the Company entered into lease agreements relating to the Company’s new global corporate headquarters in the Hudson Yards development site in New York, New York. The leases will provide the Company with shorter term office space in 10 Hudson Yards (the “10 Building”) and longer term office space in 55 Hudson Yards (the “55 Building”).  The lease for the 10 Building will initially provide the Company with approximately 49,000 square feet of space consisting of the entire 37th floor and a portion of the 40th floor of the 10 Building (the “10 Lease”). The expiration date of the 10 Lease as it relates to the 37th floor premises is June 30, 2021. The expiration date of 10 Lease as it relates to the 40th floor premises (the “40th Floor Expiration Date”) shall be the earlier to occur of (a) the date that is 285 days after the possession date under the 55 Lease (as defined below), which may be extended pursuant to the terms of the 55 Lease; (b) the date that the Company legally occupies the premises in the 55 Building (as defined below); and (c) June 30, 2021. The 10 Lease contains customary default provisions, including, without limitation, those relating to payment defaults, performance defaults, events of bankruptcy and customary indemnification provisions. The 10 Lease provides for annual fixed rental payments of approximately (i) $5.2 million per year for the period commencing in April 2017 and ending on the day immediately preceding the 40th Floor Expiration Date and (ii) $3.5 million per year commencing on the 40th Floor Expiration Date and ending on June 30, 2021. In addition to its fixed rent obligations, the Company is obligated to pay its percentage share for customary escalations for operating expenses attributable to the 10 Building and the Hudson Yards development, taxes and tax-related payments. The lease for the 55 Building will provide the Company with approximately 85,000 square feet of space consisting of the 23rd through 25th floors of the 55 Building (the “55 Lease”). The 55 Lease will expire on the last day of the calendar month in which the 15th anniversary of the day preceding the Rent Commencement Date (as defined below) falls. Under the 55 Lease, the Company has an option to renew the term of the 55 Lease either for (i) two additional terms of five years each or (ii) one additional ten-year term. In addition, the 55 Lease contains customary default provisions, including, without limitation, those relating to payment defaults under the 55 Lease, performance defaults under the 55 Lease, events of bankruptcy and customary indemnification provisions. The 55 Lease provides for annual fixed rental payments of approximately (i) $7.9 million per year for the period commencing on the date that is 12 months after the Company takes possession of its premises in the 55 Building (the “Rent Commencement Date”) and ending on the day immediately preceding the 5th anniversary of the Rent Commencement Date; (ii) $8.7 million per year for the period commencing on 5th anniversary of the Rent Commencement Date and ending on the day immediately preceding the 10th anniversary of the Rent Commencement Date; and (iii) $9.6 million per year for the period commencing on 10th anniversary of the Rent Commencement Date and ending upon the expiration date of the 55 Lease. In addition to its fixed rent obligations, the Company is obligated to pay (x) certain incremental construction costs incurred by the landlord on behalf of the Company and (y) its percentage share for customary escalations for operating expenses attributable to the 55 Building and the Hudson Yards development, taxes and tax-related payments.  Rent expense under operating leases for facilities for the years ended December 31, 2016, 2015 and 2014 was approximately $5.5 million, $3.8 million, and $1.7 million, respectively. As of December 31, 2016, minimum operating lease payments under non-cancelable leases, as amended, are as follows:     Year Ending December 31, Amount  (in thousands)  2017 $ 9,191  2018 9,383  2019 16,159  2020 15,331  2021 12,746  Thereafter 107,076  Total future minimum operating lease payments $ 169,886    Purchase Commitments  The Company enters into license and research and development agreements with universities and other third parties. The Company enters into contracts in the normal course of business with contract research organizations for clinical trials, clinical and commercial supply manufacturing, with vendors for preclinical research studies and for other services and products for operating purposes. The agreements generally provide for termination within 90 days of notice. Such agreements are cancelable contracts and not included as purchase commitments. The Company has included as purchase obligations the Company’s commitments under agreements to the extent they are quantifiable and are not cancelable, which is approximately $11.9 million as of December 31, 2016.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	16. Related Party Transactions In connection with the April 2014 secondary offering, pursuant to the third amended and restated stockholders agreement, the Company reimbursed the selling stockholders for the expenses related to the offering (other than any underwriting discounts and commissions), including approximately $70,000 for the legal fees of the selling stockholders.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2016
Net Loss Per Share [Abstract]
Net Loss Per Share	17. Net Loss Per Share The following table presents the historical computation of basic and diluted net loss per share:       Years Ended December 31,  2016 2015 2014  (in thousands, except per share amounts)  Historical Net loss per share  Numerator:  Net loss attributable to common stockholders $ (412,830) $ (226,429) $ (283,226)  Denominator:  Weighted average shares outstanding, basic and diluted 24,663 23,694 20,784  Net loss per share, basic and diluted $ (16.74) $ (9.56) $ (13.63)  The following potentially dilutive securities have been excluded from the computations of diluted weighted average shares outstanding as of December 31, 2016, 2015 and 2014, as they would have been anti-dilutive:       December 31,  2016 2015 2014  (in thousands)  Options 1,553 1,348 1,436  Restricted stock units 382 193 119  Total 1,935 1,541 1,555  

Quarterly Financial Data (unaud

Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	18. Quarterly Financial Data (unaudited) The following table summarizes the unaudited quarterly financial data for the years ended December 31, 2016 and 2015;        Quarters Ended  March 31, June 30, September 30, December 31, Total  2016 (in thousands, except for per share amounts)  Revenues $ 445 $ 5,520 $ 5,177 $ 13,809 $ 24,951  Operating loss (127,400) (78,095) (83,036) (114,007) (402,538)  Net loss (126,674) (77,299) (88,815) (120,042) (412,830)  Net loss per common share - basic and diluted $ (5.17) $ (3.14) $ (3.59) $ (4.84)   2015  Revenues $ 1,447 $ 445 $ 445 $ 445 $ 2,782  Operating loss (39,658) (48,824) (51,784) (88,890) (229,156)  Net loss (39,386) (47,894) (50,896) (88,253) (226,429)  Net loss per common share - basic and diluted $ (1.78) $ (1.99) $ (2.10) $ (3.62)  

Litigation

Litigation	12 Months Ended
	Dec. 31, 2016
Litigation [Abstract]
Litigation	19. Litigation On February 21, 2014 and February 28, 2014 , purported shareholder class actions, styled Scot H. Atwood v. Intercept Pharmaceuticals, Inc. et al. and George Burton v. Intercept Pharmaceuticals, Inc. et al. , respectively, were filed in the United States District Court for the Southern District of New York , naming the Company and certain of its officers as defendants. These lawsuits were filed by stockholders who claim to be suing on behalf of anyone who purchased or otherwise acquired the Company’s securities between January 9, 2014 and January 10, 2014.  The lawsuits alleged that the Company made material misrepresentations and/or omissions of material fact in its public disclosures during the period from January 9, 2014 to January 10, 2014, in violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder. The alleged improper disclosures relate to the Company’s January 9, 2014 announcement that the FLINT trial had been stopped early based on a pre-defined interim efficacy analysis. Specifically, the lawsuits claimed that the January 9, 2014 announcement was misleading because it did not contain information regarding certain lipid abnormalities seen in the FLINT trial in OCA-treated patients compared to placebo. On April 22, 2014, two individuals each moved to consolidate the cases and a lead plaintiff was subsequently appointed by the Court. On June 27, 2014, the lead plaintiff filed an amended complaint on behalf of the putative class as contemplated by the order of the Court. The lead plaintiff was seeking unspecified monetary damages on behalf of the putative class and an award of costs and expenses, including attorneys’ fees. On August 14, 2014, the defendants filed a motion to dismiss the complaint. Oral arguments on the motion to dismiss were held on February 24, 2015. On March 4, 2015, the defendants’ motion to dismiss was denied by the Court. The defendants answered the amended complaint on April 13, 2015. On July 15, 2015, the plaintiff moved for class certification and appointment of class representatives and class counsel. On September 14, 2015, the defendants opposed the plaintiff’s class certification motion. The plaintiff filed its reply to the defendants’ opposition on October 14, 2015, to which the defendants filed a sur-reply on November 10, 2015. Oral arguments on the class certification motion were held on January 20, 2016. On May 2, 2016, the defendants reached an agreement with the lead plaintiff to seek Court approval of a proposed resolution. The plaintiffs moved for preliminary approval of the proposed settlement on May 5, 2016. On May 23, 2016, the Court entered an order preliminarily approving the settlement. The Court ordered that notice be provided to the class and preliminarily approved the proposed settlement, including the payment of $55.0 million, of which $10.0 million was agreed to be funded by the Company’s insurers. The settlement was paid into escrow in June 2016, with distribution to the class to occur after the Court had finally approved the settlement and the plan of allocation of those proceeds. On September 8, 2016, the Court granted final approval of the settlement. The final judgment and order of the Court included a dismissal of the action with prejudice against all defendants. The defendants do not admit any liability as part of the settlement.  

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	2 0 . Subsequent Events On January 1, 2017, the numbers of shares reserved for issuance under the 2012 Plan was increased by 993,558 shares, as a result of the automatic increase in shares reserved pursuant to the terms thereof. The Company has evaluated events subsequent to the balance sheet dates and determined there have not been any other events that have occurred that would require adjustment to or disclosure in the consolidated financial statements.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Summary of Significant Accounting Policies [Abstract]
Principles of Consolidation	 Principles of Consolidation The consolidated financial statements include the accounts of Intercept and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company has no unconsolidated subsidiaries or investments accounted for under the equity method.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid securities with a maturity of three months or less at acquisition to be cash equivalents.
Investment Securities, Available for Sale	Investment Securities, Available for Sale Investment securities are considered to be available-for-sale and are carried at fair value. Unrealized gains and losses, if any, are reported in other comprehensive income (loss). The cost of investment securities classified as available-for-sale is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in interest income. Realized gains and losses, and declines in value judged to be other-than-temporary, if any, are also included in other income, net. The cost of securities sold is based on the specific identification method. The estimated fair value of the available for sale securities is determined based on quoted market prices or rates for similar instruments.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments, including cash and cash equivalents, receivables, accounts payable and accrued liabilities are carried at cost which management believes approximates fair value because of the short term maturity of these instruments.
Risks and Uncertainties	Risks and Uncertainties The Company is subject to risks common to companies in the pharmaceutical industry including failing to secure additional funding, uncertainties related to commercialization of products, and regulatory approval.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash, cash equivalents and investment securities. The Company currently invests its excess cash primarily in money market funds, U.S. Treasury notes, and high quality, marketable debt instruments of corporations, financial institutions and government sponsored enterprises. The Company has adopted an investment policy that includes guidelines relative to credit quality, diversification and maturities to preserve principal and liquidity. On a consolidated basis, for the year ended December 31, 2016, the Company’s three largest customers (as discussed in more detail below under “Revenue Recognition”) accounted for 49% , 37% and 12% , of the Company’s gross sales, respectively.
Accounts Receivable	Accounts Receivable The Company extends credit to customers based on its evaluation of the customer’s financial condition. The Company records receivables for all billings when amounts are due under standard terms. Accounts receivable are stated at amounts due net of applicable prompt pay discounts and other contractual adjustments as well as an allowance for doubtful accounts. The Company assesses the need for an allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due, the customer’s ability to pay its obligation and the condition of the general economy and the industry as a whole. The Company will write off accounts receivable when the Company determines that they are uncollectible. The Company has recorded $9.1 million of accounts receivable as of December 31, 2016 and has no t recorded an allowance for any doubtful accounts as of December 31, 2016. On a consolidated basis, the Company’s three largest customers accounted for 45% , 38% and 14% of the December 31, 2016 accounts receivable balance, respectively.
Fixed Assets	Fixed Assets Fixed assets are stated at cost, and depreciated over the estimated useful life of the assets. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, generally three to seven years. Leasehold improvements are amortized over the shorter of the asset’s useful life or the life of the lease term . Expenditures for maintenance and repairs are charged to expense as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist of fixed assets. The Company evaluates long-lived assets for impairment when events and circumstances indicate that the carrying amount of an asset or group of assets may not be fully recoverable.
Inventory	Inventory Inventories are stated at the lower of cost or estimated realizable value. The Company determines the cost of inventory using the first-in, first-out, or FIFO, method. The Company capitalizes inventory costs associated with the Company's product after regulatory approval when, based on management's judgment, future commercialization is considered probable and the future economic benefit is expected to be realized; otherwise, such costs are expensed as research and development. The Company periodically analyzes its inventory levels to identify inventory that may expire prior to expected sale or has a cost basis in excess of its estimated realizable value, and writes-down such inventories as appropriate. In addition, the Company's product is subject to strict quality control and monitoring which the Company performs throughout the manufacturing process. If certain batches or units of product no longer meet quality specifications or become obsolete due to expiration, the Company records a charge to cost of sales sold to write down such unmarketable inventory to zero.
Convertible Senior Notes	Convertible Senior Notes The Company’s 3.25% convertible senior notes due 2023 (the “Convertible Notes”) are accounted for in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification (“ASC”) 470, formerly FSP APB 14-1, Accounting for Convertible Debt Instruments That May be Settled in Cash upon Conversion (Including Partial Cash Settlement). ASC Subtopic 470-20 requires the issuer of convertible debt that may be settled in shares or cash upon conversion at the issuer's option, such as these notes, to account for the liability (debt) and equity (conversion option) components separately. The value assigned to the debt component is the estimated fair value, as of the issuance date, of a similar debt instrument without the conversion option. The amount of the equity component (and resulting debt discount) is calculated by deducting the fair value of the liability component from the principal amount of the convertible debt instrument. The resulting debt discount is amortized as additional non-cash interest expense over the expected life of the notes utilizing the effective interest method. Although ASC 470 has no impact on the Company’s actual past or future cash flows, it requires the Company to record non-cash interest expense as the debt discount is amortized. For additional information, see Note 10 – Long-Term Debt.
Revenue Recognition	Revenue Recognition Product Revenue, Net Revenue is recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence that an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the fee is fixed or determinable; and (4) collectability is reasonably assured. When the revenue recognition criteria are not met, we defer the recognition of revenue by recording deferred revenue on the balance sheet until such time that all criteria are met. Beginning in June 2016, subsequent to the U.S. Food and Drug Administration (“FDA”) approval of Ocaliva ® (obeticholic acid or “OCA”) for the treatment of PBC, the Company sells Ocaliva in the United States principally to a limited number of specialty pharmacies which dispense the product directly to patients. The specialty pharmacies are referred to as the Company’s customers. The Company provides the right of return to its customers for unopened product for a limited time before and after its expiration date. Given the Company’s limited sales history for Ocaliva and the inherent uncertainties in estimating product returns, the Company has determined that the shipments of Ocaliva made to its customers thus far do not meet the criteria for revenue recognition at the time of shipment. Accordingly, the Company recognizes revenue when the product is sold through by its customers, provided all other revenue recognition criteria are met. The Company invoices its customers upon shipment of Ocaliva to them and records accounts receivable, with a corresponding liability for deferred revenue equal to the gross invoice price. The Company then recognizes revenue when Ocaliva is sold through as specialty pharmacies dispense product directly to the patients. The Company recognized net sales of Ocaliva of $18.2 million for the year ended December 31, 2016. The Company also recorded $3.9 million in deferred revenues recorded in short-term portion of deferred revenue on its balance sheet, which represents product shipped to distributors, but not sold through as of December 31, 2016. The Company has written contracts with each of its customers and delivery occurs when the customer receives Ocaliva. The Company evaluates the creditworthiness of each of its customers to determine whether collection is reasonably assured. In order to conclude that the price is fixed and determinable, the Company must be able to (i) calculate its gross product revenues from the sales to its customers and (ii) reasonably estimate its net product revenues. The Company calculates gross product revenues based on the wholesale acquisition cost that the Company charges its customers for Ocaliva. The Company estimates its net product revenues by deducting from its gross product revenues (i) trade allowances, such as invoice discounts for prompt payment and customer fees, (ii) estimated government rebates and discounts related to Medicare, Medicaid and other government programs, and (iii) estimated costs of incentives offered to certain indirect customers including patients. Trade Allowances The Company provides invoice discounts on Ocaliva sales to certain of its customers for prompt payment and records these discounts as a reduction to gross product revenues. These discounts are based on contractual terms. Rebates and Discounts The Company contracts with Centers for Medicare & Medicaid Services (“CMS”) and other government agencies to make Ocaliva available to eligible patients. As a result, the Company estimates any rebates and discounts and deducts these estimated amounts from its gross product revenues at the time the revenues are recognized. The Company’s estimates of rebates and discounts are based on the government mandated discounts, which are statutorily-defined and applicable to these government funded programs. These estimates are recorded in accrued liabilities on the condensed consolidated balance sheet. Other Incentives Other incentives that the Company offers to indirect customers include co-pay assistance cards provided by the Company for PBC patients whom reside in states that permit co-pay assistance programs. The Company’s co-pay assistance program is intended to reduce each participating patient’s portion of the financial responsibility for Ocaliva purchase price to a specified dollar amount. The Company estimates each period the amount of co-pay assistance provided to eligible patients based on the terms of the program when product is dispensed by the specialty pharmacies to the patients. These estimates are based on redemption information provided by third party claims processing organizations and are recorded in accrued liabilities on the condensed consolidated balance sheet.  Licensing Revenue  The Company accounts for the development, regulatory and sales milestones within an arrangement in accordance with the milestone method of revenue recognition. This method allows for the recognition of consideration which is contingent on the achievement of a substantive milestone in its entirety in the period the milestone is achieved. Each future milestone is considered substantive if it (i) relates solely to the past performance of the intellectual property to achieve the milestone; (ii) is reasonable relative to all of the deliverables and payment terms in the arrangement; and (iii) is commensurate with either the Company’s performance or the enhanced value of the intellectual property as a result of a specific outcome resulting from the Company’s performance.
Research and Development	Research and Development Expenses Research and development costs that do not have alternative future use are charged to expense as incurred. This includes the cost of conducting clinical trials, compensation and related overhead for employees and consultants involved in research and development and the cost of the Company’s manufacturing activities to supply ongoing and future clinical trials and preclinical studies as well as preparations for commercialization of obeticholic acid (“OCA”). For periods prior to the commercial launch of Ocaliva in PBC in June 2016, the manufacturing costs for OCA were expensed as part of research and development. The Company will continue to incur manufacturing costs for commercial supply of OCA in other indications such as NASH prior to their approval.
Stock-Based Compensation	Stock-based Compensation The Company accounts for stock-based compensation in accordance with Financial Accounting Standards Board's Accounting Standards Codification ("ASC") 718, "Compensation - Stock Compensation" (ASC 718). The Company estimates the fair value of stock options using the Black-Scholes option pricing model on the date of the grant. Restricted stock units and restricted stock awards are valued based on the closing price of the Company’s common stock on the date of the grant. The fair value of equity instruments expected to vest after taking into consideration an estimate of award forfeitures based on actual experience are recognized and amortized on a straight-line basis over the requisite service period of the award. Generally stock options fully vest four years from the grant date and have a term of ten years. The Company recognizes stock-based compensation for consultants on a mark–to-market basis which is updated on a quarterly basis.
Warrants to Purchase Common Stock	Warrants to Purchase Common Stock In conjunction with various financing transactions, the Company issued warrants to purchase the Company’s common stock. Certain of the warrants included a so-called “down round” provision that provided for a reduction in the warrant exercise price if there were subsequent issuances of additional shares of common stock for consideration per share less than the per share warrant exercise prices and certain warrants contained a provision that required the underlying shares to be registered upon an initial public offering (“IPO”). These warrants were deemed to be derivative instruments and as such, were recorded as a liability and were marked-to-market at each reporting period using the Black-Scholes option pricing model. The Company estimated the fair values of the warrants at each reporting period using a Black-Scholes option-pricing. Management concluded, under the Company’s facts and circumstances, that the estimated fair values of the warrants using the Black-Scholes option-pricing model approximates, in all material respects, the values determined using a binomial valuation model. The estimates in the Black-Scholes option-pricing model and the binomial valuation model are based, in part, on subjective assumptions, including but not limited to stock price volatility, the expected life of the warrants, the risk free interest rate and the fair value of the common stock underlying the warrants. Changes in the fair value of the common stock warrant liability from the prior period were recorded as a component of other income and expense.
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing net income (loss) attributable to common stockholders (numerator) by the weighted average number of common shares outstanding (denominator) during the period. Diluted net income (loss) per share gives effect to all dilutive potential common shares outstanding during the period including stock options, restricted stock units (“RSUs”) and warrants using the treasury stock method.
Income Taxes	Income Taxes The Company utilizes the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement carrying amounts and tax bases of assets and liabilities using enacted tax rates in effect for years in which the temporary differences are expected to reverse. The Company establishes a valuation allowance when it believes it is more likely than not that deferred tax assets will not be realized. The Company determines the need for a valuation allowance by assessing the probability of realizing deferred tax assets, taking into consideration all available positive and negative evidence, including historical operating results, expectations of future taxable income, carryforward periods available, various income tax strategies and other relevant factors. Significant judgment is required in making this assessment and to the extent future expectations change, the Company would have to assess the recoverability of its deferred assets at that time. At December 31, 2016 and 2015, the Company maintained a full valuation allowance on its deferred tax assets. At any one time the Company’s tax returns for numerous tax years are subject to examination by U.S. Federal, state, and foreign taxing jurisdictions. The impact of an uncertain tax position taken or expected to be taken on an income tax return must be recognized in the financial statements at the largest amount that is more likely than not to be sustained. An uncertain income tax position will not be recognized in the financial statements unless it is more likely than not to be sustained. At December 31, 2016 and 2015, the Company had no reserves for unrecognized tax benefits.
Segments	Segments The Company operates in one segment. The Company is a biopharmaceutical company focused on discovering, developing and commercializing treatments for non-viral, progressive liver diseases.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2015, the FASB issued Accounting Standards update (“ASU”) 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes, which requires that deferred tax assets and liabilities, as well as any related valuation allowance, be classified as noncurrent on the balance sheet rather than being separated into current and noncurrent. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2016. Early adoption is permitted and may be applied either retrospectively or on a prospective basis. The Company has early adopted this ASU effective with its annual reporting period ended December 31, 2016 on a prospective basis. The adoption did not have a material impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (“ASU 2016-02”) which supersedes Topic 840, Leases. ASU 2016-02 requires lessees to recognize a right-of-use asset and a lease liability on their balance sheets for all the leases with terms greater than twelve months. Based on certain criteria, leases will be classified as either financing or operating, with classification affecting the pattern of expense recognition in the income statement. For leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients primarily focused on leases that commenced before the effective date of Topic 842, including continuing to account for leases that commence before the effective date in accordance with previous guidance, unless the lease is modified. The Company is evaluating the impact of the adoption of the standard on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, which is intended to improve the accounting for share-based payment transactions as part of the FASB’s simplification initiative. The ASU changes certain aspects of the accounting for share-based payment award transactions, including: (1) accounting for income taxes; (2) classification of excess tax benefits on the statement of cash flows; (3) forfeitures; (4) minimum statutory tax withholding requirements; and (5) classification of employee taxes paid on the statement of cash flows when an employer withholds shares for tax withholding purposes. The ASU is effective for fiscal years beginning after December 15, 2016, and interim periods within those years for public business entities. We do not expect the adoption of this updated standard to have a material impact on our consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements of FASB ASC Topic 605, Revenue Recognition and most industry-specific guidance throughout the ASC, resulting in the creation of FASB ASC Topic 606, Revenue from Contracts with Customers. ASU 2014-09 requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. This ASU provides alternative methods of adoption. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers, Deferral of the Effective Date ("ASU 2015-14"). ASU 2015-14 defers the effective date of ASU 2014-09 by one year to December 15, 2017 for fiscal years, and interim periods within those years, beginning after that date and permits early adoption of the standard, but not before the original effective date for fiscal years beginning after December 15, 2016. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers, Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08") clarifying the implementation guidance on principal versus agent considerations. Specifically, an entity is required to determine whether the nature of a promise is to provide the specified good or service itself (that is, the entity is a principal) or to arrange for the good or service to be provided to the customer by the other party (that is, the entity is an agent). The determination influences the timing and amount of revenue recognition. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing, clarifying the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improves the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). The effective date and transition requirements for ASU 2016-08 and ASU 2016-10 are the same as the effective date and transition requirements for ASU 2014-09. The Company is currently assessing the potential impact of adopting ASU 2014-09, ASU 2016-08 and ASU 2016-10 on its financial statements and related disclosures. On August 27, 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern (“ASU 2014-15”), which requires an entity to evaluate whether conditions or events, in the aggregate, raise substantial doubt about the entity's ability to continue as a going concern for one year from the date the financial statements are issued or are available to be issued. The guidance became effective January 1, 2017. The adoption of ASU 2014-15 is not expected to have an impact on our consolidated financial position, results of operations or cash flows.

Cash, Cash Equivalents, and I29

Cash, Cash Equivalents, and Investments (Tables)	12 Months Ended
	Dec. 31, 2016
Cash, Cash Equivalents, and Investments [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The following table summarizes the Company’s cash, cash equivalents and investments as of December 31, 2016 and December 31, 201 5:     As of December 31, 2016  Gross Gross  Amortized Cost Unrealized Unrealized Fair Value  Gains Losses   (in thousands)  Cash and cash equivalents:  Cash and money market funds $ 43,675 $ - $ - $ 43,675  Investment securities:  Commercial paper 66,185 - (71) 66,114  Corporate debt securities 554,847 14 (1,443) 553,418  U.S. government and agency securities 26,254 - (76) 26,178  Total investments 647,286 14 (1,590) 645,710  Total cash, cash equivalents and investments $ 690,961 $ 14 $ (1,590) $ 689,385     As of December 31, 2015  Gross Gross  Amortized Cost Unrealized Unrealized Fair Value  Gains Losses   (in thousands)  Cash and cash equivalents:  Cash and money market funds $ 32,742 $ - $ - $ 32,742  Investment securities:  Commercial paper 1,993 - (3) 1,990  Corporate debt securities 529,368 2 (1,720) 527,650  U.S. government and agency securities 65,854 1 (182) 65,673  Total investments 597,215 3 (1,905) 595,313  Total cash, cash equivalents and investments $ 629,957 $ 3 $ (1,905) $ 628,055 
Available-for-sale Securities	The estimated fair value of marketable debt securities (commercial paper, corporate debt securities, U.S. government and agency securities, and municipal securities) as of December 31, 2016 and 2015, respectively, by contractual maturity, are as follows:      Fair Value as of December 31,  2016 2015  (in thousands)  Due in one year or less $ 456,184 $ 343,758  Due after one year through 2 years 189,526 251,555  Total investments in debt securities $ 645,710 $ 595,313 
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	The Company held a total of two positions as of December 31, 2016 and no positions as of December 31, 2015 that were in a n unrealized loss position for more than twelve months.  The fair value for the Company’s available-for-sale investments, which have been in an unrealized loss position for less than and longer than 12 months is as follows :        As of December 31, 2016  Less than 12 months 12 Months or greater Total  (in thousands)  Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses  Corporate debt securities $ 341,823 $ (510) $ 178,818 $ (933) $ 520,641 $ (1,443)  U.S. government and agency securities 19,479 (30) 6,699 (46) 26,178 (76)  Commercial paper 66,114 (71) - - 66,114 (71)  Total $ 427,416 $ (611) $ 185,517 $ (979) $ 612,933 $ (1,590)    As of December 31, 2015  Less than 12 months 12 Months or greater Total  (in thousands)  Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses  Corporate debt securities $ 316,036 $ (551) $ 201,676 $ (1,169) $ 517,712 $ (1,720)  Commercial paper 15,793 (30) 44,879 (152) 60,672 (182)  U.S. government and agency securities 1,990 (3) - - 1,990 (3)  Total $ 333,819 $ (584) $ 246,555 $ (1,321) $ 580,374 $ (1,905) 

Prepaid Expenses and Other Cu30

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Prepaid Expenses and Other Current Assets [Abstract]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure	Prepaid expenses and other current assets consisted of the following:       December 31,  2016 2015  (in thousands)  Prepaid expenses and other receivables $ 6,145 $ 9,947  Interest receivable 3,209 3,304  Contract receivable - 47  Refundable tax credits - 340  Prepaid expenses and other current assets $ 9,354 $ 13,638 

Fixed Assets, Net (Tables)

Fixed Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2016
Fixed Assets, Net [Abstract]
Property, Plant and Equipment	Fixed assets are stated at cost and depreciated or amortized using the straight-line method based on useful lives as follows:       Useful lives December 31,  (Years) 2016 2015  (in thousands)  Office equipment and software 3 $ 4,942 $ 2,188  Leasehold improvements Over life of lease 6,668 6,818  Furniture and fixtures 7 4,202 3,402  Subtotal 15,812 12,408  Less: accumulated depreciation (4,517) (2,361)  Fixed assets, net $ 11,295 $ 10,047

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2016
Inventory [Abstract]
Schedule of Inventory	Inventories are stated at the lower of cost or market. Inventories consist of the following:     December 31,  2016 2015  (in thousands)  Work-in-process $ 2,207 $ -  Finished goods 72 -  Inventory, net $ 2,279 $ - 

Accounts Payable, Accrued Exp33

Accounts Payable, Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Accounts Payable, Accrued Expenses and Other Liabilities [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable, accrued expenses and other liabilities consisted of the following:       December 31,  2016 2015  (in thousands)  Accounts payable $ 6,722 $ 4,170  Accrued employee compensation 19,287 11,414  Accrued contracted services and other 39,542 30,007  Accounts payable, accrued expenses and other liabilities $ 65,551 $ 45,591 

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Long-Term Debt [Abstract]
Schedule of Long-term Debt Instruments	Debt, net of discounts and deferred financing costs, consists of the following:      December 31,  2016 2015  (in thousands)  Long-term debt $ 341,356 $ -  Less current portion - -  Long-term debt outstanding $ 341,356 $ - 

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Measurements [Abstract]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis	Financial assets carried at fair value are classified in the tables below in one of the three categories described above:      Fair Value Measurements Using  Total Level 1 Level 2 Level 3  (in thousands)  December 31, 2016  Assets:  Money market funds $ 11,755 $ 11,755 $ - $ -  Available for sale securities:  Commercial paper 66,114 - 66,114 -  Corporate debt securities 553,418 - 553,418 -  U.S. government and agency securities 26,178 - 26,178 -  Total financial assets: $ 657,465 $ 11,755 $ 645,710 $ -   December 31, 2015  Assets:  Money market funds $ 4,826 $ 4,826 $ - $ -  Available for sale securities:  Commercial paper 1,990 - 1,990 -  Corporate debt securities 527,650 - 527,650 -  U.S. government and agency securities 65,673 - 65,673 -  Total financial assets: $ 600,139 $ 4,826 $ 595,313 $ - 
Schedule of Available for Sale Securities Debt Maturities	The estimated fair value of marketable debt securities (commercial paper, corporate debt securities, U.S. government and agency securities, and municipal securities) as of December 31, 2016 and 2015, respectively, by contractual maturity, are as follows:      Fair Value as of December 31,  2016 2015  (in thousands)  Due in one year or less $ 456,184 $ 343,758  Due after one year through 2 years 189,526 251,555  Total investments in debt securities $ 645,710 $ 595,313 

Stock Compensation (Tables)

Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Stock Compensation [Abstract]
Schedule of Share Based Compensation Arrangement By Share Based Payment Award Grants in Period Fair Value Assumptions	The Company estimated the fair value of stock options granted in the periods presented using a Black-Scholes option-pricing model utilizing the following assumptions:       Years Ended December 31,  2016 2015 2014  Volatility 60 - 66% 61 - 90% 70 - 150%  Expected term (in years) 5.1 - 10.0 5.1 - 7.0 4.0 - 7.0  Risk-free rate 1.1 - 2.4% 0.2 - 2.2% 1.3 - 2.7%  Expected dividend yield — % — % — % 
Schedule of Share Based Compensation Stock Options Activities	The Company’s combined outstanding employee and non-employee option activity for the period from December 31, 2015 through December 31, 2016 is summarized as follows:     Weighted  Average  Number Weighted Remaining Aggregate  of Shares Average Contractual Intrinsic Value  (in thousands) Exercise Price Term (years) (in thousands)  Outstanding at December 31, 2015 1,348 $ 108.49 7.3 $ 91,402  Granted 481 $ 112.82 6.1 $ -  Exercised (185) $ 28.07 - $ 21,987  Cancelled/forfeited (81) $ 129.91 - $ -  Expired (10) $ 177.02 - $ -  Outstanding at December 31, 2016 1,553 $ 117.80 7.4 $ 48,308  Expected to vest 1,531 $ 117.40 7.3 $ 48,199  Exercisable 797 $ 90.73 6.1 $ 43,156 
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	The following table summarizes the aggregate activities in relation to RSU and RSA activity for the years ended December 31, 2016 and 2015 :    Number of Shares (in thousands) Weighted Average Grant Date Fair Value  Non-vested Shares at December 31, 2015 193 $ 183.19  Granted 312 $ 117.63  Exercised (92) $ 161.03  Cancelled/forfeited (32) $ 159.22  Non-vested Shares at December 31, 2016 381 $ 136.89 
Schedule of Stock Based Compensation Expense	Stock-based compensation expense has been reported in our statements of operations as follows:     Years Ended December 31,  2016 2015 2014  (in thousands)   Selling, general and administrative $ 32,073 $ 16,223 $ 8,418  Research and development 14,132 17,966 11,709  Total stock-based compensation $ 46,205 $ 34,189 $ 20,127 

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Taxes [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The components of loss before income taxes for the years ended December 31, 2016, 2015 and 2014 includes the following:    Years Ended December 31,  2016 2015 2014  (in thousands)  United States $ (154,812) $ (116,349) $ (283,226)  Foreign (258,018) (110,080) -  Total $ (412,830) $ (226,429) $ (283,226) 
Schedule of Components of Income Tax Expense (Benefit)	Income tax expense (benefit) differed from the amounts computed by applying the U.S. Federal income tax rate of 34% to loss before income taxes as a result of the following:     Years Ended December 31,  2016 2015 2014  (in thousands)  Computed "expected" tax benefit $ (140,362) $ (76,986) $ (96,297)  State taxes, net of U.S. Federal benefit - - -  U.S. Federal valuation allowance 40,377 40,973 36,052  Stock-based compensation 5,161 (3,230) 342  Officer compensation 50 (1,778) 1,784  Foreign tax rate differences 94,901 37,427 -  Intercompany license of intellectual property - 3,400 -  Mark to market warrant income - - 58,083  Other (127) 194 36  Total $ - $ - $ - 
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to the deferred tax assets and liabilities at December 31, 2016 and 2015 are presented below:     December 31,  2016 2015  (in thousands)  Deferred tax assets:  Net operating loss and other carryforwards $ 220,175 $ 127,364  Stock compensation 17,166 9,929  Deferred revenue 2,400 2,846  Accrued compensation 4,775 3,058  Accrued expense 1,841 1,447  Intellectual property 3,570 1,775  Other 759 802  Deferred tax assets before valuation allowance 250,686 147,221  Valuation allowance (223,383) (147,221)  Total deferred tax assets 27,303 -  Deferred tax liabilities:  Convertible Note (27,303) -  Total deferred tax liabilities (27,303) -  Net deferred tax asset (liability) $ - $ - 

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	As of December 31, 2016, minimum operating lease payments under non-cancelable leases, as amended, are as follows:     Year Ending December 31, Amount  (in thousands)  2017 $ 9,191  2018 9,383  2019 16,159  2020 15,331  2021 12,746  Thereafter 107,076  Total future minimum operating lease payments $ 169,886 

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Net Loss Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	The following table presents the historical computation of basic and diluted net loss per share:       Years Ended December 31,  2016 2015 2014  (in thousands, except per share amounts)  Historical Net loss per share  Numerator:  Net loss attributable to common stockholders $ (412,830) $ (226,429) $ (283,226)  Denominator:  Weighted average shares outstanding, basic and diluted 24,663 23,694 20,784  Net loss per share, basic and diluted $ (16.74) $ (9.56) $ (13.63) 
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following potentially dilutive securities have been excluded from the computations of diluted weighted average shares outstanding as of December 31, 2016, 2015 and 2014, as they would have been anti-dilutive:       December 31,  2016 2015 2014  (in thousands)  Options 1,553 1,348 1,436  Restricted stock units 382 193 119  Total 1,935 1,541 1,555 

Quarterly Financial Data (una40

Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table summarizes the unaudited quarterly financial data for the years ended December 31, 2016 and 2015;        Quarters Ended  March 31, June 30, September 30, December 31, Total  2016 (in thousands, except for per share amounts)  Revenues $ 445 $ 5,520 $ 5,177 $ 13,809 $ 24,951  Operating loss (127,400) (78,095) (83,036) (114,007) (402,538)  Net loss (126,674) (77,299) (88,815) (120,042) (412,830)  Net loss per common share - basic and diluted $ (5.17) $ (3.14) $ (3.59) $ (4.84)   2015  Revenues $ 1,447 $ 445 $ 445 $ 445 $ 2,782  Operating loss (39,658) (48,824) (51,784) (88,890) (229,156)  Net loss (39,386) (47,894) (50,896) (88,253) (226,429)  Net loss per common share - basic and diluted $ (1.78) $ (1.99) $ (2.10) $ (3.62) 

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Summary of Significant Accounting Policies [Abstract]
Amount reclassifed from research and development expense to selling, general and administrative expense	$ 15.5

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)segment	Dec. 31, 2015USD ($)
Accounts receivable	$ 9,126
Allowance for doubtful accounts receivable, current	$ 0
Property, plant and equipment, depreciation methods	straight-line method
Fair value assumption method used	Black-Scholes option-pricing
Product revenue, net	$ 18,169
Deferred revenue, current	$ 5,694	$ 1,782
Vesting period	4 years
Expected term (in years)	10 years
Number of operating segments | segment	1
Product Shipped But Not Sold [Member]
Deferred revenue, current	$ 3,900
Accounts Receivable [Member] | Customer Concentration Risk One [Member]
Concentration risk, percentage	45.00%
Accounts Receivable [Member] | Customer Concentration Risk Two [Member]
Concentration risk, percentage	38.00%
Accounts Receivable [Member] | Customer Concentration Risk Three [Member]
Concentration risk, percentage	14.00%
Sales Gross [Member] | Customer Concentration Risk One [Member]
Concentration risk, percentage	49.00%
Sales Gross [Member] | Customer Concentration Risk Two [Member]
Concentration risk, percentage	37.00%
Sales Gross [Member] | Customer Concentration Risk Three [Member]
Concentration risk, percentage	12.00%
Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life	7 years	7 years
Leasehold Improvements [Member]
Property, plant and equipment, depreciation methods	amortized over the shorter of the asset's useful life or the life of the lease term
Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life	7 years

Significant Agreements (Narrati

Significant Agreements (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	May 31, 2014	Mar. 31, 2011	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Licensing revenue			$ 6,782	$ 2,782	$ 1,742
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Development milestone reached			$ 6,000
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member] | Criteria One [Member]
Contingent arrangement receivable amount		$ 5,000
License arrangement, milestone benchmark		50,000
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member] | Criteria Two [Member]
Contingent arrangement receivable amount		10,000
License arrangement, milestone benchmark		100,000
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member] | Criteria Three [Member]
Contingent arrangement receivable amount		20,000
License arrangement, milestone benchmark		200,000
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member] | Criteria Four [Member]
Contingent arrangement receivable amount		40,000
License arrangement, milestone benchmark		400,000
Nonsoftware License Arrangement [Member] | Sumitomo Dainippon Pharma Co Ltd [Member] | Criteria Five [Member]
Contingent arrangement receivable amount		120,000
License arrangement, milestone benchmark		1,200,000
Nonsoftware License Arrangement [Member] | Up-front Payment [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
License agreement payment		15,000
Nonsoftware License Arrangement [Member] | Additional Development Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		30,000
Nonsoftware License Arrangement [Member] | Additional Regulatory Approval Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		70,000
Nonsoftware License Arrangement [Member] | Additional Sales Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		200,000
Japan [Member] | Nonsoftware License Arrangement [Member] | Additional Regulatory Approval Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		15,000
China [Member] | Nonsoftware License Arrangement [Member] | Additional Regulatory Approval Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		10,000
United States [Member] | Nonsoftware License Arrangement [Member] | Additional Regulatory Approval Receivable [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
Contingent arrangement receivable amount		$ 5,000
Korea [Member] | Nonsoftware License Arrangement [Member] | Up-front Payment [Member] | Sumitomo Dainippon Pharma Co Ltd [Member]
License agreement payment	$ 1,000,000

Cash, Cash Equivalents, and I44

Cash, Cash Equivalents, and Investments (Schedule of Available-for-sale Securities Reconciliation) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments:
Total investments, Amortized Cost	$ 647,286	$ 597,215
Total cash and cash equivalents and investments, Amortized Cost	690,961	629,957
Total investments, Gross Unrealized Gains	14	3
Total cash and cash equivalents and investments, Gross Unrealized Gains	14	3
Total investments, Gross Unrealized Losses	(1,590)	(1,905)
Total cash and cash equivalents and investments, Gross Unrealized Losses	(1,590)	(1,905)
Total investments, Fair Value	645,710	595,313
Total cash and cash equivalents and investments, Fair Value	689,385	628,055
Commercial Paper [Member]
Investments:
Total investments, Amortized Cost	66,185	1,993
Total investments, Gross Unrealized Losses	(71)	(3)
Total investments, Fair Value	66,114	1,990
Corporate Debt Securities [Member]
Investments:
Total investments, Amortized Cost	554,847	529,368
Total investments, Gross Unrealized Gains	14	2
Total investments, Gross Unrealized Losses	(1,443)	(1,720)
Total investments, Fair Value	553,418	527,650
US Government Agencies Debt Securities [Member]
Investments:
Total investments, Amortized Cost	26,254	65,854
Total investments, Gross Unrealized Gains		1
Total investments, Gross Unrealized Losses	(76)	(182)
Total investments, Fair Value	26,178	65,673
Cash and Money Market Funds [Member]
Cash and cash equivalents:
Cash and Cash Equivalents, Amortized Cost	43,675	32,742
Cash and cash equivalents, Fair Value	$ 43,675	$ 32,742

Cash, Cash Equivalents, and I45

Cash, Cash Equivalents, and Investments (Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Total available for sale securities, Less than 12 months, Fair Value	$ 427,416	$ 333,819
Total available for sale securities Less than 12 months, Gross Unrealized Holding Losses	(611)	(584)
Total available for sale securities, More than 12 months, Fair Value	185,517	246,555
Total available for sale securities more than 12 months, Gross Unrealized Holding Losses	(979)	(1,321)
Available-for-sale securities, Total Fair Value	612,933	580,374
Available-for-sale securities, Total Gross Unrealized Losses	(1,590)	(1,905)
Corporate Debt Securities [Member]
Total available for sale securities, Less than 12 months, Fair Value	341,823	316,036
Total available for sale securities Less than 12 months, Gross Unrealized Holding Losses	(510)	(551)
Total available for sale securities, More than 12 months, Fair Value	178,818	201,676
Total available for sale securities more than 12 months, Gross Unrealized Holding Losses	(933)	(1,169)
Available-for-sale securities, Total Fair Value	520,641	517,712
Available-for-sale securities, Total Gross Unrealized Losses	(1,443)	(1,720)
Commercial Paper [Member]
Total available for sale securities, Less than 12 months, Fair Value	66,114	15,793
Total available for sale securities Less than 12 months, Gross Unrealized Holding Losses	(71)	(30)
Total available for sale securities, More than 12 months, Fair Value		44,879
Total available for sale securities more than 12 months, Gross Unrealized Holding Losses		(152)
Available-for-sale securities, Total Fair Value	66,114	60,672
Available-for-sale securities, Total Gross Unrealized Losses	(71)	(182)
US Government Agencies Debt Securities [Member]
Total available for sale securities, Less than 12 months, Fair Value	19,479	1,990
Total available for sale securities Less than 12 months, Gross Unrealized Holding Losses	(30)	(3)
Total available for sale securities, More than 12 months, Fair Value	6,699
Total available for sale securities more than 12 months, Gross Unrealized Holding Losses	(46)
Available-for-sale securities, Total Fair Value	26,178	1,990
Available-for-sale securities, Total Gross Unrealized Losses	$ (76)	$ (3)

Prepaid Expenses and Other Cu46

Prepaid Expenses and Other Current Assets (Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid expenses and other receivables	$ 6,145	$ 9,947
Interest receivable	3,209	3,304
Contract receivable		47
Refundable tax credits		340
Prepaid expenses and other current assets	$ 9,354	$ 13,638

Fixed Assets, Net (Narrative) (

Fixed Assets, Net (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fixed Assets, Net [Abstract]
Depreciation	$ 3,831	$ 1,691	$ 443

Fixed Assets, Net (Fixed Assets

Fixed Assets, Net (Fixed Assets Stated at Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fixed assets	$ 15,812	$ 12,408
Less: accumulated depreciation	(4,517)	(2,361)
Property, Plant and Equipment, Net, Total	11,295	10,047
Office Equipment [Member]
Fixed assets	$ 4,942	$ 2,188
Property, Plant and Equipment, Useful Life	3 years	3 years
Leasehold Improvements [Member]
Fixed assets	$ 6,668	$ 6,818
Property, Plant and Equipment, Estimated Useful Lives	Over life of lease
Furniture and Fixtures [Member]
Fixed assets	$ 4,202	$ 3,402
Property, Plant and Equipment, Useful Life	7 years	7 years

Inventory (Schedule of Inventor

Inventory (Schedule of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Inventory [Abstract]
Work-in-process	$ 2,207
Finished goods	72
Inventory, net	$ 2,279

Accounts Payable, Accrued Exp50

Accounts Payable, Accrued Expenses and Other Liabilities (Schedule of Accounts Payable and Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable, Accrued Expenses and Other Liabilities [Abstract]
Accounts payable	$ 6,722	$ 4,170
Accrued employee compensation	19,287	11,414
Accrued contracted services and other	39,542	30,007
Accounts payable, accrued expenses and other liabilities	$ 65,551	$ 45,591

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details)	Jul. 06, 2016USD ($)$ / shares	Dec. 31, 2016USD ($)
Proceeds from convertible debt		$ 447,573,000
Payments for capped call transactions and associated costs		38,364,000
Long-term debt		341,356,000
Interest expense		14,196,000
Convertible Senior Notes 3.25% [Member] | Convertible Debt [Member]
Debt instrument, face amount	$ 460,000,000
Proceeds from convertible debt	447,600,000
Debt issuance costs	$ 12,400,000	$ 11,700,000
Debt instrument, convertible, terms of conversion feature		The Convertible Notes are senior unsecured obligations of the Company. Interest is payable semi-annually on January 1 and July 1 of each year, beginning on January 1, 2017. The Convertible Notes mature on July 1, 2023, unless earlier repurchased, redeemed or converted. The Convertible Notes are convertible at the option of holders, under certain circumstances and during certain periods, into cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock, at the Company's election. The initial conversion rate of the Convertible Notes is 5.0358 shares of the Company's common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of approximately $198.58 per share of the Company's common stock. The conversion rate is subject to adjustment upon the occurrence of certain events. The Company may redeem for cash all or part of the Convertible Notes, at its option, on or after July 6, 2021, under certain circumstances at a redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.
Debt instrument, convertible, conversion ratio	5.0358
Debt instrument, convertible, type of equity security		common stock
Debt instrument, convertible, conversion price | $ / shares	$ 198.58
Debt instrument, convertible, earliest date		Jul. 6, 2021
Debt instrument, redemption price, percentage	100.00%
Cap price of capped call transaction | $ / shares	$ 262.2725
Debt instrument liability component effective interest rate	8.40%
Long-term debt	$ 334,400,000	$ 460,000,000
Debt instrument, unamortized discount, noncurrent	$ 113,100,000
Interest expense		14,200,000
Interest payable, current		$ 7,300,000

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-term Debt Instruments) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Long-Term Debt [Abstract]
Long-term Debt, Total	$ 341,356
Long-term debt outstanding	$ 341,356

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value, Marketable Securities Measured on Recurring and Nonrecurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-For-Sale Securities, Fair Value Disclosure	$ 645,710	$ 595,313
Total financial assets	657,465	600,139
Money Market Funds [Member]
Cash and cash equivalents, fair value disclosure	11,755	4,826
Commercial Paper [Member]
Available-For-Sale Securities, Fair Value Disclosure	66,114	1,990
Corporate Debt Securities [Member]
Available-For-Sale Securities, Fair Value Disclosure	553,418	527,650
US Government Agencies Debt Securities [Member]
Available-For-Sale Securities, Fair Value Disclosure	26,178	65,673
Fair Value, Inputs, Level 1 [Member]
Total financial assets	11,755	4,826
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and cash equivalents, fair value disclosure	11,755	4,826
Fair Value, Inputs, Level 2 [Member]
Total financial assets	645,710	595,313
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Available-For-Sale Securities, Fair Value Disclosure	66,114	1,990
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Available-For-Sale Securities, Fair Value Disclosure	553,418	527,650
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Available-For-Sale Securities, Fair Value Disclosure	$ 26,178	$ 65,673

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Available For Sale Securities and Debt Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value Measurements [Abstract]
Due in one year or less	$ 456,184	$ 343,758
Due after 1 year through 2 years	189,526	251,555
Total investments in debt securities	$ 645,710	$ 595,313

Stockholders' Equity and Pref55

Stockholders' Equity and Preferred Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Apr. 30, 2015	Feb. 28, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Stockholders' Equity and Preferred Stock [Abstract]
Common stock, authorized			35,000,000		45,000,000
Common stock, par value (in dollars per share)			$ 0.001		$ 0.001
Stock issued during period, shares, new issues	1,330,865	1,150,000
Shares issued, price per share		$ 176
Proceeds from issuance of common stock	$ 367,100	$ 191,700	$ 558,756	$ 183,475
Preferred stock, authorized			5,000,000		5,000,000
Preferred stock, par value (in dollars per share)			$ 0.001		$ 0.001
Preferred stock, shares issued			0		0

Stock Compensation (Narrative)

Stock Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2017	Oct. 31, 2016	Nov. 30, 2014	Apr. 30, 2014	Oct. 31, 2012	Dec. 31, 2016	Dec. 31, 2015
Fair value assumption method used						Black-Scholes option-pricing
Granted - Number of Shares						481,000
Weighted-average grant date fair value						$ 64.80
Exercised - Aggregate Intrinsic Value						$ 21,987
2003 Stock Incentive Plan [Member]
Fair value assumption method used						Black-Scholes option-pricing model
2012 Stock Plan [Member]
Additional shares available	993,558				555,843	976,101	856,609
Fair value assumption method used						Black-Scholes option-pricing model
Shares available for grant						1,500,000	1,200,000
Stock Options [Member]
Share-based compensation not yet recognized						$ 38,900
Share-based compensation not yet recognized, period						2 years 8 months 19 days
Vested - aggregate fair value						$ 18,200
Restricted Stock [Member]
Granted - Number of Shares		11,725
Share-based compensation not yet recognized, other than options						$ 41,600
Share-based compensation not yet recognized, period						2 years 5 months 19 days
Performance Shares [Member] | Employees and Directors [Member]
Stock issued during period, shares, share-based compensation, gross			10,839	57,063

Stock Compensation (Schedule of

Stock Compensation (Schedule of Share Based Compensation Arrangement By Share Based Payment Award Grants in Period Fair Value Assumptions) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value assumption method used	Black-Scholes option-pricing
Expected term (in years)	10 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	60.00%	61.00%	70.00%
Volatility, maximum	66.00%	90.00%	150.00%
Risk-free interest rate, minimum	1.10%	0.20%	1.30%
Risk-free interest rate, maximum	2.40%	2.20%	2.70%
Expected dividend yield
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 1 month 6 days	5 years 1 month 6 days	4 years
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	10 years	7 years	7 years

Stock Compensation (Schedule 58

Stock Compensation (Schedule of Share Based Compensation Stock Options Activities) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Stock Compensation [Abstract]
Beginning Outstanding, Number of Shares	1,348	1,436
Granted - Number of Shares	481
Exercised - Number of Shares	(185)
Forfeited - Number of Shares	(81)
Expired - Number of Shares	(10)
Ending Outstanding, Number of Shares	1,553	1,348
Expected to vest - Number of shares	1,531
Exercisable - Number of Shares	797
Beginning Outstanding, Weighted Average Exercise Price	$ 108.49
Granted - Weighted Average Exercise Price	112.82
Exercised - Weighted Average Exercise Price	28.07
Forfeited - Weighted Average Exercise Price	129.91
Expired - Weighted Average Exercise Price	177.02
Ending Outstanding, Weighted Average Exercise Price	117.80	$ 108.49
Expected to vest - Weighted Average Exercise Price	117.40
Exercisable - Weighted Average Exercise Price	$ 90.73
Expected to vest - Weighted Average Remaining Term	7 years 3 months 18 days
Exercisable - Weighted Average Remaining Term	6 years 1 month 6 days
Options Outstanding - Aggregate Intrinsic Value	$ 48,308	$ 91,402
Exercised - Aggregate Intrinsic Value	21,987
Expected to vest - Aggregate Intrinsic Value	48,199
Exercisable - Aggregate Intrinsic Value	$ 43,156
Granted - Weighted Average Remaining Term	6 years 1 month 6 days
Options Outstanding - Weighted Average Remaining Life	7 years 4 months 24 days	7 years 3 months 18 days

Stock Compensation (Schedule 59

Stock Compensation (Schedule of Share-based Compensation, Restricted Stock Units and Award Activity) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Stock Compensation [Abstract]
Outstanding, December 31, 2015 | shares	193
Granted - Shares | shares	312
Exercised - Shares | shares	(92)
Forfeited - Shares | shares	(32)
Outstanding, September 30, 2016 | shares	381
Outstanding - Weighted Average Grant Date Fair Value, December 31, 2015 | $ / shares	$ 183.19
Granted - Weighted Average Grant Date Fair Value | $ / shares	117.63
Exercised - Weighted Average Exercise Price | $ / shares	161.03
Forfeited - Weighted Average Grant Date Fair Value | $ / shares	159.22
Outstanding - Weighted Average Grant Date Fair Value, September 30, 2016 | $ / shares	$ 136.89

Stock Compensation (Schedule 60

Stock Compensation (Schedule of Stock Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allocated stock-based compensation	$ 46,205	$ 34,189	$ 20,127
Selling, General and Administrative Expenses [Member]
Allocated stock-based compensation	32,073	16,223	8,418
Research and Development Expense [Member]
Allocated stock-based compensation	$ 14,132	$ 17,966	$ 11,709

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Operating Loss Carryforwards	$ 562.3	$ 454.4
Adjustments to additional paid in capital, income tax benefit from Share-based Compensation	167.9	$ 151
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 76.2
Effective income tax rate reconciliation, at Federal statutory income tax rate, percent	34.00%	34.00%	34.00%
Domestic Tax Authority [Member]
Valuation Allowance [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 40.4
Foreign Tax Authority [Member]
Valuation Allowance [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	57.8
State and Local Jurisdiction [Member]
Valuation Allowance [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 7
Minimum [Member]
Valuation Allowance [Line Items]
Operating Loss Carryforwards, Expiration Dates	Jan. 1, 2024
Maximum [Member]
Valuation Allowance [Line Items]
Operating Loss Carryforwards, Expiration Dates	Dec. 31, 2036
Convertible Debt [Member] | Convertible Senior Notes 3.25% [Member]
Valuation Allowance [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ (29)

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income before Income Tax, Domestic and Foreign) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
United States	$ (154,812)	$ (116,349)	$ (283,226)
Foreign	(258,018)	(110,080)
Components of loss before taxes	$ (412,830)	$ (226,429)	$ (283,226)

Income Taxes (Schedule of Compo

Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
Computed "expected" tax benefit	$ (140,362)	$ (76,986)	$ (96,297)
Change in the valuation allowance	40,377	40,973	36,052
Equity based compensation expense	5,161	(3,230)	342
Officer compensation	50	(1,778)	1,784
Foreign tax rate differences	94,901	37,427
Intercompany license of intellectual property		3,400
Mark to market warrant income			58,083
Other	(127)	194	36
Income Tax Expense (Benefit), Total

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss and other carryforwards	$ 220,175	$ 127,364
Stock compensation	17,166	9,929
Deferred revenue	2,400	2,846
Accrued compensation	4,775	3,058
Accrued expenses	1,841	1,447
Intellectual property	3,570	1,775
Other	759	802
Total deferred tax assets	250,686	147,221
Less valuation allowance	(223,383)	(147,221)
Deferred Tax Assets, Net of Valuation Allowance, Total	27,303
Deferred tax liabilities:
Convertible Note	(27,303)
Deferred tax liabilities	(27,303)
Deferred Tax Assets, Net, Total

Commitments (Narrative) (Detail

Commitments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 07, 2016USD ($)ft²	Feb. 29, 2016USD ($)ft²	Jan. 31, 2016GBP (£)ft²	Jan. 31, 2016USD ($)ft²	May 31, 2014USD ($)ft²
Rent expense	$ 9,191,000
2018 rent expense	12,746,000
Security deposit	17,814,000	$ 4,018,000
Operating leases, rent expense	5,500,000	$ 3,800,000	$ 1,700,000
Purchase obligation	$ 11,900,000
10 Building [Member]
Area of real estate property | ft²				49,000
37th Floor [Member]
Rent expense				$ 5,200,000
40th Floor [Member]
Rent expense				$ 3,500,000
55 Building [Member]
Area of real estate property | ft²				85,000
Rent expense				$ 7,900,000
55 Building 5th Anniversay [Member]
Rent expense				8,700,000
55 Building 10th Anniversay [Member]
Rent expense				$ 9,600,000
New York [Member]
Area of real estate property | ft²					10,785
Rent expense					$ 1,000,000
California [Member]
Area of real estate property | ft²								47,000
Rent expense								$ 875,000
Incentive from Lessor								$ 2,400,000
United Kingdom [Member]
Area of real estate property | ft²						8,549	8,549
Rent expense						£ 726,665	$ 1,000,000

Commitments (Schedule of Future

Commitments (Schedule of Future Minimum Rental Payments for Operating Leases) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Commitments [Abstract]
2,017	$ 9,191
2,018	9,383
2,019	16,159
2,020	15,331
2,021	12,746
Thereafter	107,076
Total future minimum operating lease payments	$ 169,886

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($)	1 Months Ended			12 Months Ended
	Apr. 30, 2015	Feb. 28, 2015	Apr. 30, 2014	Dec. 31, 2015	Dec. 31, 2014
Stock issued during period, shares, new issues	1,330,865	1,150,000
Shares issued, price per share		$ 176
Proceeds from issuance of common stock	$ 367,100,000	$ 191,700,000		$ 558,756,000	$ 183,475,000
Selling Stockholders [Member]
Related party transaction, reimbursable expense			$ 70,000

Net Loss Per Share (Schedule of

Net Loss Per Share (Schedule of Calculation of Numerator and Denominator in Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net income (loss) attributable to common stockholders									$ (412,830)	$ (226,429)	$ (283,226)
Denominator:
Weighted average shares outstanding, basic and diluted (in shares)									24,663	23,694	20,784
Net loss per share, basic and diluted (in dollars per share)	$ (4.84)	$ (3.59)	$ (3.14)	$ (5.17)	$ (3.62)	$ (2.10)	$ (1.99)	$ (1.78)	$ (16.74)	$ (9.56)	$ (13.63)

Net Loss Per Share (Schedule 69

Net Loss Per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details) - shares shares in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Loss Per Share [Abstract]
Options	1,553	1,348	1,436
Restricted stock units	382	193	119
Total	1,935	1,541	1,555

Quarterly Financial Data (Sched

Quarterly Financial Data (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 13,809	$ 5,177	$ 5,520	$ 445	$ 445	$ 445	$ 445	$ 1,447	$ 24,951	$ 2,782	$ 1,742
Operating loss	(114,007)	(83,036)	(78,095)	(127,400)	(88,890)	(51,784)	(48,824)	(39,658)	(402,538)	(229,156)	(113,170)
Net loss	$ (120,042)	$ (88,815)	$ (77,299)	$ (126,674)	$ (88,253)	$ (50,896)	$ (47,894)	$ (39,386)	$ (412,830)	$ (226,429)	$ (283,226)
Net loss per common share-basic and diluted (in dollars per share)	$ (4.84)	$ (3.59)	$ (3.14)	$ (5.17)	$ (3.62)	$ (2.10)	$ (1.99)	$ (1.78)	$ (16.74)	$ (9.56)	$ (13.63)

Litigation (Narrative) (Details

Litigation (Narrative) (Details) - USD ($) $ in Millions	May 23, 2016	Dec. 31, 2016
Loss contingency, domicile of litigation		United States District Court for the Southern District of New York
Litigation settlement, amount	$ 55
Litigation settlement amount via insurance	$ 10
Scot H. Atwood vs. Intercept Pharmaceuticals Incorporated [Member]
Loss contingency, lawsuit filing date		February 21, 2014
Loss contingency, name of plaintiff		Scot H. Atwood
Loss contingency, name of defendant		Intercept Pharmaceuticals, Inc.
George Burton vs. Intercept Pharmaceuticals Incorporated [Member]
Loss contingency, lawsuit filing date		February 28, 2014
Loss contingency, name of plaintiff		George Burton
Loss contingency, name of defendant		Intercept Pharmaceuticals, Inc.

Subsequent Events (Details)

Subsequent Events (Details) - shares	Jan. 01, 2017	Oct. 31, 2012	Dec. 31, 2016	Dec. 31, 2015
2012 Stock Plan [Member]
Additional shares available	993,558	555,843	976,101	856,609