Avadel Pharmaceuticals (AVDL) 10-K 16 Mar 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 09, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Avadel Pharmaceuticals PLC
Entity Central Index Key	1,012,477
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	AVDL
Entity Common Stock, Shares Outstanding		37,952,119
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,017
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 434,848,871

Consolidated Statements of Inco

Consolidated Statements of Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Product sales and services	$ 172,841	$ 147,222	$ 172,288
License and research revenue	404	3,024	721
Total revenue	173,245	150,246	173,009
Operating expenses:
Cost of products and services sold	16,301	13,248	11,410
Research and development expenses	33,418	34,611	25,608
Selling, general and administrative expenses	58,860	44,179	21,712
Intangible asset amortization	3,659	13,888	12,564
(Gain) loss - changes in fair value of related party contingent consideration	(31,040)	49,285	30,957
Restructuring costs	2,542	0	0
Total operating expenses	83,740	155,211	102,251
Operating income (loss)	89,505	(4,965)	70,758
Investment income, net	2,850	1,635	1,236
Interest expense, net	(1,052)	(963)	0
Other income (expense) - changes in fair value of related party payable	2,071	(6,548)	(4,883)
Foreign exchange (loss) gain	(714)	1,123	10,594
Income (loss) before income taxes	92,660	(9,718)	77,705
Income tax provision	24,389	31,558	35,907
Net income (loss)	$ 68,271	$ (41,276)	$ 41,798
Earnings (loss) per share
Net income (loss) per share - basic (in usd per share)	$ 1.69	$ (1)	$ 1.03
Net income (loss) per share - diluted (in usd per share)	$ 1.63	$ (1)	$ 0.96
Weighted average number of shares outstanding
Weighted average number of shares outstanding - basic (in shares)	40,465	41,248	40,580
Weighted average number of shares outstanding - diluted (in shares)	41,765	41,248	43,619

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 68,271	$ (41,276)	$ 41,798
Other comprehensive income (loss), net of tax:
Foreign currency translation gain (loss)	134	(1,024)	(15,087)
Net other comprehensive income (loss), net of $28, $16, ($20) tax, respectively	165	116	(147)
Total other comprehensive income (loss), net of tax	299	(908)	(15,234)
Total comprehensive income (loss)	$ 68,570	$ (42,184)	$ 26,564

Consolidated Statements of Com4

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Unrealized gain (loss) on marketable securities, tax	$ 28	$ 16	$ (20)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 16,564	$ 39,215
Marketable securities	77,511	114,980
Accounts receivable	14,785	17,839
Inventories, net	6,157	3,258
Prepaid expenses and other current assets	8,958	5,894
Total current assets	123,975	181,186
Property and equipment, net	3,001	3,320
Goodwill	18,491	18,491
Intangible assets, net	92,289	22,837
Research and development tax credit receivable	5,272	1,775
Income tax deferred charge	0	10,342
Other non-current assets	10,249	7,531
Total assets	253,277	245,482
Current liabilities:
Current portion of long-term debt	111	268
Current portion of long-term related party payable	25,007	34,177
Accounts payable	7,477	7,105
Deferred revenue	2,007	2,223
Accrued expenses	50,926	17,222
Income taxes	414	1,200
Other current liabilities	597	226
Total current liabilities	86,539	62,421
Long-term debt, less current portion	156	547
Long-term related party payable, less current portion	73,918	135,170
Other non-current liabilities	7,084	5,275
Total liabilities	167,697	203,413
Shareholders’ equity:
Preferred shares, $0.01 nominal value; 50,000 shares authorized; none issued or outstanding at December 31, 2017 and December 31, 2016, respectively	0	0
Ordinary shares, nominal value of $0.01; 500,000 shares authorized; 41,463 issued and 39,346 outstanding at December 31, 2017, and 41,371 issued and outstanding at December 31, 2016	414	414
Treasury shares, at cost, 2,117 and 0 shares held at December 31, 2017 and December 31, 2016, respectively	(22,361)	0
Additional paid-in capital	393,478	385,020
Accumulated deficit	(262,685)	(319,800)
Accumulated other comprehensive loss	(23,266)	(23,565)
Total shareholders’ equity	85,580	42,069
Total liabilities and shareholders’ equity	$ 253,277	$ 245,482

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2017$ / sharesshares	Dec. 31, 2016€ / sharesshares	Dec. 31, 2016$ / sharesshares
Statement of Financial Position [Abstract]
Preferred shares, nominal value (in usd per share) | $ / shares	$ 0.01		$ 0.01
Preferred shares, shares authorized (in shares)	50,000,000	50,000,000	50,000,000
Preferred shares, shares issued (in shares)	0	0	0
Preferred shares, shares outstanding (in shares)	0	0	0
Ordinary shares, nominal value (in usd or euro per share) | (per share)	$ 0.01	€ 0.122	$ 0.01
Ordinary shares, shares authorized (in shares)	500,000,000	500,000,000	500,000,000
Ordinary shares, shares issued (in shares)	41,463,000	41,371,000	41,371,000
Ordinary shares, shares outstanding (in shares)	39,346,000	41,371,000	41,371,000
Treasury shares, held (in shares)	2,117,000	0	0

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Ordinary shares	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Treasury Shares
Beginning balance at Dec. 31, 2014	$ 25,025	$ 6,188	$ 346,582	$ (320,322)	$ (7,423)	$ 0
Beginning balance (in shares) at Dec. 31, 2014		40,191				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	41,798			41,798
Other comprehensive loss	(15,234)				(15,234)
Subscription of warrants	601		601
Exercise of stock options or warrants	6,389	$ 123	6,266
Exercise of stock options or warrants (in shares)		899
Vesting of restricted shares	0	$ 20	(20)
Vesting of free shares (in shares)		151
Stock-based compensation expense	7,741		7,741
Excess tax benefit from stock-based comp	2,814		2,814
Ending balance at Dec. 31, 2015	69,134	$ 6,331	363,984	(278,524)	(22,657)	$ 0
Ending balance (in shares) at Dec. 31, 2015		41,241				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(41,276)			(41,276)
Other comprehensive loss	(908)				(908)
Subscription of warrants	326		326
Exercise of stock options or warrants	114	$ 2	112
Exercise of stock options or warrants (in shares)		15
Vesting of restricted shares	0	$ 18	(18)
Vesting of free shares (in shares)		115
Stock-based compensation expense	14,679		14,679
Excess tax benefit from stock-based comp	0	$ (5,937)	5,937
Ending balance at Dec. 31, 2016	42,069	$ 414	385,020	(319,800)	(23,565)	$ 0
Ending balance (in shares) at Dec. 31, 2016		41,371				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	68,271			68,271
Other comprehensive loss	299				299
Exercise of stock options or warrants	396		396
Exercise of stock options or warrants (in shares)		69
Vesting of restricted shares	0
Vesting of free shares (in shares)		23
Stock-based compensation expense	8,062		8,062
Share repurchases	$ (22,361)					$ (22,361)
Share repurchases (in shares)	2,117					2,117
Ending balance at Dec. 31, 2017	$ 85,580	$ 414	$ 393,478	(262,685)	$ (23,266)	$ (22,361)
Ending balance (in shares) at Dec. 31, 2017		41,463				2,117
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment to accumulated deficit (see Note 2: Effect of New Accounting Standards)	$ (11,156)			$ (11,156)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 68,271,000	$ (41,276,000)	$ 41,798,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	4,883,000	14,489,000	13,132,000
Loss on disposal of property and equipment	0	110,000	0
(Gain) loss on sale of marketable securities	(411,000)	826,000	779,000
Foreign exchange loss (gain)	714,000	(349,000)	(8,969,000)
Grants recognized in research and development expenses	(539,000)	0	(1,498,000)
Remeasurement of related party acquisition-related contingent consideration	(31,040,000)	49,285,000	30,957,000
Remeasurement of related party financing-related contingent consideration	(2,071,000)	6,548,000	4,883,000
Change in deferred tax and income tax deferred charge	3,556,000	(4,000,000)	69,000
Stock-based compensation expense	8,072,000	14,679,000	7,741,000
Net changes in assets and liabilities
Accounts receivable	3,054,000	(10,050,000)	(8,440,000)
Inventories	(2,899,000)	1,831,000	3,036,000
Prepaid expenses and other current assets	(3,741,000)	3,412,000	(684,000)
Research and development tax credit receivable	(3,141,000)	397,000	2,975,000
Accounts payable & other current liabilities	595,000	(434,000)	(8,533,000)
Deferred revenue	(216,000)	(2,923,000)	3,815,000
Accrued expenses	13,187,000	6,764,000	3,376,000
Accrued income taxes	(786,000)	1,778,000	(393,000)
Earn-out payments for related party contingent consideration in excess of acquisition-date fair value	(31,636,000)	(20,252,000)	0
Royalty payments for related party payable in excess of original fair value	(4,429,000)	(2,469,000)	0
Other long-term assets and liabilities	(4,761,000)	535,000	249,000
Net cash provided by operating activities	16,662,000	18,901,000	84,293,000
Cash flows from investing activities:
Purchases of property and equipment	(591,000)	(1,201,000)	(1,629,000)
Acquisitions of businesses, including cash acquired and other adjustments	0	628,000	0
Purchase of intangible assets	(53,111,000)	0	0
Proceeds from sales of marketable securities	189,009,000	71,546,000	48,308,000
Purchases of marketable securities	(151,005,000)	(107,603,000)	(78,409,000)
Net cash used in investing activities	(15,698,000)	(36,630,000)	(31,730,000)
Cash flows from financing activities:
Reimbursement of loans	0	0	(4,911,000)
Reimbursement of conditional R&D grants	(115,000)	(277,000)	(747,000)
Earn-out payments for related party contingent consideration	(1,246,000)	(6,892,000)	(24,526,000)
Royalty payments for related party payable	0	(1,225,000)	(3,371,000)
Excess tax benefit from stock-based compensation	0	0	2,814,000
Cash proceeds from issuance of ordinary shares and warrants	404,000	440,000	6,990,000
Share repurchases	(22,361,000)	0	0
Net cash used in financing activities	(23,318,000)	(7,954,000)	(23,751,000)
Effect of foreign currency exchange rate changes on cash and cash equivalents	(297,000)	(166,000)	(3,508,000)
Net (decrease) increase in cash and cash equivalents	(22,651,000)	(25,849,000)	25,304,000
Cash and cash equivalents at January 1	39,215,000	65,064,000	39,760,000
Cash and cash equivalents at December 31	16,564,000	39,215,000	65,064,000
Supplemental disclosures of cash flow information:
Income tax paid	19,143,000	27,180,000	42,121,000
Interest paid	$ 1,050,000	$ 788,000	$ 4,738,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations. Avadel Pharmaceuticals plc (“Avadel,” the “Company,” “we,” “our,” or “us”) is a branded specialty pharmaceutical company. Avadel’s current revenues are primarily derived from products we market based on first-to-file New Drug Applications (“NDAs”) for pharmaceutical products previously sold in the U.S. without FDA approval (“Unapproved Marketed Products” or “UMDs”). In addition, through the acquisition of patient-focused, innovative products or businesses in the commercial- and or late-stage of development, Avadel seeks to provide solutions for overlooked and unmet medical needs, including our urology product, Noctiva™, which we in-licensed in 2017 and will begin marketing in 2018. Avadel also seeks to develop products that utilize our Micropump® drug delivery technology, such as our narcolepsy product which is in clinical trials. Avadel’s current commercial portfolio consists of three sterile injectable products, which were previously UMDs, used in the hospital setting, and Noctiva™, a urology product, which is the first and only FDA approved product for the treatment of nocturia due to nocturnal polyuria in adults. Nocturia is the condition of waking two or more times per night to void. Avadel is actively developing a fourth sterile, injectable UMD product for which it expects to file an NDA and seek FDA approval. In addition, Avadel is currently enrolling patients in our REST-ON Phase III clinical trial to evaluate the safety and efficacy of FT 218, a once-nightly formulation of sodium oxybate using Micropump®, for the treatment of EDS and cataplexy in patients suffering from narcolepsy. Narcolepsy is a rare sleep disorder with few approved treatment options. Avadel will continue to strategically evaluate potential UMDs and Micropump® based product candidates for development and approval, and will also look for synergistic acquisition targets to grow our company. The Company was incorporated in Ireland on December 1, 2015 as a private limited company, and re-registered as an Irish public limited company on November 21, 2016. Our headquarters are in Dublin, Ireland and we have operations in St. Louis, Missouri, United States, and Lyon, France. The Company is an Irish public limited company, or plc, and is the successor to Flamel Technologies S.A., a French société anonyme (“Flamel”), as the result of the merger of Flamel with and into the Company which was completed at 11:59:59 p.m., Central Europe Time, on December 31, 2016 (the “Merger”) pursuant to the agreement between Flamel and Avadel entitled Common Draft Terms of Cross-Border Merger dated as of June 29, 2016 (the “Merger Agreement”). Immediately prior to the Merger, the Company was a wholly owned subsidiary of Flamel. As a result of the Merger Agreement: • Flamel ceased to exist as a separate entity and the Company continued as the surviving entity and assumed all of the assets and liabilities of Flamel. • our authorized share capital is $5,500 divided into 500,000 ordinary shares with a nominal value of $0.01 each and 50,000 preferred shares with a nominal value of $0.01 each ◦ all outstanding ordinary shares of Flamel, €0.122 nominal value per share, were canceled and exchanged on a one-for-one basis for newly issued ordinary shares of the Company, $0.01 nominal value per share. This change in nominal value of our outstanding shares resulted in our reclassifying $5,937 on our balance sheet from ordinary shares to additional paid-in capital ◦ our Board of Directors is authorized to issue preferred shares on a non-pre-emptive basis, for a maximum period of five years, at which point such an authorization may be renewed by shareholders. The Board of Directors has discretion to dictate terms attached to the preferred shares, including voting, dividend, conversion rights, and priority relative to other classes of shares with respect to dividends and upon a liquidation. • all outstanding American Depositary Shares (ADSs) representing ordinary shares of Flamel were canceled and exchanged on a one-for-one basis for ADSs representing ordinary shares of the Company. Thus, the Merger changed the jurisdiction of our incorporation from France to Ireland, and an ordinary share of the Company held (either directly or represented by an ADS) immediately after the Merger continued to represent the same proportional interest in our equity owned by the holder of a share of Flamel immediately prior to the Merger. Prior to completion of the Merger, the Flamel ADSs were listed on the Nasdaq Global Market (“Nasdaq”) under the trading symbol “FLML”; and immediately after the Merger the Company’s ADSs were listed for and began trading on Nasdaq on January 3, 2017 under the trading symbol “AVDL.” Further details about the reincorporation, the Merger and the Merger Agreement are contained in our definitive proxy statement filed with the Securities and Exchange Commission on May 1, 2017. Under Irish law, the Company can only pay dividends and repurchase shares out of distributable reserves, as discussed further in the Company’s proxy statement filed with the SEC as of July 5, 2016. Upon completion of the Merger, the Company did not have any distributable reserves. On February 15, 2017, the Company filed a petition with the High Court of Ireland seeking the court’s confirmation of a reduction of the Company’s share premium so that it can be treated as distributable reserves for the purposes of Irish law. On March 6, 2017, the High Court issued its order approving the reduction of the Company’s share premium by $317,254 which can be treated as distributable reserves. Basis of Presentation. These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP). The consolidated financial statements include the accounts of the Company and all subsidiaries. All intercompany accounts and transactions have been eliminated. Revenue. Revenue includes sales of pharmaceutical products, amortization of licensing fees, and, if any, milestone payments for R&D achievements. Product Sales and Services Revenue is generally realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller’s price to the buyer is fixed or determinable, and collectability is reasonably assured. The Company records revenue from product sales when title and risk of ownership have been transferred to the customer, which is typically upon delivery to the customer and when the selling price is determinable. As is customary in the pharmaceutical industry, the Company’s gross product sales are subject to a variety of deductions in arriving at reported net product sales. These adjustments include estimates for product returns, chargebacks, payment discounts, rebates, and other sales allowances and are estimated based on analysis of historical data for the product or comparable products, as well as future expectations for such products. For generic products and branded products where the ultimate net selling price to customer is estimable, the Company recognizes revenues upon delivery to the wholesaler. For new product launches the Company recognizes revenue if sufficient data is available to determine product acceptance in the marketplace such that product returns may be estimated based on historical or analog product data and there is probable evidence of reorders and consideration is made of wholesaler inventory levels. As part of the third quarter 2016 launch of Akovaz, the Company determined that sufficient data was available to determine the ultimate net selling price to the customer and therefore recognized revenue upon delivery to our wholesaler customers. Prior to the second quarter 2016, the Company did not have sufficient historical or analog product data to estimate certain revenue deductions. As such, we could not accurately estimate the ultimate net selling price of our hospital portfolio of products and as a result delayed revenue recognition until the wholesaler sold the product through to end customers. During the second quarter of 2016, it was determined that we now had sufficient evidence, history, data and internal controls to estimate the ultimate selling price of our products upon shipment from our warehouse to our customers, the wholesalers. Accordingly, we discontinued the sell-through revenue approach and now recognize revenue once the product is delivered to the wholesaler. As a result of this change in accounting estimate, we recognized $5,981 in additional revenue, or $0.05 per diluted share, for the twelve months ended December 31, 2016 that previously would have been deferred until sold by the wholesalers to the hospitals. License and Research Revenue Our license and research revenues consist of fees and/or milestone payments. Non-refundable fees where we have continuing performance obligations are deferred and are recognized ratably over our projected performance period. We recognize milestone payments, which are typically related to regulatory, commercial or other achievements by us or our licensees and distributors, as revenues when the milestone is accomplished and collection is reasonably assured. To the extent that the expected timelines for such milestone payments are changed from initial estimates, the Company will record cumulative adjustments to reflect the revised timeline. For the year ended December 31, 2017, we recognized $404 of revenue from license agreements. Government Grants. The Company receives financial support for various research or investment projects from governmental agencies. From time to time we receive funds, primarily from the French government, to finance certain R&D projects. These funds are repayable on commercial success of the project. In the absence of commercial success, the Company is released of our obligation to repay the funds and as such the funds are recognized in the consolidated statements of income (loss) as an offset to R&D expense. The absence of commercial success must be formally confirmed by the granting authority. Should the Company wish to discontinue the R&D to which the funding is associated, the granting authority must be informed and a determination made as to how much, if any, of the grant must be repaid. Research and Development. R&D expenses consist primarily of costs related to clinical studies and outside services, personnel expenses, and other R&D expenses. Clinical studies and outside services costs relate primarily to services performed by clinical research organizations and related clinical or development manufacturing costs, materials and supplies, filing fees, regulatory support, and other third-party fees. Personnel expenses relate primarily to salaries, benefits and stock-based compensation. Other R&D expenses primarily include overhead allocations consisting of various support and facilities-related costs. R&D expenditures are charged to operations as incurred. The Company recognizes R&D tax credits received from the French government for spending on innovative R&D as an offset of R&D expenses. Stock-based Compensation. The Company accounts for stock-based compensation based on grant-date fair value estimated in accordance with ASC 718. The fair value of stock options and warrants is estimated using Black-Scholes option-pricing valuation models (“Black-Scholes model”). As required by the Black-Sholes model, estimates are made of the underlying volatility of AVDL stock, a risk-free rate and an expected term of the option or warrant. We estimated the expected term using a simplified method, as we do not have enough historical exercise data for a majority of such options and warrants upon which to estimate an expected term. The Company recognizes compensation cost, net of an estimated forfeiture rate, using the accelerated method over the requisite service period of the award. Income Taxes. We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine deferred tax assets and liabilities on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. We record uncertain tax positions in accordance with ASC 740 on the basis of a two-step process in which (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. We recognize interest and penalties related to unrecognized tax benefits in the income tax expense line in the accompanying consolidated statements of income (loss). Accrued interest and penalties are included on the related tax liability line in the consolidated balance sheets. Cash and Cash Equivalents. Cash and cash equivalents consist of cash on hand, cash on deposit and fixed term deposits which are highly liquid investments with original maturities of less than three months. Marketable Securities. The Company’s marketable securities are considered to be available for sale and are carried at fair value, with unrealized gains and losses, net of taxes, reported as a component of accumulated other comprehensive income (“AOCI”) in shareholders’ equity, with the exception of unrealized losses believed to be other-than-temporary, if any, which are reported in earnings in the current period. The cost of securities sold is based upon the specific identification method. Accounts Receivable. Accounts receivable are stated at amounts invoiced net of allowances for doubtful accounts and certain other gross to net deductions. The Company makes judgments as to our ability to collect outstanding receivables and provides allowances for the portion of receivables deemed uncollectible. Provision is made based upon a specific review of all significant outstanding invoices. A majority of accounts receivable is due from three significant customers. See Note 19: Company Operations by Product, Customer and Geographic Area. Inventories. Inventories consist of raw materials and finished products, which are stated at lower of cost or market determined under the first-in, first-out (“FIFO”) method. Raw materials used in the production of pre-clinical and clinical products are expensed as R&D costs when consumed. The Company establishes reserves for inventory estimated to be obsolete, unmarketable or slow-moving on a case by case basis. Property and Equipment. Property and equipment is stated at historical cost less accumulated depreciation. Depreciation and amortization are computed using the straight-line method over the following estimated useful lives: Laboratory equipment 4-8 years Software, office and computer equipment 3 years Leasehold improvements, furniture, fixtures and fittings 5-10 years Goodwill. Goodwill represents the excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed. The Company has determined that we operate in a single segment and has a single reporting unit associated with the development and commercialization of pharmaceutical products. The annual test for goodwill impairment is a two-step process. The first step is a comparison of the fair value of the reporting unit with its carrying amount, including goodwill. If this step indicates impairment, then, in the second step, the loss is measured as the excess of recorded goodwill over the implied fair value of the goodwill. Implied fair value of goodwill is the excess of the fair value of the reporting unit as a whole over the fair value of all separately identified assets and liabilities within the reporting unit. The Company tests goodwill for impairment annually and when events or changes in circumstances indicate that the carrying value may not be recoverable. During the fourth quarter of 2017, we performed our required annual impairment test of goodwill and have determined that no impairment of goodwill existed at December 31, 2017 or 2016. Long-Lived Assets. Long-lived assets include fixed assets and intangible assets. Intangible assets consist primarily of purchased licenses and intangible assets recognized as part of the Éclat and FSC acquisitions. Acquired IPR&D has an indefinite life and is not amortized until completion and development of the project, at which time the IPR&D becomes an amortizable asset, for which amortization of such intangible assets is computed using the straight-line method over the estimated useful life of the assets. Long-lived assets are reviewed for impairment whenever conditions indicate that the carrying value of the assets may not be fully recoverable. Such impairment tests are based on a comparison of the pretax undiscounted cash flows expected to be generated by the asset to the recorded value of the asset or other market based value approaches. If impairment is indicated, the asset value is written down to its market value if readily determinable or its estimated fair value based on discounted cash flows. Any significant changes in business or market conditions that vary from current expectations could have an impact on the fair value of these assets and any potential associated impairment. The Company has determined that no impairment existed at December 31, 2017 or 2016. Acquisition-related Contingent Consideration. The acquisition-related contingent consideration payables arising from the acquisition of Éclat Pharmaceuticals (i.e., our hospital products) and FSC (our pediatrics products) are accounted for at fair-value (see Item 8. Financial Statements and Supplementary Data and Note 10: Long-Term Related Party Payable ). The fair value of the warrants issued in connection with the Éclat acquisition are estimated using a Black-Scholes option pricing model. The fair value of acquisition-related contingent consideration payable is estimated using a discounted cash flow model based on the long-term sales or gross profit forecasts of the specified hospital or pediatric products using an appropriate discount rate. There are a number of estimates used when determining the fair value of these earn-out payments. These estimates include, but are not limited to, the long-term pricing environment, market size, market share the related products are forecast to achieve, the cost of goods related to such products and an appropriate discount rate to use when present valuing the related cash flows. These estimates can and often do change based on changes in current market conditions, competition, management judgment and other factors. Changes to these estimates can have and have had a material impact on our consolidated statements of income (loss) and balance sheets. Changes in fair value of these liabilities are recorded in the consolidated statements of income (loss) within operating expenses as changes in fair value of related party contingent consideration. Financing-related Royalty Agreements. We also entered into two royalty agreements with related parties in connection with certain financing arrangements. We elected the fair value option for the measurement of the financing-related contingent consideration payable associated with the royalty agreements with certain Deerfield and Broadfin entities, both of whom are related parties (see Note 10: Long-Term Related Party Payable ). The fair value of financing-related royalty agreements is estimated using the same components used to determine the fair value of the acquisition-related contingent consideration noted above, with the exception of cost of products sold. Changes to these components can also have a material impact on our consolidated statements of income (loss) and balance sheets. Changes in the fair value of this liability are recorded in the consolidated statements of income (loss) as other income (expense) - changes in fair value of related party payable. Foreign Currency Translation. At December 31, 2017, the reporting currency of the Company and our wholly-owned subsidiaries is the U.S. dollar. Prior to December 31, 2016, each of the Company’s non-U.S. subsidiaries and the parent entity, Flamel, used the Euro as their functional currency. At December 31, 2016, in conjunction with the Merger described above, Avadel determined the U.S. dollar is our functional currency. Subsidiaries and entities that do not use the U.S. dollar as their functional currency translate 1) profit and loss accounts at the average exchange rates during the reporting period, 2) assets and liabilities at period end exchange rates and 3) shareholders’ equity accounts at historical rates. Resulting translation gains and losses are included as a separate component of shareholders’ equity in accumulated other comprehensive loss. Assets and liabilities, excluding available-for-sale marketable securities, denominated in a currency other than the subsidiary’s functional currency are translated to the subsidiary’s functional currency at period end exchange rates with resulting gains and losses recognized in the consolidated statements of income (loss). Available-for-sale marketable securities denominated in a currency other than the subsidiary’s functional currency are translated to the subsidiary’s functional currency at period end exchange rates with resulting gains and losses recognized in the consolidated statements of comprehensive income (loss). Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, including marketable securities and contingent liabilities at the date of the consolidated financial statements and the reported amounts of sales and expenses during the periods presented. These estimates and assumptions are based on the best information available to management at the balance sheet dates and depending on the nature of the estimate can require significant judgments. Changes to these estimates and judgments can have and have had a material impact on our consolidated statements of income (loss) and balance sheets. Actual results could differ from those estimates under different assumptions or conditions.

Effect of New Accounting Standa

Effect of New Accounting Standards	12 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Effect of New Accounting Standards	Effect of New Accounting Standards In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2017-07, “ Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Costs .” The standard requires the service component of pension and other postretirement benefit expense to be presented in the same statement of income lines as other employee compensation costs, however, the other components will be presented outside of operating income. In addition, only the service cost component will be eligible for capitalization in assets. The standard is effective starting in 2018, with early adoption permitted. Retrospective application is required for the guidance on the statement of income presentation. Prospective application is required for the guidance on the cost capitalization in assets. The Company does not believe this standard will materially impact our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “ Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment.” This update eliminates step 2 from the goodwill impairment test, and requires the goodwill impairment test to be performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This guidance is effective for the Company in the first quarter of 2020. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company will assess the timing of adoption and impact of this guidance to future impairment considerations. In January 2017, the FASB issued ASU 2017-01, “ Business Combinations (Topic 805): Clarifying the Definition of a Business .” This update provides a screen to determine whether or not a set of assets is a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set of assets is not a business. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set of assets must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. This guidance is effective for the Company in the first quarter of fiscal 2018. Early adoption is permitted for transactions not previously reported in the Company’s consolidated financial statements. In September 2017, the Company entered into an Exclusive License and Assignment Agreement (“ELAA”) to acquire from Serenity Pharmaceuticals, LLC intellectual property rights to further develop and commercialize Noctiva in the United States. The Company elected to early adopt ASU 2017-01 and determined the intangible assets acquired as part of the ELAA should be accounted for as an acquisition of a single group of assets and not as a business combination. In October 2016, the FASB issued ASU 2016-16, “ Income Taxes (Topic 740), Intra-Entity Transfers of Assets Other Than Inventory ,” which requires companies to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 is effective for annual reporting periods, and interim periods therein, beginning after December 15, 2017. The Company elected to early adopt ASU 2016-16 on a modified-retrospective basis as of January 1, 2017. Adoption of ASU 2016-16 eliminated the $11,156 income tax deferred charge recorded within the consolidated balance sheet as of December 31, 2016 and such elimination is reflected as an adjustment to accumulated deficit as of January 1, 2017. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments .” ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for the Company for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. ASU 2016-15 should be applied retrospectively and early adoption is permitted, including adoption in an interim period. The Company does not believe this standard will materially impact our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09 “ Revenue from Contracts with Customers” which supersedes the most current revenue recognition requirements. This ASU requires entities to recognize revenue in a way that depicts the transfer of goods or services to customers in an amount that reflects the consideration which the entity expects to be entitled to in exchange for those goods or services. Through May 2016, the FASB issued ASU 2016-08 “ Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” ASU 2016-10 “ Identifying Performance Obligations and Licensing,” and ASU 2016-12, “ Narrow-Scope Improvements and Practical Expedients,” which provide supplemental adoption guidance and clarification to ASU 2014-09, respectively. These ASUs will be effective for annual and interim periods beginning after December 15, 2017, with early adoption for annual and interim periods beginning after December 15, 2016 permitted and should be applied retrospectively to each prior reporting period presented or as a modified retrospective adjustment as of the date of adoption. The Company has completed our evaluation and assessment of the potential impacts of adopting this pronouncement on our consolidated financial statements and related disclosures. Based on this assessment, we will adopt the pronouncement under the modified retrospective method of transition in the first quarter of 2018. The Company does not expect adoption of the new standard will have a material effect on the overall timing or amount of revenue recognized when compared to current accounting standards. The impact to the Company of adopting the new revenue standard primarily relates to additional and expanded disclosures. In March 2016, the FASB issued ASU 2016-09, “ Improvements to Employee Share-Based Payment Accounting ” which amends Accounting Standards Codification (“ASC”) Topic 718 “Compensation – Stock Compensation”. This update simplifies several aspects of accounting for share-based payment awards to employees, including the accounting for income taxes, classification of awards as either equity or liabilities, forfeitures and classification in the statement of cash flows. We adopted the standard on a prospective basis with the effect of adoption reflected for the interim periods after the year beginning January 1, 2017 as required by the standard. The primary effects of adoption were immaterial to the Company’s consolidated financial statements for the year ended December 31, 2017. In February 2016, the FASB issued ASU 2016-02, “ Leases ” which supersedes ASC 840 “ Leases ” and creates a new topic, ASC 842 “ Leases .” This update requires lessees to recognize on their balance sheet a lease liability and a lease asset for all leases, including operating leases, with a term greater than 12 months. The update also expands the required quantitative and qualitative disclosures surrounding leases. This update is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years, with earlier application permitted. This update will be applied using a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The Company is currently evaluating the effect of this update on our consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities .” The amendments in this update address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2017, and requires a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. Early adoption is not permitted. The new guidance will require the change in fair value of equity investments with readily determinable fair values to be recognized through the statement of income. Upon adoption, the change in the fair value of our available-for-sale equity investments will be recognized in our consolidated statement of income (loss) rather than as a component of our consolidated statement of comprehensive income (loss). The Company cannot reasonably estimate at this time the impact ASU 2016-01 will have on its financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company is required to measure certain assets and liabilities at fair value, either upon initial recognition or for subsequent accounting or reporting. For example, we use fair value extensively when accounting for and reporting certain financial instruments, when measuring certain contingent consideration liabilities and in the initial recognition of net assets acquired in a business combination. Fair value is estimated by applying the hierarchy described below, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: ASC 820, Fair Value Measurements and Disclosures defines fair value as a market-based measurement that should be determined based on the assumptions that marketplace participants would use in pricing an asset or liability. When estimating fair value, depending on the nature and complexity of the asset or liability, we may generally use one or each of the following techniques: • Income approach, which is based on the present value of a future stream of net cash flows. • Market approach, which is based on market prices and other information from market transactions involving identical or comparable assets or liabilities. As a basis for considering the assumptions used in these techniques, the standard establishes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value as follows: • Level 1 - Quoted prices for identical assets or liabilities in active markets. • Level 2 - Quoted prices for similar assets or liabilities in active markets, or quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are directly or indirectly observable, or inputs that are derived principally from, or corroborated by, observable market data by correlation or other means. • Level 3 - Unobservable inputs that reflect estimates and assumptions. The following table summarizes the financial instruments measured at fair value on a recurring basis classified in the fair value hierarchy (Level 1, 2 or 3) based on the inputs used for valuation in the accompanying consolidated balance sheets: As of December 31, 2017 As of December 31, 2016 Fair Value Measurements: Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Marketable securities (see Note 4: Marketable Securities ) Equity securities $ 468 $ — $ — $ 4,033 $ — $ — Money market funds 44,481 — — — — — Corporate bonds — 9,262 — — 57,348 — Government securities - U.S. — 19,050 — — 42,814 — Government securities - Non-U.S. — — — — 233 — Other fixed-income securities — 4,250 — — 10,471 — Other securities — — — — 81 — Total assets $ 44,949 $ 32,562 $ — $ 4,033 $ 110,947 $ — Related party payable (see Note 10: Long-Term Related Party Payable ) — — 98,925 — — 169,347 Total liabilities $ — $ — $ 98,925 $ — $ — $ 169,347 A review of fair value hierarchy classifications is conducted on a quarterly basis. Changes in the observability of valuation inputs may result in a reclassification for certain financial assets or liabilities. During the fiscal year ended December 31, 2017 , there were no transfers in and out of Level 1, 2, or 3. During the twelve months ended December 31, 2017 , 2016 and 2015 , we did not recognize any other-than-temporary impairment loss. Some of the Company’s financial instruments, such as cash and cash equivalents, accounts receivable and accounts payable, are reflected in the balance sheet at carrying value, which approximates fair value due to their short-term nature. Additionally, the Company’s long-term debt is reflected in the balance sheet at carrying value, which approximates fair value, as these represent non-interest bearing grants from the French government and are repayable only if the research project is technically or commercially successful.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The Company has investments in available-for-sale marketable securities which are recorded at fair market value. Unrealized gains and losses are recorded as other comprehensive income (loss) in shareholders’ equity, net of income tax effects. The following tables show the Company’s available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category as of December 31, 2017 and 2016 , respectively: 2017 Marketable Securities: Adjusted Cost Unrealized Gains Unrealized Losses Fair Value Equity securities $ 443 $ 31 $ (6 ) $ 468 Money market funds 44,525 — (44 ) 44,481 Corporate bonds 9,285 1 (24 ) 9,262 Government securities - U.S. 19,080 — (30 ) 19,050 Other fixed-income securities 4,259 — (9 ) 4,250 Total $ 77,592 $ 32 $ (113 ) $ 77,511 2016 Marketable Securities: Adjusted Cost Unrealized Gains Unrealized Losses Fair Value Equity securities $ 3,689 $ 409 $ (65 ) $ 4,033 Corporate bonds 57,871 89 (612 ) 57,348 Government securities - U.S. 43,049 515 (750 ) 42,814 Government securities - Non-U.S. 247 — (14 ) 233 Other fixed-income securities 10,281 221 (31 ) 10,471 Other securities 81 — — 81 Total $ 115,218 $ 1,234 $ (1,472 ) $ 114,980 We determine realized gains or losses on the sale of marketable securities on a specific identification method. We recognized gross realized gains of $1,677 , $1,265 , and $241 for the twelve months ended December 31, 2017 , 2016 , and 2015 , respectively. These realized gains were offset by realized losses of $1,390 , $586 , and $677 for the twelve-months ended December 31, 2017 , 2016 , and 2015 , respectively. We reflect these gains and losses as a component of investment income in the accompanying consolidated statements of income (loss). The following table summarizes the estimated fair value of our investments in marketable debt securities, accounted for as available-for-sale securities and classified by the contractual maturity date of the securities as of December 31, 2017 : Maturities Marketable Debt Securities: Less than 1 Year 1-5 Years 5-10 Years Greater than 10 Years Total Corporate bonds 1,033 6,826 1,403 — 9,262 Government securities - U.S. 50 17,509 977 514 19,050 Other fixed-income securities — 4,250 — — 4,250 Total $ 1,083 $ 28,585 $ 2,380 $ 514 $ 32,562 The Company has classified our investment in available-for-sale marketable securities as current assets in the consolidated balance sheets as the securities need to be available for use, if required, to fund current operations. There are no restrictions on the sale of any securities in our investment portfolio.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories The principal categories of inventories, net reserves of $1,039 and $3,223 at December 31, 2017 and 2016 , respectively, are comprised of the following: Inventory: 2017 2016 Finished goods $ 4,774 $ 2,429 Raw materials 1,383 829 Total $ 6,157 $ 3,258

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The principal categories of property and equipment, net at December 31, 2017 and 2016 , respectively, are as follows: Property and Equipment, net: 2017 2016 Laboratory equipment $ 10,135 $ 9,019 Software, office and computer equipment 3,115 2,519 Furniture, fixtures and fittings 4,779 4,239 Less - accumulated depreciation (15,028 ) (12,457 ) Total $ 3,001 $ 3,320 Depreciation expense for the years ended December 31, 2017 , 2016 and 2015 was $1,224 , $601 and $568 , respectively.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions On February 5, 2016, the Company acquired FSC, a specialty pharmaceutical company dedicated to providing innovative solutions to unmet medical needs for pediatric patients, from Deerfield CSF, LLC, a Deerfield Management company (“Deerfield CSF”), a related party. The Company disposed of these pediatric assets on February 16, 2018. See Note 21: Subsequent Events . This acquisition has been accounted for using the acquisition method of accounting and, accordingly, its results are included in the Company’s consolidated financial statements from the date of acquisition. Total consideration to acquire FSC was $21,659 , and was funded with a combination of the following, partially offset by $ 467 as a result of a net working capital settlement from the seller: • $15,000 long-term liability to Deerfield CSF. Under the terms of the acquisition agreement, the Company will pay $1,050 annually for five years with a final payment in January 2021 of $15,000 . • an estimate of $ 6,659 in contingent consideration to Deerfield CSF. Under the terms of the acquisition agreement, the Company shall pay quarterly a 15% royalty on the net sales of certain FSC products, up to $12,500 for a period not exceeding ten years. These items are reported in related party payable within the Company’s consolidated balance sheet, and is further disclosed in Note 10: Long-Term Related Party Payable . The fair values assigned to the acquired assets and liabilities have been recognized as follows: Assigned Fair Value: Amount Accounts receivable $ 142 Inventories 1,135 Prepaid expenses and other current assets 1,712 Intangible assets: Acquired product marketing rights 16,600 Acquired developed technology 4,300 Deferred tax assets 853 Other assets 277 Accounts payable and other liabilities (3,827 ) Total $ 21,192 A portion of the transaction attributable to certain intangible assets was taxable for income tax purposes resulting in recording some of the assets at fair value for both book and tax purposes. Transaction expenses were not material. The useful lives on FSC acquired intangible assets range from nine to fifteen years. After its acquisition on February 5, 2016, FSC contributed $5,985 to the Company’s net sales for the twelve-month period ended December 31, 2016. FSC incurred a loss of $5,839 for the twelve-month period ended December 31, 2016. Had the FSC acquisition been completed as of the beginning of 2015, the Company’s unaudited pro forma net revenue and net income (loss) for the twelve months ended December 31, 2016 and 2015 would have been as follows: Pro Forma Net Revenue and Income (Loss): 2016 2015 Net revenues $ 150,721 $ 178,104 Net income (loss) (42,290 ) 30,965

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets The Company’s amortizable and unamortizable intangible assets at December 31, 2017 and 2016 , respectively, are as follows: 2017 2016 Goodwill and Intangible Assets: Gross Value Accumulated Amortization Net Carrying Amount Gross Value Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Acquired developed technology - Noctiva $ 73,111 $ (1,401 ) $ 71,710 $ — $ — $ — Acquired developed technology - Vazculep 12,061 (9,616 ) 2,445 12,061 (8,801 ) 3,260 Acquired product marketing rights 16,600 (2,132 ) 14,468 16,600 (1,019 ) 15,581 Acquired developed technology 4,300 (634 ) 3,666 4,300 (304 ) 3,996 Total amortizable intangible assets $ 106,072 $ (13,783 ) $ 92,289 $ 32,961 $ (10,124 ) $ 22,837 Unamortizable intangible assets: Goodwill $ 18,491 $ — $ 18,491 $ 18,491 $ — $ 18,491 Total unamortizable intangible assets $ 18,491 $ — $ 18,491 $ 18,491 $ — $ 18,491 The Company recorded amortization expense related to amortizable intangible assets of $3,659 , $13,888 and $12,564 for the years ended December 31, 2017 , 2016 and 2015 , respectively. During the period, the Company acquired $73,111 in developed technology as part of the ELAA with Serenity Pharmaceuticals, LLC. The aggregate cost was composed of an upfront payment of $50,000 , an accrued payment of $20,000 due within one year, and $3,111 of transaction costs. The Company will amortize the developed technology over a 13 year period beginning October 1, 2017. Amortizable intangible assets are amortized over their estimated useful lives, which range from three to fifteen years, using the straight-line method. At December 31, 2017, total future amortization of intangible assets for the next five years is as follows: Estimated Amortization Expense: Amount 2018 $ 7,882 2019 7,882 2020 7,882 2021 7,067 2022 7,067

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt French government agencies provide financing to French companies for R&D. At December 31, 2017 and 2016 , the Company had outstanding loans of $267 and $815 , respectively for various programs. These loans do not bear interest and are repayable only in the event the research project is technically or commercially successful. Potential repayment is scheduled to occur through 2019. During the years ended December 31, 2017 , 2016 and 2015 , the Company repaid $115 , $277 and $747 , of loans associated with specific research projects, respectively. In addition, during 2017 and 2015 the Company received waivers of repayment for the remaining portion of certain loans of $539 and $1,498 , respectively, on the basis of limited commercial and technical success. Amounts waived are reported as reductions to R&D expenses in the Company’s consolidated statements of income (loss). No such waivers were received during 2016.

Long-Term Related Party Payable

Long-Term Related Party Payable	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Related Party Payable	Long-Term Related Party Payable Long-term related party payable and related activity are reported at fair value and consist of the following at December 31, 2017 and 2016 , respectively: Activity during the Twelve Months Ended December 31, 2017 Changes in Fair Value of Related Party Payable Balance, December 31, 2016 Payments to Related Parties Operating Income Other Income Balance, Acquisition-related contingent consideration: Warrants - Éclat Pharmaceuticals (a) $ 11,217 $ — $ (8,738 ) $ — $ 2,479 Earn-out payments - Éclat Pharmaceuticals (b) 121,377 (31,636 ) (21,997 ) — 67,744 Royalty agreement - FSC (c) 7,291 (1,246 ) (305 ) — 5,740 Financing-related: — Royalty agreement - Deerfield (d) 9,794 (2,999 ) — (1,403 ) 5,392 Royalty agreement - Broadfin (e) 4,668 (1,430 ) — (668 ) 2,570 Long-term liability - FSC (f) 15,000 — — — 15,000 Total related party payable 169,347 $ (37,311 ) $ (31,040 ) $ (2,071 ) 98,925 Less: Current portion (34,177 ) (25,007 ) Total long-term related party payable $ 135,170 $ 73,918 Each of the above items is associated with related parties as further described in Note 20: Related Party Transactions. (a) As part of the consideration for the Company’s acquisition of Éclat Pharmaceuticals, LLC on March 13, 2012, the Company issued two warrants to a related party with a six -year term which allow for the purchase of a combined total of 3,300 ordinary shares of Avadel. One warrant is exercisable for 2,200 ordinary shares at an exercise price of $7.44 per share, and the other warrant is exercisable for 1,100 ordinary shares at an exercise price of $11.00 per share. On February 23, 2018, the related party exercised in full the warrant for 2,200 ordinary shares. On March 12, 2018, the remaining warrant for 1,100 ordinary shares expired worthless. See Note 21: Subsequent Events . The fair value of the warrants is estimated on a quarterly basis using a Black-Scholes option pricing model with the following assumptions as of December 31: Assumptions for the Warrant Valuation: 2017 2016 Stock price $ 8.20 $ 10.39 Weighted average exercise price per share 8.63 8.63 Expected term (years) 0.25 1.25 Expected volatility 37.90 % 54.20 % Risk-free interest rate 1.39 % 0.94 % Expected dividend yield — — These Black-Scholes fair value measurements are based on significant inputs not observable in the market and thus represent a level 3 measurement as defined in ASC 820. The fair value of the warrant consideration is most sensitive to movement in the Company’s share price and expected volatility at the balance sheet date. Expected term : The expected term of the options or warrants represents the period of time between the grant date and the time the options or warrants are either exercised or forfeited, including an estimate of future forfeitures for outstanding options or warrants. Given the limited historical data and the grant of stock options and warrants to a limited population, the simplified method has been used to calculate the expected life. Expected volatility : The expected volatility is calculated based on an average of the historical volatility of the Company’s stock price. Risk-free interest rate : The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant and a maturity that approximates the expected term. Expected dividend yield : The Company has not distributed any dividends since our inception and has no plan to distribute dividends in the foreseeable future. At the closing date of the 2012 Éclat acquisition and at December 31, 2017 , it was uncertain as to whether the Company would ultimately fulfill our obligation under these warrants using Company shares or cash. Accordingly, pursuant to the guidance of ASC 480, the Company determined that these warrants should be classified as a liability. This classification as a liability was further supported by the Company’s determination, pursuant to the guidance of ASC 815-40-15-7(i), that these warrants could also not be considered as being indexed to the Company’s own stock, on the basis that the exercise price for the warrants is determined in U.S. dollars, although the functional currency of the Company at the closing date of the Éclat acquisition was the Euro. (b) In March 2012, the Company acquired all of the membership interests of Éclat from Breaking Stick Holdings, L.L.C. (“Breaking Stick”, formerly Éclat Holdings), an affiliate of Deerfield. Breaking Stick is majority owned by Deerfield, with a minority interest owned by the Company’s CEO, and certain other current and former employees. As part of the consideration, the Company committed to provide quarterly earn-out payments equal to 20% of any gross profit generated by certain Éclat products. These payments will continue in perpetuity, to the extent gross profit of the related products also continue in perpetuity. (c) In February 2016, the Company acquired all of the membership interests of FSC from Deerfield. The consideration for this transaction in part included a commitment to pay quarterly a 15% royalty on the net sales of certain FSC products, up to $12,500 for a period not exceeding ten years. This obligation was assumed by the buyer as part of the disposition of the pediatrics products on February 16, 2018. See Note 21: Subsequent Events. (d) As part of a February 2013 debt financing transaction conducted with Deerfield, the Company received cash of $2,600 in exchange for entering into a royalty agreement whereby the Company shall pay quarterly a 1.75% royalty on the net sales of certain Éclat products until December 31, 2024. In connection with such debt financing transaction, the Company granted Deerfield a security interest in the product registration rights of the Eclat products. (e) As part of a December 2013 debt financing transaction conducted with Broadfin Healthcare Master Fund, a related party and current shareholder, the Company received cash of $2,200 in exchange for entering into a royalty agreement whereby the Company shall pay quarterly a 0.834% royalty on the net sales of certain Éclat products until December 31, 2024. (f) In February 2016, the Company acquired all of the membership interests of FSC from Deerfield. The consideration for this transaction in part consists of payments totaling $1,050 annually for five years with a final payment in January 2021 of $15,000 . Substantially all of FSC’s, and its subsidiaries, assets are pledged as collateral under this agreement. This obligation was assumed by the buyer as part of the disposition of the pediatrics products on February 16, 2018. See Note 21: Subsequent Events. At December 31, 2017 , the fair value of each related party payable listed in (b) through (e) above was estimated using a discounted cash flow model based on estimated and projected annual net revenues or gross profit, as appropriate, of each of the specified Éclat and FSC products. These fair value measurements are based on significant inputs not observable in the market and thus represent a level 3 measurement as defined in ASC 820. The most significant of these inputs are the Company’s estimates of future market share and the risk-adjusted discount rate. New entrants into the markets for any of the Company’s products can put downward pressure on volume and price. To the extent that these factors reduce the Company’s expectations of future market share or selling price, the estimated future earn-out payments and the respective fair value of contingent consideration would be reduced. The Company uses an appropriate risk-adjusted discount rate within the discounted cash flow models ranging from 15% to 22% . Decreases in the discount rate would increase the calculated fair value of contingent consideration. Subsequent changes in the fair value of the acquisition-related related party payables, resulting primarily from management’s revision of key assumptions, will be recorded in the consolidated statements of income (loss) in the line items entitled “(Gain) loss - changes in fair value of related party contingent consideration” for items noted in (b) and (c) above and in “Other income (expense) - changes in fair value of related party payable” for items (d) and (e) above. See Note 1 : Summary of Significant Accounting Policies under the caption Acquisition-related Contingent Consideration and Financing-related Royalty Agreements for more information on key assumptions used to determine fair value of these liabilities. The Company has chosen to make a fair value election pursuant to ASC 825, “Financial Instruments” for our royalty agreements detailed in items (d) and (e) above. These financing-related liabilities are recorded at fair market value on the consolidated balance sheets and the periodic change in fair market value is recorded as a component of “Other expense – changes in fair value of related party payable” on the consolidated statements of income (loss). The following table summarizes changes to the related party payables, a recurring Level 3 measurement, for the twelve-month periods ended December 31, 2017 , 2016 and 2015 : Related Party Payable: Balance Balance at December 31, 2014 114,750 Payment of related party payable (27,897 ) Fair value adjustments (1) 35,840 Balance at December 31, 2015 122,693 Additions (2) 21,659 Payment of related party payable (30,838 ) Fair value adjustments (1) 55,833 Balance at December 31, 2016 169,347 Payment of related party payable (37,311 ) Fair value adjustments (1) (33,111 ) Balance at December 31, 2017 98,925 (1) Fair value adjustments are reported as “(Gain) loss - changes in fair value of related party contingent consideration” and “Other income (expense) - changes in fair value of related party payable” in the Consolidated Statements of Income (Loss). (2) Relates to the acquisition of FSC. See items (c) and (f) above.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In 2016, we changed our jurisdiction of incorporation from France to Ireland by merging with and into our wholly owned Irish subsidiary. Information about the reincorporation was included in the definitive proxy statement filed with the Securities and Exchange Commission on July 5, 2016. Accordingly, beginning in 2016, the Company reports the Irish tax jurisdiction as our Domestic jurisdiction. For periods prior to 2016, the French tax jurisdiction was the Domestic jurisdiction. The components of income (loss) before income taxes for the years ended December 31, are as follows: Income (Loss) Before Income Taxes: 2017 2016 2015 Ireland $ (3,123 ) $ (22,866 ) $ (29,469 ) United States 92,754 32,786 100,552 France 3,029 (19,638 ) 6,622 Total income (loss) before income taxes $ 92,660 $ (9,718 ) $ 77,705 The income tax provision consists of the following for the years ended December 31: Income Tax Provision: 2017 2016 2015 Current: United States - Federal $ 18,064 $ 30,738 $ 33,289 United States - State 331 1,081 970 France 265 5,267 1,657 Total current 18,660 37,086 35,916 Deferred: United States - Federal 4,686 (6,443 ) 504 United States - State 1,043 (23 ) 1,234 France — 938 (1,747 ) Total deferred 5,729 (5,528 ) (9 ) Income tax provision $ 24,389 $ 31,558 $ 35,907 The reconciliation between Domestic income taxes at the statutory rate and the Company’s provision (benefit) for income taxes is as follows for the years ended December 31: Reconciliation to Effective Income Tax Rate: 2017 2016 2015 Statutory tax rate (1) 12.5 % 12.5 % 33.3 % Differences in international tax rates 22.2 % (31.9 )% 11.0 % Nondeductible changes in fair value of contingent consideration (11.6 )% (165.0 )% 11.9 % Income tax deferred charge — % (9.7 )% 1.3 % Change in valuation allowances (0.7 )% 11.8 % (9.6 )% Nondeductible stock based compensation (0.4 )% (14.8 )% 1.3 % Cross border merger 0.3 % (100.6 )% — % Unrealized tax benefits 1.4 % (15.2 )% 0.4 % State and local taxes (net of federal) 0.3 % (9.6 )% 1.5 % Change in U.S. tax law 3.8 % — % — % Other (1.5 )% (2.3 )% (4.9 )% Effective income tax rate 26.3 % (324.8 )% 46.2 % Income tax provision (benefit) - at statutory tax rate (1) $ 11,582 $ (1,215 ) $ 25,876 Differences in international tax rates 20,557 3,097 8,547 Nondeductible changes in fair value of contingent consideration (10,779 ) 16,036 9,249 Income tax deferred charge — 938 980 Change in valuation allowances (610 ) (1,143 ) (7,425 ) Nondeductible stock based compensation (375 ) 1,436 1,004 Cross-border merger 265 9,773 — Unrecognized tax benefits 1,296 1,475 290 State and local taxes (net of federal) 252 934 1,170 Change in U.S. tax law 3,513 — — Other (1,312 ) 227 (3,784 ) Income tax provision - at effective income tax rate $ 24,389 $ 31,558 $ 35,907 (1) The statutory rate reflects the Irish statutory tax rate of 12.5% for fiscal 2017 and 2016, and the French statutory tax rate of 33.3% for fiscal 2015. In 2017, the income tax provision decreased by $7,169 when compared to the same period in 2016. The decrease in the income tax provision was primarily driven by a significant reduction in the amount of taxable income recorded in the United States in 2017, when compared to 2016. In 2017, the Company did not incur any significant additional income tax provision associated with the Cross-Border Merger as a majority of the transaction was completed in 2016. In 2017, the Company recorded $3,513 of tax provision associated with the Tax Cuts and Jobs Act signed into law in the United States in December of 2017. In 2016, the income tax provision decreased by $4,349 when compared to the same period in 2015. The primary reason for the decrease in the income tax provision is a substantially lower level of pre-tax book income in the United States and France. Increases in the amount of nondeductible expenses due to changes in the fair value of contingent consideration and a reduced amount of income tax benefit from the release of valuation allowances partially offset the income tax benefit from the reduced amount of pre-tax book income in 2016, when compared to 2015. The Company also recorded $9,773 of income tax provision in 2016 related to the cross-border merger. Unrecognized Tax Benefits The Company or one of our subsidiaries files income tax returns in Ireland, France, United States and various states. With few exceptions, the Company is no longer subject to Irish, French, US Federal, and state and local examinations for years before 2013. The Internal Revenue Service (IRS) commenced an examination of the Company’s US income tax return for 2015 in the 4th quarter of 2016 that is anticipated to be completed by the end of 2018. The following table summarizes the activity related to the Company’s unrecognized tax benefits for the twelve months ended December 31: Unrecognized Tax Benefit Activity 2017 2016 2015 Balance at January 1: $ 1,686 $ 448 $ — Additions based on tax positions related to the current year 2,268 1,578 448 Reductions for tax positions of prior years — (340 ) — Balance at December 31: $ 3,954 $ 1,686 $ 448 It is reasonably possible that within the next twelve months, as a result of activities performed in various jurisdictions, that the unrecognized tax benefits could change by up to $600 . Interest and penalties could change by up to $500 . At December 31, 2017 , 2016, and 2015, there are $3,349 , $1,565 , and $291 of unrecognized tax benefits that if recognized would affect the annual effective tax rate. The Company recognizes interest and penalties accrued related to unrecognized tax benefits in income tax expense. During the years ended December 31, 2017 , 2016, and 2015, the Company recognized approximately $304 , $26 , and $0 in interest and penalties. The Company had approximately $331 , and $26 for the payment of interest and penalties accrued at December 31, 2017 , and 2016, respectively. Deferred Tax Assets (Liabilities) Deferred income tax provisions reflect the effect of temporary differences between consolidated financial statement and tax reporting of income and expense items. The net deferred tax assets/liabilities at December 31, 2017 and 2016 resulted from the following temporary differences: Net Deferred Tax Assets and Liabilities: 2017 2016 Deferred tax assets: Net operating loss carryforwards $ 9,831 $ 11,566 Amortization 7,563 — Stock based compensation 4,375 5,012 Fair value royalty agreements 635 3,386 Fair value contingent consideration 870 2,152 Other 406 583 Gross deferred tax assets 23,680 22,699 Deferred tax liabilities: Amortization (2,419 ) (4,349 ) Accounts receivable (936 ) (3,319 ) Prepaid expenses (1,094 ) — Gross deferred tax liabilities (4,449 ) (7,668 ) Less: valuation allowances (15,354 ) (7,599 ) Net deferred tax assets $ 3,877 $ 7,432 At December 31, 2017, the Company had $39,574 of net operating losses in Ireland and $698 of net operating losses in France that do not have an expiration date and $11,190 of net operating losses in the United States that expire 2034 through 2035. The US net operating losses were acquired as part of the acquisition of FSC. A valuation allowance is recorded if, based on the weight of available evidence, it is more likely than not that a deferred tax asset will not be realized. This assessment is based on an evaluation of the level of historical taxable income and projections for future taxable income. For the year ended December 31, 2017 the Company recorded $4,963 of valuation allowances related to Irish net operating losses, $233 of valuation allowances related to French net operating losses and $309 of valuation allowances on U.S. net operating losses. The U.S. net operating losses are subject to an annual limitation as a result of the FSC acquisition under Internal Revenue Code Section 382 and will not be fully utilized before they expire. We recorded a valuation allowance against all of our net operating losses in Ireland and France as of both December 31, 2017, and December 31, 2016. We intend to continue maintaining a full valuation allowance on the Irish and French net operating losses until there is sufficient evidence to support the reversal of all or some portion of these allowances. At December 31, 2017, the Company has unremitted earnings of $3,038 outside of Ireland as measured on a US GAAP basis. Whereas the measure of earnings for purposes of taxation of a distribution may be different for tax purposes, these earnings, which are considered to be invested indefinitely, would become subject to income tax if they were remitted as dividends or if the Company were to sell our stock in the subsidiaries, net of any prior income taxes paid. It is not practicable to estimate the amount of deferred tax liability on such earnings, if any. Research and Development Tax Credits Receivable The French and Irish governments provide tax credits to companies for spending on innovative R&D. These credits are recorded as an offset of R&D expenses and are credited against income taxes payable in years after being incurred or, if not so utilized, are recoverable in cash after a specified period of time, which may differ depending on the tax credit regime. As of December 31, 2017, the Company’s net Research tax credit receivable amounts to $5,272 and represents a French gross research tax credit of $4,754 and an Irish gross research tax credit of $518 . As of December 31, 2016, the Company’s net research tax credit receivable amounted to $1,775 and represented a French gross research tax credit of $3,376 , partially offset by current income tax payable of $1,601 . The Company utilized $4,001 of research tax credits in 2016 to offset the tax cost of the cross-border merger. Income Tax Deferred Charge On December 16, 2014, the Company transferred all of our intangible intellectual property from its French entity to our Irish entity as part of a global reorganization. The intellectual property includes patents on drug delivery platforms, clinical data sets and other intangible assets related to the pipeline of proprietary products in development. This intra-entity transaction resulted in a charge of $14,088 of related taxes to the French government in December 2014. As this represents an intra-entity transaction, no deferred tax asset was originally recognized, but rather was recorded as $986 of prepaid expenses and $13,102 of a long-term income tax deferred charge asset in accordance with ASC 740-10-25-3 (e). This income tax deferred charge asset is amortized over the tax life of the asset at a rate of 7% per year and will result in tax relief in Ireland of $8,500 from 2016 to 2029, subject to the ability to realize tax benefits for additional deductions. At December 31, 2016, the balance of these respective accounts was classified as prepaid expenses of $814 and income tax deferred charge asset of $10,342 . In 2017, the Company adopted the provisions of ASU 2016-16, related to Intra-Entity Transfers of Assets Other Than Inventory. Adoption of ASU 2016-16 eliminated the $11,156 income tax deferred charge recorded within the consolidated balance sheet as of December 31, 2016. In addition to the elimination of the income tax deferred charge, the Company recorded a deferred tax asset of $7,954 related to the remaining unamortized tax basis of the intangible intellectual property. A full valuation allowance was recorded against the deferred tax asset as sufficient evidence does not exist at this time that the Company will be able to utilize these benefits. Cross-Border Merger In 2016, we changed our jurisdiction of incorporation from France to Ireland by merging with and into our wholly owned Irish subsidiary. Information about the reincorporation was included in the definitive proxy statement filed with the Securities and Exchange Commission on July 5, 2016. Prior to the merger, the Company submitted a request to the French tax authorities seeking to benefit from a special regime for mergers and demergers, conditional upon a formal consent of the French tax authority, which would allow for the deferral of a portion of the tax cost of the cross-border merger. In 2017, the Company received a letter from the French tax authorities indicating that our request to benefit from the special regime had been declined. Completion of the cross-border merger resulted in the recognition of a net income tax provision of $4,266 , after considering tax benefits from the utilization of current and prior year French net operating losses. The Company was able to utilize $4,266 of French research and development tax credits to offset the remaining cost of the transaction. The Company also removed $111,495 of French net operating losses as the carryforward of these losses was contingent on receiving favorable consent from the French tax authority. The French net operating losses had a full valuation allowance, resulting in no impact to the income tax provision from their removal. 2017 Tax Cuts and Jobs Act On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act includes significant changes to the U.S. corporate income tax system including: a federal corporate rate reduction from 35% to 21%; limitations on the deductibility of interest expense and executive compensation; creation of the base erosion anti-abuse tax (“BEAT”), a new minimum tax. As a result of the Act being signed into law, the Company recognized a provisional charge of $3,513 in the fourth quarter of 2017 related to the re-measurement of its U.S. net deferred tax assets and certain unrecognized tax benefits based on the lower enacted corporate tax rates. A majority of the provisions in the Tax Act are effective January 1, 2018. In response to the Tax Act, the SEC staff issued guidance on accounting for the tax effects of the Tax Act. The guidance provides a one-year measurement period for companies to complete the accounting. We reflected the income tax effects of those aspects of the Tax Act for which the accounting is complete. To the extent our accounting for certain income tax effects of the Tax Act is incomplete but we are able to determine a reasonable estimate, we recorded a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. We have not completed our accounting for the income tax effects of certain elements of the Tax Act. Because of the complexity of the new BEAT rules, we are continuing to evaluate these provisions of the Tax Act and whether taxes due on future U.S. inclusions related to BEAT should be recorded as a current-period expense when incurred, or factored into the Company’s measurement of its deferred taxes. As a result, we have not included an estimate of the tax expense or benefit related to these items for the period ended December 31, 2017.

Post-Retirement Benefit Plans

Post-Retirement Benefit Plans	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Post-Retirement Benefits Plans	Post-Retirement Benefit Plans Post-Retirement Benefit Contributions to French Government Agencies The Company is required by French law for our French employees to deduct specific monthly payroll amounts to support post-retirement benefit programs sponsored by the relevant government agencies in France. As the ultimate obligation is maintained by the French government agencies, there is no additional liability recorded by the Company in connection with these plans. Expenses recognized for these plans were $123 in 2017 , $348 in 2016 , and $573 in 2015 . The 2017 pension expense does not include the retirement indemnity curtailment gain of $717 which was recorded in the third and fourth quarters of 2017 associated with the reduction of certain defined benefit retirement plan liabilities due to the reduction in force. See Note 15: Restructuring Costs for more discussion. Retirement Indemnity Obligation – France French law requires the Company to provide for the payment of a lump sum retirement indemnity to French employees based upon years of service and compensation at retirement. The retirement indemnity has been actuarially calculated on the assumption of voluntary retirement at a government-defined retirement age. Benefits do not vest prior to retirement. Any actuarial gains or losses are recognized in the Company’s consolidated statements of income (loss) in the periods in which they occur. The benefit obligation is calculated as the present value of estimated future benefits to be paid, using the following assumptions for the years ended December 31: Retirement Benefit Obligation Assumptions: 2017 2016 2015 Compensation rate increase 3.00 % 3.00 % 3.00 % Discount rate 1.25 % 1.31 % 2.03 % Employee turn-over Actuarial standard and average of the last 5 years Average age of retirement 60 to 65 years actuarial standard based on age and professional status Certain actuarial assumptions, such as discount rate, have a significant effect on the amounts reported for net periodic benefit cost and accrued retirement indemnity benefit obligation amounts. The discount rate is determined annually by benchmarking a published long-term bond index using the iBoxx € Corporates AA 10+ index. Changes in the funded status of the retirement indemnity benefit plans were as follows for the years ended December 31: Retirement Benefit Obligation Activity: 2017 2016 Retirement indemnity benefit obligation, beginning of year $ 2,431 $ 2,170 Service cost 132 123 Interest cost 21 29 Plan amendment (829 ) — Curtailment gain (717 ) — Actuarial (loss) gain (25 ) 203 Exchange rate changes 290 (94 ) Retirement indemnity benefit obligation, end of year $ 1,303 $ 2,431 The lump sum retirement indemnity is accrued on the Company’s consolidated balance sheets within non-current other liabilities, excluding the current portion. As these are not funded benefit plans, there are no respective assets recorded. The future expected benefits to be paid over the next five years and for the five years thereafter is as follows for the years ended December 31: Future Retirement Indemnity Benefit Obligation: Balance 2018 $ — 2019 12 2020 — 2021 — 2022 — Next five years 198 Total 210

Other Assets and Liabilities

Other Assets and Liabilities	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Other Assets and Liabilities	Other Assets and Liabilities Various other assets and liabilities are summarized for the years ended December 31, as follows: Prepaid Expenses and Other Current Assets: 2017 2016 Valued-added tax recoverable $ 1,206 $ 736 Prepaid expenses 7,106 3,442 Advance to suppliers and other current assets 128 1,265 Income tax receivable 518 451 Total $ 8,958 $ 5,894 Other Non-Current Assets: 2017 2016 Deferred tax assets $ 3,877 $ 7,432 Long-term deposit 3,350 — Other 3,022 99 Total $ 10,249 $ 7,531 Accrued Expenses: 2017 2016 Accrued compensation $ 3,157 $ 3,291 Accrued social charges 1,204 794 Accrued employee severance (see Note 15: Restructuring Costs ) 1,000 — Customer allowances 10,613 7,981 Accrued ELAA payment 20,000 — Accrued CMO charges 2,327 936 Accrued contract sales organization and marketing costs 7,641 — Other 4,984 4,220 Total $ 50,926 $ 17,222 Other Non-Current Liabilities: 2017 2016 Provision for retirement indemnity $ 1,303 $ 2,431 Customer allowances 1,636 905 Unrecognized tax benefits 3,954 1,565 Other 191 374 Total $ 7,084 $ 5,275

Contingent Liabilities and Comm

Contingent Liabilities and Commitments	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities and Commitments	Contingent Liabilities and Commitments Litigation The Company is subject to potential liabilities generally incidental to our business arising out of present and future lawsuits and claims related to product liability, personal injury, contract, commercial, intellectual property, tax, employment, compliance and other matters that arise in the ordinary course of business. The Company accrues for potential liabilities when it is probable that future costs (including legal fees and expenses) will be incurred and such costs can be reasonably estimated. At December 31, 2017 and December 31, 2016, there were no contingent liabilities with respect to any threat of litigation, arbitration or administrative or other proceeding that are reasonably likely to have a material adverse effect on the Company’s consolidated financial position, results of operations, cash flows or liquidity. Material Commitments At December 31, 2017, the Company has a commitment to purchase services for a total of $22,500 for a five-year period commencing January 1, 2015. The minimum amount of services for the remaining two years is $4,875 for both 2018 and 2019 . The Company also has two commitments to purchase finished product from two different contract manufacturers for a twenty-year period commencing August 1, 2015 and for a six-year period commencing in 2017. For the twenty-year commitment, the commitment for any individual year is contractually waived if the Company’s net customer sales for that product exceed certain amounts in that same year. This commitment, which amounts to $19,705, has been assumed by Cerecor as part of the divestiture of the pediatric assets. See Note 21: Subsequent Events. Commitments for these arrangements, at maximum quantities and at contractual prices over the remaining life of the contract, and excluding any waived commitments, are as follows for the years ended December 31: Purchase Commitments: Balance 2018 $ 10,512 2019 9,406 2020 4,531 2021 4,531 2022 4,531 Thereafter 14,169 Total $ 47,680 For the year ended December 31, 2017, the Company paid $6,898 related to the above purchase commitments. The Company and our subsidiaries lease office facilities under noncancelable operating leases expiring at various dates. Rent expense, net of rental income, was $1,146 , $970 and $752 in 2017, 2016, and 2015, respectively. Minimum rental commitments for non-cancelable leases in effect at December 31, 2017 are as follows: Lease Commitment: Balance 2018 $ 1,417 2019 919 2020 812 2021 548 2022 559 Thereafter 188 Total $ 4,443 Other than the above commitments, there were no other material commitments outside of the normal course of business. Material commitments in the normal course of business include long-term debt, long-term related party payable, and post-retirement benefit plan obligations which are disclosed in Note 9: Long-Term Debt, Note 10: Long-Term Related Party Payable, and Note 12: Post-Retirement Benefit Plans , respectively. Contractual Obligations The following table presents contractual obligations of the Company at December 31, 2017 : Payments Due by Period Contractual Obligations: Total Less than 1 to 3 3 to 5 More than Long-term debt $ 267 $ 111 $ 156 $ — $ — Long-term related party payable (1) 163,100 22,173 26,080 37,822 77,025 Purchase commitments (2) 47,680 10,512 13,937 9,062 14,169 Operating leases 4,957 1,721 1,912 1,136 188 Total contractual cash obligations $ 216,004 $ 34,517 $ 42,085 $ 48,020 $ 91,382 (1) On February 12, 2018, Avadel Pharmaceuticals plc (the “Company”), together with its subsidiaries Avadel Pharmaceuticals (USA), Inc., Avadel Pediatrics, Inc., FSC Therapeutics, LLC (“FSC Therapeutics”), and Avadel US Holdings, Inc. (“Holdings”), as the “Sellers,” entered into an asset purchase agreement (the “Purchase Agreement”) with Cerecor, Inc. (“Cerecor”). At the closing under the Purchase Agreement, on February 16, 2018, Cerecor purchased from the Sellers four pediatric commercial stage assets – Karbinal™ ER, Cefaclor, Flexichamber™ and AcipHex® Sprinkle™, together with certain associated business assets – which were held by FSC Therapeutics and FSC Laboratories, Inc., which is also a subsidiary of the Company (collectively “FSC”). The Company acquired FSC in February 2016 from Deerfield CSF, LLC (“Deerfield CSF”) and certain of its affiliates. Pursuant to the Purchase Agreement, Cerecor assumed the Company’s remaining payment obligations to Deerfield CSF under the Membership Interest Purchase Agreement dated February 5, 2016, between Holdings, Flamel Technologies SA (the predecessor of the Company) and Deerfield CSF and certain of its affiliates, which payment obligations consist of the following (collectively, the “Assumed Obligations”): (i) a quarterly payment of $263 beginning in July 2018 and ending in October 2020, amounting to an aggregate payment obligation of $2,625; (ii) a payment in January 2021 of $15,263; and (iii) a quarterly royalty payment of 15% on net sales of the FSC products through February 5, 2026 (“FSC Product Royalties”), in an aggregate amount of up to approximately $10,300. All three of these amounts, which total approximately $29,000, are included within the Long-term related party payable line above. See Note 21: Subsequent Events for a further discussion. (2) This line includes the twenty-year commitment, which amounts to $19,705 and has been assumed by Cerecor as part of the Purchase Agreement. See Note 21: Subsequent Events for a further discussion .

Restructuring Costs

Restructuring Costs	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Costs During the first quarter of 2017, the Company announced a plan to reduce our workforce at our Venniseux, France site by approximately 50% . This reduction is an effort to align the Company’s cost structure with our ongoing and future planned projects. In July 2017, the Company completed negotiations with the works council for our French operations and received approval from the French Labor Commission (DIRECCTE) to implement the plan. The reduction is substantially complete at December 31, 2017. Restructuring charges of $2,542 , which are net of the curtailment gain of $717 , were recognized during the year ended December 31, 2017 . No similar amounts were recorded during the prior year. The following table sets forth activities for the Company’s cost reduction plan obligations for the year ended December 31, 2017 : Severance Obligation: 2017 Balance of restructuring accrual at January 1, $ — Charges for employee severance, benefits and other 3,259 Payments (2,600 ) Foreign currency impact 341 Balance of restructuring accrual at December 31, $ 1,000 The restructuring accrual at December 31, 2017 is included the consolidated balance sheet in Accrued expenses.

Equity Instruments and Stock Ba

Equity Instruments and Stock Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Instruments and Stock Based Compensation	Equity Instruments and Stock-Based Compensation Capital Stock We have 500,000 shares of authorized ordinary shares with a nominal value of $0.01 per common share. As of December 31, 2017 , we had 41,463 and 39,346 shares of ordinary shares issued and outstanding, respectively. The Board of Directors is authorized to issue preferred shares in series, and with respect to each series, to fix its designation, relative rights (including voting, dividend, conversion, sinking fund, and redemption rights), preferences (including dividends and liquidation) and limitations. We have 50,000 shares of authorized preferred shares, $0.01 nominal value, no ne of which is currently outstanding. Share Repurchases In March 2017, the Board of Directors approved an authorization to repurchase up to $25,000 of Avadel ordinary shares represented by ADSs. Under this authorization, which has an indefinite duration, share repurchases may be made in the open market, in block transactions on or off the exchange, in privately negotiated transactions, or through other means as determined by the Board of Directors and in accordance with the regulations of the Securities and Exchange Commission. The timing and amount of repurchases, if any, will depend on a variety of factors, including the price of our shares, cash resources, alternative investment opportunities, corporate and regulatory requirements and market conditions. This share repurchase program may be modified, suspended or discontinued at any time without prior notice. We may also from time to time establish a trading plan under Rule 10b5-1 of the Securities and Exchange Act of 1934 to facilitate purchases of our shares under this program. As of December 31, 2017 , the Company had repurchased 2,117 ordinary shares for $22,361 . Additionally, on February 12, 2018, the Board of Directors approved an authorization to repurchase up to $20,000 of Avadel ordinary shares represented by American Depository Shares in connection with our Convertible Notes Offering completed on February 16, 2018. See Note 21: Subsequent Events . Stock-Based Compensation Compensation expense included in the Company’s consolidated statements of income (loss) for all stock-based compensation arrangements was as follows for the periods ended December 31: Stock-based Compensation Expense: 2017 2016 2015 Research and development $ 672 $ 3,523 $ 1,587 Selling, general and administrative 7,400 11,156 6,154 Total stock-based compensation expense $ 8,072 $ 14,679 $ 7,741 As of December 31, 2017 , the Company expects $13,101 of unrecognized expense related to granted, but non-vested stock-based compensation arrangements to be incurred in future periods. This expense is expected to be recognized over a weighted average period of 3.1 years. The excess tax benefit related to stock-based compensation recorded by the Company was not material in for the years ended December 31, 2017 and 2016 and $1,767 , for the year ended December 31, 2015 . Upon exercise of stock options or warrants, or upon the issuance of restricted share awards, the Company issues new shares. At December 31, 2017 , there were 2,290,147 shares authorized for stock option grants, warrant grants and restricted share award grants in subsequent periods. Determining the Fair Value of Stock Options and Warrants The Company measures the total fair value of stock options and warrants on the grant date using the Black-Scholes option-pricing model and recognizes each grant’s fair value as compensation expense over the period that the option or warrant vests. Options are granted to employees of the Company and become exercisable ratably over four years following the grant date and expire ten years after the grant date. Prior to 2017, warrants were typically issued to the Company’s Board of Directors as compensation for services rendered and generally become exercisable within one year following the grant date, and expire four years after the grant date. Beginning in 2017, the Company issues stock options to our Board of Directors as compensation for services rendered and generally become exercisable within one year following the grant date, and expire four years after the grant date. The weighted-average assumptions under the Black-Scholes option-pricing model for stock option and warrant grants as of December 31, 2017 , 2016 and 2015 , are as follows: Stock Option and Warrant Assumptions: 2017 2016 2015 Stock option grants: Expected term (years) 6.25 6.25 6.25 Expected volatility 58.82 % 58.39 % 58.59 % Risk-free interest rate 2.20 % 2.04 % 1.89 % Expected dividend yield — — — Warrant grants: Expected term (years) — 2.50 2.50 Expected volatility — % 60.57 % 55.00 % Risk-free interest rate — % 0.82 % 0.89 % Expected dividend yield — — — Expected term : The expected term of the options or warrants represents the period of time between the grant date and the time the options or warrants are either exercised or forfeited, including an estimate of future forfeitures for outstanding options or warrants. Given the limited historical data and the grant of stock options and warrants to a limited population, the simplified method has been used to calculate the expected life. Expected volatility : The expected volatility is calculated based on an average of the historical volatility of the Company’s stock price for a period approximating the expected term. Risk-free interest rate : The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant and a maturity that approximates the expected term. Expected dividend yield : The Company has not distributed any dividends since our inception, and has no plan to distribute dividends in the foreseeable future. Stock Options A summary of the combined stock option activity and other data for the Company’s stock option plans for the year ended December 31, 2017 is as follows: Stock Option Activity and Other Data: Number of Stock Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Stock options outstanding, January 1, 2017 3,732 $ 12.07 Granted 1,477 9.24 Exercised (14 ) 4.99 Forfeited (46 ) 12.88 Expired (108 ) 13.47 Stock options outstanding, December 31, 2017 5,041 $ 11.34 8.19 years $ 1,187 Stock options exercisable, December 31, 2017 1,917 $ 11.79 6.68 years $ 1,161 The aggregate intrinsic value of options exercised during the years ended December 31, 2017 , 2016 and 2015 was $1,161 , $58 , and $10,063 , respectively. The weighted average grant date fair value of options granted during the years ended December 31, 2017 , 2016 and 2015 was $9.24 , $6.14 and $9.38 per share, respectively. Warrants A summary of the combined warrant activity and other data for the year ended December 31, 2017 is as follows: Warrant Activity and Other Data: Number of Warrants Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Warrants outstanding, January 1, 2017 959 $ 16.05 Granted — — Exercised (55 ) 6.14 Forfeited — — Expired (10 ) 6.14 Warrants outstanding, December 31, 2017 894 $ 16.77 1.51 years $ — Warrants exercisable, December 31, 2017 894 $ 16.77 1.51 years $ — Each of the above warrants is convertible into one ordinary share. The aggregate intrinsic value of warrants exercised during the years ended December 31, 2017 , 2016 and 2015 was $0 , $0 and $2,698 , respectively. The weighted average grant date fair value of warrants granted during the years ended December 31, 2016 and 2015 was $2.99 and $5.92 per share, respectively. There were no warrants granted during the year ended December 31, 2017. At December 31, 2017 , an additional 3,300 warrants were outstanding and exercisable relative to consideration paid for the Company’s acquisition of Éclat Pharmaceuticals, LLC on March 13, 2012. These warrants are not considered stock-based compensation and are therefore excluded from the above tables, and instead are addressed within Note 10: Long-Term Related Party Payable . Restricted Share Awards Restricted share awards represent Company shares issued free of charge to employees of the Company as compensation for services rendered. The Company measures the total fair value of restricted share awards on the grant date using the Company’s stock price at the time of the grant. Restricted share awards granted prior to 2016 generally cliff vest at the end of a four -year vesting period, and are expensed over a two or four -year service period. Restricted share awards granted during and after 2016 are fully expensed at the date of grant as they contain no service requirement. Employees, however, are not free to trade these awards until the end of a two -year holding period. A summary of the Company’s restricted share awards as of December 31, 2017 , and changes during the year then ended, is reflected in the table below. Restricted Share Activity and Other Data: Number of Restricted Share Awards Weighted Average Grant Date Fair Value Non-vested restricted share awards outstanding, January 1, 2017 573 $ 12.57 Granted 271 8.95 Vested (23 ) 7.31 Forfeited (2 ) 16.27 Non-vested restricted share awards outstanding, December 31, 2017 819 $ 11.51 The weighted average grant date fair value of restricted share awards granted during the years ended December 31, 2017 and 2016 was $8.95 and $12.11 , respectively. There were no restricted share awards granted in 2015 . Employee Share Purchase Plan In 2017, the Board of Directors approved of the Avadel Pharmaceuticals plc 2017 Avadel Employee Share Purchase Plan (“ESPP”). The total number of Company ordinary shares, nominal value $0.01 per share, or ADSs representing such ordinary shares (collectively, “Shares”) which may be issued under the ESPP is 1,000 . The purchase price at which a Share will be issued or sold for a given offering period will be established by the Compensation Committee of the Board (“Committee”) (and may differ among participants, as determined by the Committee in its sole discretion) but will in no event be less than 85% of the lesser of: (a) the fair market value of a Share on the offering date; or (b) the fair market value of a Share on the purchase date. As of December 31, 2017, there were no shares issued to employees as the program was launched in January 2018.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Net Income (Loss) Per Share Basic net income (loss) per share is calculated using the weighted average number of shares outstanding during each period. The diluted net income (loss) per share calculation includes the impact of dilutive equity compensation awards and contingent consideration warrants. A reconciliation of basic and diluted net income (loss) per share, together with the related shares outstanding in thousands for the years ended December 31, is as follows: Net Income (Loss) Per Share: 2017 2016 2015 Net income (loss) $ 68,271 $ (41,276 ) $ 41,798 Weighted average shares: Basic shares 40,465 41,248 40,580 Effect of dilutive securities—options and warrants outstanding 1,300 — 3,039 Diluted shares 41,765 41,248 43,619 Net income (loss) per share - basic $ 1.69 $ (1.00 ) $ 1.03 Net income (loss) per share - diluted $ 1.63 $ (1.00 ) $ 0.96 Potential common shares of 6,368 , 8,564 , and 635 were excluded from the calculation of weighted average shares for the years ended December 31, 2017 , 2016 and 2015 , because their effect was considered to be anti-dilutive. For the year ended December 31, 2016 , the effects of dilutive securities were entirely excluded from the calculation of net income (loss) per share as a net loss was reported in this period.

Comprehensive Income (Loss)

Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Comprehensive Income (Loss)	Comprehensive Income (Loss) The following table shows the components of accumulated other comprehensive income (loss) for the twelve months ended December 31, net of immaterial tax effects: Accumulated Other Comprehensive Income (Loss): 2017 2016 2015 Foreign currency translation adjustment: Beginning balance $ (23,336 ) $ (22,312 ) $ (7,225 ) Net other comprehensive income (loss) 134 (1,024 ) (15,087 ) Balance at December 31, (23,202 ) (23,336 ) (22,312 ) Unrealized gain (loss) on marketable securities, net Beginning balance (229 ) (345 ) (198 ) Net other comprehensive income (loss), net of $28, $16, ($20), tax, respectively 165 116 (147 ) Balance at December 31, (64 ) (229 ) (345 ) Accumulated other comprehensive loss at December 31, $ (23,266 ) $ (23,565 ) $ (22,657 )

Company Operations by Product,

Company Operations by Product, Customer and Geographic Area	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Company Operations by Product, Customer and Geographic Area	Company Operations by Product, Customer and Geographic Area The Company has determined that we operate in one segment, the development and commercialization of pharmaceutical products, including controlled-release therapeutic products based on our proprietary polymer based technology. The Company’s Chief Operating Decision Maker is the CEO. The CEO and the Board review profit and loss information on a consolidated basis to assess performance and make overall operating decisions as well as resource allocations. All products are included in one segment because the Company’s products have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. The following table presents a summary of total revenues by these products for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Product: 2017 2016 2015 Bloxiverz $ 45,596 $ 82,896 $ 150,083 Vazculep 38,187 39,796 20,151 Akovaz 80,617 16,831 — Other 8,441 7,699 2,054 Total product sales and services 172,841 147,222 172,288 License and research revenue 404 3,024 721 Total revenue $ 173,245 $ 150,246 $ 173,009 Concentration of credit risk with respect to accounts receivable is limited due to the high credit quality comprising a significant portion of the Company’s customers. Management periodically monitors the creditworthiness of our customers and believes that we have adequately provided for any exposure to potential credit loss. The following table presents a summary of total revenues by significant customer for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Significant Customer: 2017 2016 2015 Customer A $ 53,342 $ 17,728 $ — Customer B 44,762 51,648 53,988 Customer C 37,965 39,359 60,420 Customer D 25,691 30,916 43,434 Others 11,081 7,571 14,446 Total product sales and services 172,841 147,222 172,288 License and research revenue 404 3,024 721 Total revenue $ 173,245 $ 150,246 $ 173,009 As of December 31, 2017 , the Company had three customers, each of which are substantial wholesale distributors, and accounted for 10% or more of the accounts receivable balance. One customer accounted for 31% , or $4,550 , a second customer accounted for 26% or $3,772 , and a third customer accounted for 23% or $3,395 . As of December 31, 2017 , the Company had no significant past due account receivable balances. The following table summarizes revenues by geographic region for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Geographic Region: 2017 2016 2015 United States $ 172,841 $ 147,283 $ 172,179 France — — 89 Ireland 404 2,963 741 Total revenues $ 173,245 $ 150,246 $ 173,009 Currently we depend on a single contract manufacturing organization for the manufacture of Bloxiverz, Vazculep and Akovaz, and to deliver certain raw materials used in their production, from which we derive a majority of our revenues. Additionally, we purchase certain raw materials used in our products from a limited number of suppliers, including a single supplier for certain key ingredients. Non-monetary long-lived assets primarily consist of property and equipment, goodwill and intangible assets. The following table summarizes non-monetary long-lived assets by geographic region as of December 31, 2017 , 2016 , and 2015 : Long-lived Assets by Geographic Region: 2017 2016 2015 United States $ 116,536 $ 42,021 $ 34,515 France 2,257 2,524 2,317 Ireland 1,360 202 258 Total $ 120,153 $ 44,747 $ 37,090

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In March 2012, the Company acquired all of the membership interests of Éclat from Breaking Stick Holdings, L.L.C. (“Breaking Stick”, formerly Éclat Holdings), an affiliate of Deerfield Capital L.P (“Deerfield”), a significant shareholder of the Company. As of December 31, 2016 and 2015, the remaining consideration obligations for this transaction consisted of two warrants to purchase a total of 3,300 shares of Avadel and commitments to make earnout payments to Breaking Stick of 20% of any gross profit generated by certain Éclat products (the “Products”). Breaking Stick is majority owned by Deerfield, with a minority interest owned by the Company’s CEO and certain other current and former employees. The Company entered into a Security Agreement dated March 13, 2012 with Breaking Stick, whereby Breaking Stick was granted a security interest in various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Breaking Stick under the Royalty Agreement. As part of a February 2013 debt financing transaction conducted with Deerfield Management, Éclat entered into a Royalty Agreement with Horizon Santé FLML, Sarl and Deerfield Private Design Fund II, L.P., both affiliates of the Deerfield Entities (together, “Deerfield PDF/Horizon”). The Royalty Agreement provides for the Company to pay Deerfield PDF/Horizon 1.75% of the net sales of the Products sold by the Company and any of our affiliates until December 31, 2024 , with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. The Company has also entered into a Security Agreement dated February 4, 2013 with Deerfield PDF/Horizon, whereby Deerfield PDF/Horizon was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Deerfield PDF/Horizon under the Royalty Agreement. As part of a December 2013 debt financing transaction conducted with Broadfin Healthcare Master Fund (“Broadfin”), the Company also entered into a Royalty Agreement with Broadfin, a significant shareholder of the Company, dated as of December 3, 2013 (the “Broadfin Royalty Agreement”). Pursuant to the Broadfin Royalty Agreement, the Company is required to pay a royalty of 0.834% on the net sales of certain products sold by the Company and any of our affiliates until December 31, 2024 with royalty payments paid in arrears for each calendar quarter during the term of the Royalty Agreement. The Company has also entered into a Security Agreement dated December 3, 2013 with Broadfin, whereby Broadfin was granted a security interest in the various tangible and intangible assets related to the Products to secure the obligations of Éclat and Avadel US Holdings, Inc., including the full and prompt payment of royalties to Broadfin under the Royalty Agreement. The Company entered into an agreement dated February 5, 2016 to acquire FSC Holdings, LLC (“FSC”), a specialty pharmaceutical company dedicated to providing innovative solutions to unmet medical needs for pediatric patients, from Deerfield CSF, LLC, a Deerfield Management company (“Deerfield”), a related party. Under the terms of the acquisition, which was completed on February 8, 2016, the Company will pay $1,050 annually for five years with a final payment in January 2021 of $15,000 for a total of $20,250 to Deerfield for all of the equity interests in FSC. The Company will also pay Deerfield a 15% royalty per annum on net sales of the current FSC products, up to $12,500 for a period not exceeding ten years. These obligations were assumed by Cerecor in connection with the divestiture of the Company’s pediatric products on February 16, 2018. See Note 21: Subsequent Events.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events Asset Purchase Agreement with Cerecor . On February 12, 2018, Avadel Pharmaceuticals plc (the “Company”), together with its subsidiaries Avadel Pharmaceuticals (USA), Inc., Avadel Pediatrics, Inc., FSC Therapeutics, LLC (“FSC Therapeutics”), and Avadel US Holdings, Inc. (“Holdings”), as the “Sellers,” entered into an asset purchase agreement (the “Purchase Agreement”) with Cerecor, Inc. (“Cerecor”). At the closing under the Purchase Agreement, on February 16, 2018, Cerecor purchased from the Sellers four pediatric commercial stage assets – Karbinal™ ER, Cefaclor, Flexichamber™ and AcipHex® Sprinkle™, together with certain associated business assets – which were held by FSC Therapeutics and FSC Laboratories, Inc., which is also a subsidiary of the Company (collectively “FSC”). The Company acquired FSC in February 2016 from Deerfield CSF, LLC (“Deerfield CSF”) and certain of its affiliates. Pursuant to the Purchase Agreement, Cerecor assumed the Company’s remaining payment obligations to Deerfield CSF under the Membership Interest Purchase Agreement, dated as of February 5, 2016, between Holdings, Flamel Technologies SA (the predecessor of the Company) and Deerfield CSF and certain of its affiliates, which payment obligations consist of the following (collectively, the “Assumed Obligations”): (i) a quarterly payment of $263 beginning in July 2018 and ending in October 2020, amounting to an aggregate payment obligation of $2,625; (ii) a payment in January 2021 of $15,263; and (iii) a quarterly royalty payment of 15% on net sales of the FSC products through February 5, 2026 (“FSC Product Royalties”), in an aggregate amount of up to approximately $10,300. Cerecor also assumed certain contracts and other obligations related to the acquired assets, and in that connection Holdings agreed to pay Cerecor certain make-whole payments associated with obligations Cerecor is assuming related to a certain supply contract related to Karbinal™ ER. License and Development Agreement Also in connection with the closing under the Purchase Agreement, Flamel Ireland Limited, an Irish limited company operating under the trade name of Avadel Ireland (“Avadel Ireland”) and a wholly-owned subsidiary of the Company, and Cerecor entered into a license and development agreement (the “License and Development Agreement”) pursuant to which, among other things: • Avadel Ireland will provide Cerecor with four product formulations utilizing Avadel Ireland’s LiquiTime™ technology, and will complete pilot bioequivalence studies for such product formulations within 18 months; • Cerecor will reimburse Avadel Ireland for development costs of the four LiquiTime™ products in excess of $1,000 in the aggregate; • Upon transfer of the four product formulations, Cerecor will assume all remaining development costs and responsibilities for the product development, clinical studies, NDA applications and associated filing fees; and • Upon regulatory approval and commercial launch of any LiquiTime™ products, Cerecor will pay Avadel Ireland quarterly royalties based on a percentage of net sales of any such products in the mid-single. Deerfield Guarantee In connection with the closing under the Purchase Agreement, the Company and Holdings provided their guarantee (the “Deerfield Guarantee”) in favor of Deerfield CSF, LLC and certain of its affiliates (“Deerfield”). Under the Deerfield Guarantee, the Company and Holdings guaranteed to Deerfield the payment by Cerecor of the obligations of the Company and certain of its subsidiaries (the “Assumed Obligations”) under the Membership Interest Purchase Agreement between the Company and Deerfield dated February 5, 2016. The Assumed Obligations include (i) a quarterly payment of $263 beginning in July 2018 and ending in October 2020, amounting to an aggregate payment obligation of $2,625; (ii) a payment in January 2021 of $15,263; and (iii) a quarterly royalty payment of 15% on net sales of the FSC products through February 6, 2026 (“FSC Product Royalties”), in an aggregate amount of up to approximately $10,300. In addition, under the Deerfield Guarantee, the Company and Holdings guaranteed that Deerfield would receive certain minimum annual FSC Product Royalties through February 6, 2026 (the “Minimum Royalties”). Armistice Guarantee In connection with the closing under the Purchase Agreement, Armistice Capital Master Fund, Ltd., the majority shareholder of Cerecor, guaranteed to Holdings the payment by Cerecor of the Assumed Obligations, including the Minimum Royalties. The fair values of the Avadel guarantee to Deerfield and the guarantee received by Avadel from Armistice largely offset and when combined are not material. The Company does not expect to record a significant gain or loss on the disposition of these assets. Issuance of Exchangeable Notes On February 14, 2018 we announced that our wholly-owned subsidiary, Avadel Finance Cayman Limited (the “Issuer”), priced a $125,000 aggregate principal amount of 4.50% exchangeable senior notes due 2023 (the “Notes”) in a private placement (the “Offering”) to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The sale of the Notes closed on February 16, 2018. In connection with the Offering, the Issuer granted the initial purchasers of the Notes a 30-day option to purchase up to an additional $18,750 aggregate principal amount of the Notes, which was fully exercised on February 16, 2018. Net proceeds from the Notes were $137,719 after deducting the initial purchasers’ discount and estimated offering expenses. We expect to use the net proceeds of the Offering for working capital and general corporate purposes. We also used cash on-hand to purchase approximately 2.0 million ADSs for $18,000 concurrently with the pricing of the Offering in privately negotiated transactions effected with or through a representative of the initial purchasers or an affiliate of such representative. The Issuer agreed to purchase such ADSs at a purchase price per ADS equal to the $8.99 per ADS closing price on The Nasdaq Global Market on February 13, 2018. The Notes are general, unsecured obligations of the Issuer, and are fully and unconditionally guaranteed by Avadel on a senior unsecured basis. Interest on the Notes will be payable semi-annually in cash in arrears on February 1 and August 1 of each year, beginning on August 1, 2018. The Notes will mature on February 1, 2023, unless earlier exchanged, repurchased or redeemed in accordance with their terms. The Notes will be issued in minimum denominations of $200 and integral multiples of $1 in excess thereof. Subject to certain conditions and during certain periods, the Notes will be exchangeable at the option of the holders at an initial exchange rate of 92.6956 ADSs per $1 principal amount of Notes, which is equivalent to an initial exchange price of approximately $10.79 per ADS. Such initial exchange price represents a premium of approximately 20% to the $8.99 per ADS closing price on The Nasdaq Global Market on February 13, 2018. Upon the exchange of any Notes, the Issuer will pay or cause to be delivered, as the case may be, cash, ADSs or a combination of cash and ADSs, at the Issuer’s election. The Company is evaluating the impacts of ASC 470-20 and the ASC 815 exception regarding conventional convertible notes that may be settled entirely or partially in cash upon conversion. Should these Notes be deemed as conventional per the exception allowed under ASC 815, the rules under ASC 470-20 would require the Company to separate the Notes into a liability and equity component, such that interest expense reflects our economic interest cost. The original issue discount would be recognized as a decrease in debt and an increase in equity. The debt component would accrete up to the principal amount over the expected term of the debt. In addition, under certain circumstances, convertible or exchangeable debt instruments that may be settled entirely or partly in cash are currently accounted for utilizing the treasury stock method, the effect of which is that the ADSs deliverable upon exchange of the Notes are not included in the calculation of diluted earnings per share except to the extent that the exchange value of the Notes exceeds their principal amount. Under the treasury stock method, for diluted earnings per share purposes, the transaction is accounted for as if the number of ADSs that would be necessary to settle such excess, if we elected to settle such excess in ADSs, are issued. Related Party Exercise of Warrants On February 22, 2018, the Company was notified by the related party holding 2,200 warrants ( See Note 10: Long-term Related Party Payable ) of its intent to exercise these warrants in full. As a result, the Company settled these warrants for a combination of cash of $2,911 and the issuance of approximately 603 ADS. The remaining 1,100 warrants held by this same related party, with an exercise price of $11.00 expired worthless on March 12, 2018.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure	Schedule II Valuation and Qualifying Accounts (In thousands) Deferred Tax Asset Valuation Allowance: Balance, Beginning of Period Additions (a) Deductions (b) Other Changes (c) Balance, End of Period 2017 $ 7,599 $ 391 $ (664 ) $ 8,028 $ 15,354 2016 $ 45,516 $ 6,873 $ (42,417 ) $ (2,373 ) 7,599 2015 57,980 4,312 (11,737 ) (5,039 ) 45,516 a. Additions to the deferred tax asset valuation allowance relate to movements on certain French, Irish and U.S. deferred tax assets where we continue to maintain a valuation allowance until sufficient positive evidence exists to support reversal. b. Deductions to the deferred tax asset valuation allowance include movements relating to utilization and removal of net operating losses and tax credit carryforwards, release in valuation allowance and other movements including adjustments following finalization of tax returns. c. Other changes to the deferred tax asset valuation allowance including currency translation adjustments recorded directly in equity and account method changes.

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations. Avadel Pharmaceuticals plc (“Avadel,” the “Company,” “we,” “our,” or “us”) is a branded specialty pharmaceutical company. Avadel’s current revenues are primarily derived from products we market based on first-to-file New Drug Applications (“NDAs”) for pharmaceutical products previously sold in the U.S. without FDA approval (“Unapproved Marketed Products” or “UMDs”). In addition, through the acquisition of patient-focused, innovative products or businesses in the commercial- and or late-stage of development, Avadel seeks to provide solutions for overlooked and unmet medical needs, including our urology product, Noctiva™, which we in-licensed in 2017 and will begin marketing in 2018. Avadel also seeks to develop products that utilize our Micropump® drug delivery technology, such as our narcolepsy product which is in clinical trials. Avadel’s current commercial portfolio consists of three sterile injectable products, which were previously UMDs, used in the hospital setting, and Noctiva™, a urology product, which is the first and only FDA approved product for the treatment of nocturia due to nocturnal polyuria in adults. Nocturia is the condition of waking two or more times per night to void. Avadel is actively developing a fourth sterile, injectable UMD product for which it expects to file an NDA and seek FDA approval. In addition, Avadel is currently enrolling patients in our REST-ON Phase III clinical trial to evaluate the safety and efficacy of FT 218, a once-nightly formulation of sodium oxybate using Micropump®, for the treatment of EDS and cataplexy in patients suffering from narcolepsy. Narcolepsy is a rare sleep disorder with few approved treatment options. Avadel will continue to strategically evaluate potential UMDs and Micropump® based product candidates for development and approval, and will also look for synergistic acquisition targets to grow our company. The Company was incorporated in Ireland on December 1, 2015 as a private limited company, and re-registered as an Irish public limited company on November 21, 2016. Our headquarters are in Dublin, Ireland and we have operations in St. Louis, Missouri, United States, and Lyon, France. The Company is an Irish public limited company, or plc, and is the successor to Flamel Technologies S.A., a French société anonyme (“Flamel”), as the result of the merger of Flamel with and into the Company which was completed at 11:59:59 p.m., Central Europe Time, on December 31, 2016 (the “Merger”) pursuant to the agreement between Flamel and Avadel entitled Common Draft Terms of Cross-Border Merger dated as of June 29, 2016 (the “Merger Agreement”). Immediately prior to the Merger, the Company was a wholly owned subsidiary of Flamel. As a result of the Merger Agreement: • Flamel ceased to exist as a separate entity and the Company continued as the surviving entity and assumed all of the assets and liabilities of Flamel. • our authorized share capital is $5,500 divided into 500,000 ordinary shares with a nominal value of $0.01 each and 50,000 preferred shares with a nominal value of $0.01 each ◦ all outstanding ordinary shares of Flamel, €0.122 nominal value per share, were canceled and exchanged on a one-for-one basis for newly issued ordinary shares of the Company, $0.01 nominal value per share. This change in nominal value of our outstanding shares resulted in our reclassifying $5,937 on our balance sheet from ordinary shares to additional paid-in capital ◦ our Board of Directors is authorized to issue preferred shares on a non-pre-emptive basis, for a maximum period of five years, at which point such an authorization may be renewed by shareholders. The Board of Directors has discretion to dictate terms attached to the preferred shares, including voting, dividend, conversion rights, and priority relative to other classes of shares with respect to dividends and upon a liquidation. • all outstanding American Depositary Shares (ADSs) representing ordinary shares of Flamel were canceled and exchanged on a one-for-one basis for ADSs representing ordinary shares of the Company. Thus, the Merger changed the jurisdiction of our incorporation from France to Ireland, and an ordinary share of the Company held (either directly or represented by an ADS) immediately after the Merger continued to represent the same proportional interest in our equity owned by the holder of a share of Flamel immediately prior to the Merger. Prior to completion of the Merger, the Flamel ADSs were listed on the Nasdaq Global Market (“Nasdaq”) under the trading symbol “FLML”; and immediately after the Merger the Company’s ADSs were listed for and began trading on Nasdaq on January 3, 2017 under the trading symbol “AVDL.” Further details about the reincorporation, the Merger and the Merger Agreement are contained in our definitive proxy statement filed with the Securities and Exchange Commission on May 1, 2017. Under Irish law, the Company can only pay dividends and repurchase shares out of distributable reserves, as discussed further in the Company’s proxy statement filed with the SEC as of July 5, 2016. Upon completion of the Merger, the Company did not have any distributable reserves. On February 15, 2017, the Company filed a petition with the High Court of Ireland seeking the court’s confirmation of a reduction of the Company’s share premium so that it can be treated as distributable reserves for the purposes of Irish law. On March 6, 2017, the High Court issued its order approving the reduction of the Company’s share premium by $317,254 which can be treated as distributable reserves.
Basis of Presentation	Basis of Presentation. These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP). The consolidated financial statements include the accounts of the Company and all subsidiaries. All intercompany accounts and transactions have been eliminated.
Revenue	Revenue. Revenue includes sales of pharmaceutical products, amortization of licensing fees, and, if any, milestone payments for R&D achievements. Product Sales and Services Revenue is generally realized or realizable and earned when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller’s price to the buyer is fixed or determinable, and collectability is reasonably assured. The Company records revenue from product sales when title and risk of ownership have been transferred to the customer, which is typically upon delivery to the customer and when the selling price is determinable. As is customary in the pharmaceutical industry, the Company’s gross product sales are subject to a variety of deductions in arriving at reported net product sales. These adjustments include estimates for product returns, chargebacks, payment discounts, rebates, and other sales allowances and are estimated based on analysis of historical data for the product or comparable products, as well as future expectations for such products. For generic products and branded products where the ultimate net selling price to customer is estimable, the Company recognizes revenues upon delivery to the wholesaler. For new product launches the Company recognizes revenue if sufficient data is available to determine product acceptance in the marketplace such that product returns may be estimated based on historical or analog product data and there is probable evidence of reorders and consideration is made of wholesaler inventory levels. As part of the third quarter 2016 launch of Akovaz, the Company determined that sufficient data was available to determine the ultimate net selling price to the customer and therefore recognized revenue upon delivery to our wholesaler customers. Prior to the second quarter 2016, the Company did not have sufficient historical or analog product data to estimate certain revenue deductions. As such, we could not accurately estimate the ultimate net selling price of our hospital portfolio of products and as a result delayed revenue recognition until the wholesaler sold the product through to end customers. During the second quarter of 2016, it was determined that we now had sufficient evidence, history, data and internal controls to estimate the ultimate selling price of our products upon shipment from our warehouse to our customers, the wholesalers. Accordingly, we discontinued the sell-through revenue approach and now recognize revenue once the product is delivered to the wholesaler. As a result of this change in accounting estimate, we recognized $5,981 in additional revenue, or $0.05 per diluted share, for the twelve months ended December 31, 2016 that previously would have been deferred until sold by the wholesalers to the hospitals. License and Research Revenue Our license and research revenues consist of fees and/or milestone payments. Non-refundable fees where we have continuing performance obligations are deferred and are recognized ratably over our projected performance period. We recognize milestone payments, which are typically related to regulatory, commercial or other achievements by us or our licensees and distributors, as revenues when the milestone is accomplished and collection is reasonably assured. To the extent that the expected timelines for such milestone payments are changed from initial estimates, the Company will record cumulative adjustments to reflect the revised timeline. For the year ended December 31, 2017, we recognized $404 of revenue from license agreements.
Governmental Grants	Government Grants. The Company receives financial support for various research or investment projects from governmental agencies. From time to time we receive funds, primarily from the French government, to finance certain R&D projects. These funds are repayable on commercial success of the project. In the absence of commercial success, the Company is released of our obligation to repay the funds and as such the funds are recognized in the consolidated statements of income (loss) as an offset to R&D expense. The absence of commercial success must be formally confirmed by the granting authority. Should the Company wish to discontinue the R&D to which the funding is associated, the granting authority must be informed and a determination made as to how much, if any, of the grant must be repaid.
Research and Development	Research and Development. R&D expenses consist primarily of costs related to clinical studies and outside services, personnel expenses, and other R&D expenses. Clinical studies and outside services costs relate primarily to services performed by clinical research organizations and related clinical or development manufacturing costs, materials and supplies, filing fees, regulatory support, and other third-party fees. Personnel expenses relate primarily to salaries, benefits and stock-based compensation. Other R&D expenses primarily include overhead allocations consisting of various support and facilities-related costs. R&D expenditures are charged to operations as incurred. The Company recognizes R&D tax credits received from the French government for spending on innovative R&D as an offset of R&D expenses.
Stock-based Compensation	Stock-based Compensation. The Company accounts for stock-based compensation based on grant-date fair value estimated in accordance with ASC 718. The fair value of stock options and warrants is estimated using Black-Scholes option-pricing valuation models (“Black-Scholes model”). As required by the Black-Sholes model, estimates are made of the underlying volatility of AVDL stock, a risk-free rate and an expected term of the option or warrant. We estimated the expected term using a simplified method, as we do not have enough historical exercise data for a majority of such options and warrants upon which to estimate an expected term. The Company recognizes compensation cost, net of an estimated forfeiture rate, using the accelerated method over the requisite service period of the award.
Income Taxes	Income Taxes. We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine deferred tax assets and liabilities on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. We record uncertain tax positions in accordance with ASC 740 on the basis of a two-step process in which (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. We recognize interest and penalties related to unrecognized tax benefits in the income tax expense line in the accompanying consolidated statements of income (loss). Accrued interest and penalties are included on the related tax liability line in the consolidated balance sheets.
Cash and Cash Equivalents	Cash and Cash Equivalents. Cash and cash equivalents consist of cash on hand, cash on deposit and fixed term deposits which are highly liquid investments with original maturities of less than three months.
Marketable Securities	Marketable Securities. The Company’s marketable securities are considered to be available for sale and are carried at fair value, with unrealized gains and losses, net of taxes, reported as a component of accumulated other comprehensive income (“AOCI”) in shareholders’ equity, with the exception of unrealized losses believed to be other-than-temporary, if any, which are reported in earnings in the current period. The cost of securities sold is based upon the specific identification method.
Accounts Receivables	Accounts Receivable. Accounts receivable are stated at amounts invoiced net of allowances for doubtful accounts and certain other gross to net deductions. The Company makes judgments as to our ability to collect outstanding receivables and provides allowances for the portion of receivables deemed uncollectible. Provision is made based upon a specific review of all significant outstanding invoices. A majority of accounts receivable is due from three significant customers. See Note 19: Company Operations by Product, Customer and Geographic Area.
Inventories	Inventories. Inventories consist of raw materials and finished products, which are stated at lower of cost or market determined under the first-in, first-out (“FIFO”) method. Raw materials used in the production of pre-clinical and clinical products are expensed as R&D costs when consumed. The Company establishes reserves for inventory estimated to be obsolete, unmarketable or slow-moving on a case by case basis.
Property and Equipment	Property and Equipment. Property and equipment is stated at historical cost less accumulated depreciation. Depreciation and amortization are computed using the straight-line method over the following estimated useful lives: Laboratory equipment 4-8 years Software, office and computer equipment 3 years Leasehold improvements, furniture, fixtures and fittings 5-10 years
Goodwill	Goodwill. Goodwill represents the excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed. The Company has determined that we operate in a single segment and has a single reporting unit associated with the development and commercialization of pharmaceutical products. The annual test for goodwill impairment is a two-step process. The first step is a comparison of the fair value of the reporting unit with its carrying amount, including goodwill. If this step indicates impairment, then, in the second step, the loss is measured as the excess of recorded goodwill over the implied fair value of the goodwill. Implied fair value of goodwill is the excess of the fair value of the reporting unit as a whole over the fair value of all separately identified assets and liabilities within the reporting unit. The Company tests goodwill for impairment annually and when events or changes in circumstances indicate that the carrying value may not be recoverable. During the fourth quarter of 2017, we performed our required annual impairment test of goodwill and have determined that no impairment of goodwill existed at December 31, 2017 or 2016.
Long-Lived Assets	Long-Lived Assets. Long-lived assets include fixed assets and intangible assets. Intangible assets consist primarily of purchased licenses and intangible assets recognized as part of the Éclat and FSC acquisitions. Acquired IPR&D has an indefinite life and is not amortized until completion and development of the project, at which time the IPR&D becomes an amortizable asset, for which amortization of such intangible assets is computed using the straight-line method over the estimated useful life of the assets. Long-lived assets are reviewed for impairment whenever conditions indicate that the carrying value of the assets may not be fully recoverable. Such impairment tests are based on a comparison of the pretax undiscounted cash flows expected to be generated by the asset to the recorded value of the asset or other market based value approaches. If impairment is indicated, the asset value is written down to its market value if readily determinable or its estimated fair value based on discounted cash flows. Any significant changes in business or market conditions that vary from current expectations could have an impact on the fair value of these assets and any potential associated impairment. The Company has determined that no impairment existed at December 31, 2017 or 2016.
Acquisition-related Contingent Consideration	Acquisition-related Contingent Consideration. The acquisition-related contingent consideration payables arising from the acquisition of Éclat Pharmaceuticals (i.e., our hospital products) and FSC (our pediatrics products) are accounted for at fair-value (see Item 8. Financial Statements and Supplementary Data and Note 10: Long-Term Related Party Payable ). The fair value of the warrants issued in connection with the Éclat acquisition are estimated using a Black-Scholes option pricing model. The fair value of acquisition-related contingent consideration payable is estimated using a discounted cash flow model based on the long-term sales or gross profit forecasts of the specified hospital or pediatric products using an appropriate discount rate. There are a number of estimates used when determining the fair value of these earn-out payments. These estimates include, but are not limited to, the long-term pricing environment, market size, market share the related products are forecast to achieve, the cost of goods related to such products and an appropriate discount rate to use when present valuing the related cash flows. These estimates can and often do change based on changes in current market conditions, competition, management judgment and other factors. Changes to these estimates can have and have had a material impact on our consolidated statements of income (loss) and balance sheets. Changes in fair value of these liabilities are recorded in the consolidated statements of income (loss) within operating expenses as changes in fair value of related party contingent consideration.
Financing-related Royalty Agreements	Financing-related Royalty Agreements. We also entered into two royalty agreements with related parties in connection with certain financing arrangements. We elected the fair value option for the measurement of the financing-related contingent consideration payable associated with the royalty agreements with certain Deerfield and Broadfin entities, both of whom are related parties (see Note 10: Long-Term Related Party Payable ). The fair value of financing-related royalty agreements is estimated using the same components used to determine the fair value of the acquisition-related contingent consideration noted above, with the exception of cost of products sold. Changes to these components can also have a material impact on our consolidated statements of income (loss) and balance sheets. Changes in the fair value of this liability are recorded in the consolidated statements of income (loss) as other income (expense) - changes in fair value of related party payable.
Foreign Currency Translation	Foreign Currency Translation. At December 31, 2017, the reporting currency of the Company and our wholly-owned subsidiaries is the U.S. dollar. Prior to December 31, 2016, each of the Company’s non-U.S. subsidiaries and the parent entity, Flamel, used the Euro as their functional currency. At December 31, 2016, in conjunction with the Merger described above, Avadel determined the U.S. dollar is our functional currency. Subsidiaries and entities that do not use the U.S. dollar as their functional currency translate 1) profit and loss accounts at the average exchange rates during the reporting period, 2) assets and liabilities at period end exchange rates and 3) shareholders’ equity accounts at historical rates. Resulting translation gains and losses are included as a separate component of shareholders’ equity in accumulated other comprehensive loss. Assets and liabilities, excluding available-for-sale marketable securities, denominated in a currency other than the subsidiary’s functional currency are translated to the subsidiary’s functional currency at period end exchange rates with resulting gains and losses recognized in the consolidated statements of income (loss). Available-for-sale marketable securities denominated in a currency other than the subsidiary’s functional currency are translated to the subsidiary’s functional currency at period end exchange rates with resulting gains and losses recognized in the consolidated statements of comprehensive income (loss).
Use of Estimates	Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, including marketable securities and contingent liabilities at the date of the consolidated financial statements and the reported amounts of sales and expenses during the periods presented. These estimates and assumptions are based on the best information available to management at the balance sheet dates and depending on the nature of the estimate can require significant judgments. Changes to these estimates and judgments can have and have had a material impact on our consolidated statements of income (loss) and balance sheets. Actual results could differ from those estimates under different assumptions or conditions.
Effect of New Accounting Standards	In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2017-07, “ Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Costs .” The standard requires the service component of pension and other postretirement benefit expense to be presented in the same statement of income lines as other employee compensation costs, however, the other components will be presented outside of operating income. In addition, only the service cost component will be eligible for capitalization in assets. The standard is effective starting in 2018, with early adoption permitted. Retrospective application is required for the guidance on the statement of income presentation. Prospective application is required for the guidance on the cost capitalization in assets. The Company does not believe this standard will materially impact our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, “ Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment.” This update eliminates step 2 from the goodwill impairment test, and requires the goodwill impairment test to be performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This guidance is effective for the Company in the first quarter of 2020. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company will assess the timing of adoption and impact of this guidance to future impairment considerations. In January 2017, the FASB issued ASU 2017-01, “ Business Combinations (Topic 805): Clarifying the Definition of a Business .” This update provides a screen to determine whether or not a set of assets is a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set of assets is not a business. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set of assets must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. This guidance is effective for the Company in the first quarter of fiscal 2018. Early adoption is permitted for transactions not previously reported in the Company’s consolidated financial statements. In September 2017, the Company entered into an Exclusive License and Assignment Agreement (“ELAA”) to acquire from Serenity Pharmaceuticals, LLC intellectual property rights to further develop and commercialize Noctiva in the United States. The Company elected to early adopt ASU 2017-01 and determined the intangible assets acquired as part of the ELAA should be accounted for as an acquisition of a single group of assets and not as a business combination. In October 2016, the FASB issued ASU 2016-16, “ Income Taxes (Topic 740), Intra-Entity Transfers of Assets Other Than Inventory ,” which requires companies to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 is effective for annual reporting periods, and interim periods therein, beginning after December 15, 2017. The Company elected to early adopt ASU 2016-16 on a modified-retrospective basis as of January 1, 2017. Adoption of ASU 2016-16 eliminated the $11,156 income tax deferred charge recorded within the consolidated balance sheet as of December 31, 2016 and such elimination is reflected as an adjustment to accumulated deficit as of January 1, 2017. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments .” ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for the Company for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. ASU 2016-15 should be applied retrospectively and early adoption is permitted, including adoption in an interim period. The Company does not believe this standard will materially impact our consolidated financial statements. In May 2014, the FASB issued ASU 2014-09 “ Revenue from Contracts with Customers” which supersedes the most current revenue recognition requirements. This ASU requires entities to recognize revenue in a way that depicts the transfer of goods or services to customers in an amount that reflects the consideration which the entity expects to be entitled to in exchange for those goods or services. Through May 2016, the FASB issued ASU 2016-08 “ Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” ASU 2016-10 “ Identifying Performance Obligations and Licensing,” and ASU 2016-12, “ Narrow-Scope Improvements and Practical Expedients,” which provide supplemental adoption guidance and clarification to ASU 2014-09, respectively. These ASUs will be effective for annual and interim periods beginning after December 15, 2017, with early adoption for annual and interim periods beginning after December 15, 2016 permitted and should be applied retrospectively to each prior reporting period presented or as a modified retrospective adjustment as of the date of adoption. The Company has completed our evaluation and assessment of the potential impacts of adopting this pronouncement on our consolidated financial statements and related disclosures. Based on this assessment, we will adopt the pronouncement under the modified retrospective method of transition in the first quarter of 2018. The Company does not expect adoption of the new standard will have a material effect on the overall timing or amount of revenue recognized when compared to current accounting standards. The impact to the Company of adopting the new revenue standard primarily relates to additional and expanded disclosures. In March 2016, the FASB issued ASU 2016-09, “ Improvements to Employee Share-Based Payment Accounting ” which amends Accounting Standards Codification (“ASC”) Topic 718 “Compensation – Stock Compensation”. This update simplifies several aspects of accounting for share-based payment awards to employees, including the accounting for income taxes, classification of awards as either equity or liabilities, forfeitures and classification in the statement of cash flows. We adopted the standard on a prospective basis with the effect of adoption reflected for the interim periods after the year beginning January 1, 2017 as required by the standard. The primary effects of adoption were immaterial to the Company’s consolidated financial statements for the year ended December 31, 2017. In February 2016, the FASB issued ASU 2016-02, “ Leases ” which supersedes ASC 840 “ Leases ” and creates a new topic, ASC 842 “ Leases .” This update requires lessees to recognize on their balance sheet a lease liability and a lease asset for all leases, including operating leases, with a term greater than 12 months. The update also expands the required quantitative and qualitative disclosures surrounding leases. This update is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years, with earlier application permitted. This update will be applied using a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The Company is currently evaluating the effect of this update on our consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities .” The amendments in this update address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2017, and requires a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. Early adoption is not permitted. The new guidance will require the change in fair value of equity investments with readily determinable fair values to be recognized through the statement of income. Upon adoption, the change in the fair value of our available-for-sale equity investments will be recognized in our consolidated statement of income (loss) rather than as a component of our consolidated statement of comprehensive income (loss).

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Property and Equipment Useful Life	Property and equipment is stated at historical cost less accumulated depreciation. Depreciation and amortization are computed using the straight-line method over the following estimated useful lives: Laboratory equipment 4-8 years Software, office and computer equipment 3 years Leasehold improvements, furniture, fixtures and fittings 5-10 years The principal categories of property and equipment, net at December 31, 2017 and 2016 , respectively, are as follows: Property and Equipment, net: 2017 2016 Laboratory equipment $ 10,135 $ 9,019 Software, office and computer equipment 3,115 2,519 Furniture, fixtures and fittings 4,779 4,239 Less - accumulated depreciation (15,028 ) (12,457 ) Total $ 3,001 $ 3,320

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table summarizes the financial instruments measured at fair value on a recurring basis classified in the fair value hierarchy (Level 1, 2 or 3) based on the inputs used for valuation in the accompanying consolidated balance sheets: As of December 31, 2017 As of December 31, 2016 Fair Value Measurements: Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Marketable securities (see Note 4: Marketable Securities ) Equity securities $ 468 $ — $ — $ 4,033 $ — $ — Money market funds 44,481 — — — — — Corporate bonds — 9,262 — — 57,348 — Government securities - U.S. — 19,050 — — 42,814 — Government securities - Non-U.S. — — — — 233 — Other fixed-income securities — 4,250 — — 10,471 — Other securities — — — — 81 — Total assets $ 44,949 $ 32,562 $ — $ 4,033 $ 110,947 $ — Related party payable (see Note 10: Long-Term Related Party Payable ) — — 98,925 — — 169,347 Total liabilities $ — $ — $ 98,925 $ — $ — $ 169,347

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities	The following tables show the Company’s available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category as of December 31, 2017 and 2016 , respectively: 2017 Marketable Securities: Adjusted Cost Unrealized Gains Unrealized Losses Fair Value Equity securities $ 443 $ 31 $ (6 ) $ 468 Money market funds 44,525 — (44 ) 44,481 Corporate bonds 9,285 1 (24 ) 9,262 Government securities - U.S. 19,080 — (30 ) 19,050 Other fixed-income securities 4,259 — (9 ) 4,250 Total $ 77,592 $ 32 $ (113 ) $ 77,511 2016 Marketable Securities: Adjusted Cost Unrealized Gains Unrealized Losses Fair Value Equity securities $ 3,689 $ 409 $ (65 ) $ 4,033 Corporate bonds 57,871 89 (612 ) 57,348 Government securities - U.S. 43,049 515 (750 ) 42,814 Government securities - Non-U.S. 247 — (14 ) 233 Other fixed-income securities 10,281 221 (31 ) 10,471 Other securities 81 — — 81 Total $ 115,218 $ 1,234 $ (1,472 ) $ 114,980
Investments Classified by Contractual Maturity Date	The following table summarizes the estimated fair value of our investments in marketable debt securities, accounted for as available-for-sale securities and classified by the contractual maturity date of the securities as of December 31, 2017 : Maturities Marketable Debt Securities: Less than 1 Year 1-5 Years 5-10 Years Greater than 10 Years Total Corporate bonds 1,033 6,826 1,403 — 9,262 Government securities - U.S. 50 17,509 977 514 19,050 Other fixed-income securities — 4,250 — — 4,250 Total $ 1,083 $ 28,585 $ 2,380 $ 514 $ 32,562

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory	The principal categories of inventories, net reserves of $1,039 and $3,223 at December 31, 2017 and 2016 , respectively, are comprised of the following: Inventory: 2017 2016 Finished goods $ 4,774 $ 2,429 Raw materials 1,383 829 Total $ 6,157 $ 3,258

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment is stated at historical cost less accumulated depreciation. Depreciation and amortization are computed using the straight-line method over the following estimated useful lives: Laboratory equipment 4-8 years Software, office and computer equipment 3 years Leasehold improvements, furniture, fixtures and fittings 5-10 years The principal categories of property and equipment, net at December 31, 2017 and 2016 , respectively, are as follows: Property and Equipment, net: 2017 2016 Laboratory equipment $ 10,135 $ 9,019 Software, office and computer equipment 3,115 2,519 Furniture, fixtures and fittings 4,779 4,239 Less - accumulated depreciation (15,028 ) (12,457 ) Total $ 3,001 $ 3,320

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The fair values assigned to the acquired assets and liabilities have been recognized as follows: Assigned Fair Value: Amount Accounts receivable $ 142 Inventories 1,135 Prepaid expenses and other current assets 1,712 Intangible assets: Acquired product marketing rights 16,600 Acquired developed technology 4,300 Deferred tax assets 853 Other assets 277 Accounts payable and other liabilities (3,827 ) Total $ 21,192
Business Acquisition, Pro Forma Information	Had the FSC acquisition been completed as of the beginning of 2015, the Company’s unaudited pro forma net revenue and net income (loss) for the twelve months ended December 31, 2016 and 2015 would have been as follows: Pro Forma Net Revenue and Income (Loss): 2016 2015 Net revenues $ 150,721 $ 178,104 Net income (loss) (42,290 ) 30,965

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	The Company’s amortizable and unamortizable intangible assets at December 31, 2017 and 2016 , respectively, are as follows: 2017 2016 Goodwill and Intangible Assets: Gross Value Accumulated Amortization Net Carrying Amount Gross Value Accumulated Amortization Net Carrying Amount Amortizable intangible assets: Acquired developed technology - Noctiva $ 73,111 $ (1,401 ) $ 71,710 $ — $ — $ — Acquired developed technology - Vazculep 12,061 (9,616 ) 2,445 12,061 (8,801 ) 3,260 Acquired product marketing rights 16,600 (2,132 ) 14,468 16,600 (1,019 ) 15,581 Acquired developed technology 4,300 (634 ) 3,666 4,300 (304 ) 3,996 Total amortizable intangible assets $ 106,072 $ (13,783 ) $ 92,289 $ 32,961 $ (10,124 ) $ 22,837 Unamortizable intangible assets: Goodwill $ 18,491 $ — $ 18,491 $ 18,491 $ — $ 18,491 Total unamortizable intangible assets $ 18,491 $ — $ 18,491 $ 18,491 $ — $ 18,491
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	At December 31, 2017, total future amortization of intangible assets for the next five years is as follows: Estimated Amortization Expense: Amount 2018 $ 7,882 2019 7,882 2020 7,882 2021 7,067 2022 7,067

Long-Term Related Party Payab39

Long-Term Related Party Payable (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Related Party Transactions	(b) In March 2012, the Company acquired all of the membership interests of Éclat from Breaking Stick Holdings, L.L.C. (“Breaking Stick”, formerly Éclat Holdings), an affiliate of Deerfield. Breaking Stick is majority owned by Deerfield, with a minority interest owned by the Company’s CEO, and certain other current and former employees. As part of the consideration, the Company committed to provide quarterly earn-out payments equal to 20% of any gross profit generated by certain Éclat products. These payments will continue in perpetuity, to the extent gross profit of the related products also continue in perpetuity. (c) In February 2016, the Company acquired all of the membership interests of FSC from Deerfield. The consideration for this transaction in part included a commitment to pay quarterly a 15% royalty on the net sales of certain FSC products, up to $12,500 for a period not exceeding ten years. This obligation was assumed by the buyer as part of the disposition of the pediatrics products on February 16, 2018. See Note 21: Subsequent Events. (d) As part of a February 2013 debt financing transaction conducted with Deerfield, the Company received cash of $2,600 in exchange for entering into a royalty agreement whereby the Company shall pay quarterly a 1.75% royalty on the net sales of certain Éclat products until December 31, 2024. In connection with such debt financing transaction, the Company granted Deerfield a security interest in the product registration rights of the Eclat products. (e) As part of a December 2013 debt financing transaction conducted with Broadfin Healthcare Master Fund, a related party and current shareholder, the Company received cash of $2,200 in exchange for entering into a royalty agreement whereby the Company shall pay quarterly a 0.834% royalty on the net sales of certain Éclat products until December 31, 2024. (f) In February 2016, the Company acquired all of the membership interests of FSC from Deerfield. The consideration for this transaction in part consists of payments totaling $1,050 annually for five years with a final payment in January 2021 of $15,000 . Substantially all of FSC’s, and its subsidiaries, assets are pledged as collateral under this agreement. This obligation was assumed by the buyer as part of the disposition of the pediatrics products on February 16, 2018. See Note 21: Subsequent Events. Long-term related party payable and related activity are reported at fair value and consist of the following at December 31, 2017 and 2016 , respectively: Activity during the Twelve Months Ended December 31, 2017 Changes in Fair Value of Related Party Payable Balance, December 31, 2016 Payments to Related Parties Operating Income Other Income Balance, Acquisition-related contingent consideration: Warrants - Éclat Pharmaceuticals (a) $ 11,217 $ — $ (8,738 ) $ — $ 2,479 Earn-out payments - Éclat Pharmaceuticals (b) 121,377 (31,636 ) (21,997 ) — 67,744 Royalty agreement - FSC (c) 7,291 (1,246 ) (305 ) — 5,740 Financing-related: — Royalty agreement - Deerfield (d) 9,794 (2,999 ) — (1,403 ) 5,392 Royalty agreement - Broadfin (e) 4,668 (1,430 ) — (668 ) 2,570 Long-term liability - FSC (f) 15,000 — — — 15,000 Total related party payable 169,347 $ (37,311 ) $ (31,040 ) $ (2,071 ) 98,925 Less: Current portion (34,177 ) (25,007 ) Total long-term related party payable $ 135,170 $ 73,918 Each of the above items is associated with related parties as further described in Note 20: Related Party Transactions. (a) As part of the consideration for the Company’s acquisition of Éclat Pharmaceuticals, LLC on March 13, 2012, the Company issued two warrants to a related party with a six -year term which allow for the purchase of a combined total of 3,300 ordinary shares of Avadel. One warrant is exercisable for 2,200 ordinary shares at an exercise price of $7.44 per share, and the other warrant is exercisable for 1,100 ordinary shares at an exercise price of $11.00 per share. On February 23, 2018, the related party exercised in full the warrant for 2,200 ordinary shares. On March 12, 2018, the remaining warrant for 1,100 ordinary shares expired worthless. See Note 21: Subsequent Events . The following table summarizes changes to the related party payables, a recurring Level 3 measurement, for the twelve-month periods ended December 31, 2017 , 2016 and 2015 : Related Party Payable: Balance Balance at December 31, 2014 114,750 Payment of related party payable (27,897 ) Fair value adjustments (1) 35,840 Balance at December 31, 2015 122,693 Additions (2) 21,659 Payment of related party payable (30,838 ) Fair value adjustments (1) 55,833 Balance at December 31, 2016 169,347 Payment of related party payable (37,311 ) Fair value adjustments (1) (33,111 ) Balance at December 31, 2017 98,925 (1) Fair value adjustments are reported as “(Gain) loss - changes in fair value of related party contingent consideration” and “Other income (expense) - changes in fair value of related party payable” in the Consolidated Statements of Income (Loss). (2) Relates to the acquisition of FSC. See items (c) and (f) above.
Schedule Of Fair Value Assumptions Of Warrant	The fair value of the warrants is estimated on a quarterly basis using a Black-Scholes option pricing model with the following assumptions as of December 31: Assumptions for the Warrant Valuation: 2017 2016 Stock price $ 8.20 $ 10.39 Weighted average exercise price per share 8.63 8.63 Expected term (years) 0.25 1.25 Expected volatility 37.90 % 54.20 % Risk-free interest rate 1.39 % 0.94 % Expected dividend yield — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule Of Components Of Income Before Income Tax	The components of income (loss) before income taxes for the years ended December 31, are as follows: Income (Loss) Before Income Taxes: 2017 2016 2015 Ireland $ (3,123 ) $ (22,866 ) $ (29,469 ) United States 92,754 32,786 100,552 France 3,029 (19,638 ) 6,622 Total income (loss) before income taxes $ 92,660 $ (9,718 ) $ 77,705
Schedule Of Income Tax Payments	The income tax provision consists of the following for the years ended December 31: Income Tax Provision: 2017 2016 2015 Current: United States - Federal $ 18,064 $ 30,738 $ 33,289 United States - State 331 1,081 970 France 265 5,267 1,657 Total current 18,660 37,086 35,916 Deferred: United States - Federal 4,686 (6,443 ) 504 United States - State 1,043 (23 ) 1,234 France — 938 (1,747 ) Total deferred 5,729 (5,528 ) (9 ) Income tax provision $ 24,389 $ 31,558 $ 35,907
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation between Domestic income taxes at the statutory rate and the Company’s provision (benefit) for income taxes is as follows for the years ended December 31: Reconciliation to Effective Income Tax Rate: 2017 2016 2015 Statutory tax rate (1) 12.5 % 12.5 % 33.3 % Differences in international tax rates 22.2 % (31.9 )% 11.0 % Nondeductible changes in fair value of contingent consideration (11.6 )% (165.0 )% 11.9 % Income tax deferred charge — % (9.7 )% 1.3 % Change in valuation allowances (0.7 )% 11.8 % (9.6 )% Nondeductible stock based compensation (0.4 )% (14.8 )% 1.3 % Cross border merger 0.3 % (100.6 )% — % Unrealized tax benefits 1.4 % (15.2 )% 0.4 % State and local taxes (net of federal) 0.3 % (9.6 )% 1.5 % Change in U.S. tax law 3.8 % — % — % Other (1.5 )% (2.3 )% (4.9 )% Effective income tax rate 26.3 % (324.8 )% 46.2 % Income tax provision (benefit) - at statutory tax rate (1) $ 11,582 $ (1,215 ) $ 25,876 Differences in international tax rates 20,557 3,097 8,547 Nondeductible changes in fair value of contingent consideration (10,779 ) 16,036 9,249 Income tax deferred charge — 938 980 Change in valuation allowances (610 ) (1,143 ) (7,425 ) Nondeductible stock based compensation (375 ) 1,436 1,004 Cross-border merger 265 9,773 — Unrecognized tax benefits 1,296 1,475 290 State and local taxes (net of federal) 252 934 1,170 Change in U.S. tax law 3,513 — — Other (1,312 ) 227 (3,784 ) Income tax provision - at effective income tax rate $ 24,389 $ 31,558 $ 35,907 (1) The statutory rate reflects the Irish statutory tax rate of 12.5% for fiscal 2017 and 2016, and the French statutory tax rate of 33.3% for fiscal 2015.
Summary of Unrecognized Tax Benefits	The following table summarizes the activity related to the Company’s unrecognized tax benefits for the twelve months ended December 31: Unrecognized Tax Benefit Activity 2017 2016 2015 Balance at January 1: $ 1,686 $ 448 $ — Additions based on tax positions related to the current year 2,268 1,578 448 Reductions for tax positions of prior years — (340 ) — Balance at December 31: $ 3,954 $ 1,686 $ 448
Schedule of Deferred Tax Assets and Liabilities	The net deferred tax assets/liabilities at December 31, 2017 and 2016 resulted from the following temporary differences: Net Deferred Tax Assets and Liabilities: 2017 2016 Deferred tax assets: Net operating loss carryforwards $ 9,831 $ 11,566 Amortization 7,563 — Stock based compensation 4,375 5,012 Fair value royalty agreements 635 3,386 Fair value contingent consideration 870 2,152 Other 406 583 Gross deferred tax assets 23,680 22,699 Deferred tax liabilities: Amortization (2,419 ) (4,349 ) Accounts receivable (936 ) (3,319 ) Prepaid expenses (1,094 ) — Gross deferred tax liabilities (4,449 ) (7,668 ) Less: valuation allowances (15,354 ) (7,599 ) Net deferred tax assets $ 3,877 $ 7,432

Post-Retirement Benefit Plans (

Post-Retirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Schedule Of Defined Benefit Plan Assumptions	The benefit obligation is calculated as the present value of estimated future benefits to be paid, using the following assumptions for the years ended December 31: Retirement Benefit Obligation Assumptions: 2017 2016 2015 Compensation rate increase 3.00 % 3.00 % 3.00 % Discount rate 1.25 % 1.31 % 2.03 % Employee turn-over Actuarial standard and average of the last 5 years Average age of retirement 60 to 65 years actuarial standard based on age and professional status
Schedule of Changes in Accumulated Postemployment Benefit Obligations	Changes in the funded status of the retirement indemnity benefit plans were as follows for the years ended December 31: Retirement Benefit Obligation Activity: 2017 2016 Retirement indemnity benefit obligation, beginning of year $ 2,431 $ 2,170 Service cost 132 123 Interest cost 21 29 Plan amendment (829 ) — Curtailment gain (717 ) — Actuarial (loss) gain (25 ) 203 Exchange rate changes 290 (94 ) Retirement indemnity benefit obligation, end of year $ 1,303 $ 2,431
Schedule Of Defined Benefit Plan Expected Future Benefit	The future expected benefits to be paid over the next five years and for the five years thereafter is as follows for the years ended December 31: Future Retirement Indemnity Benefit Obligation: Balance 2018 $ — 2019 12 2020 — 2021 — 2022 — Next five years 198 Total 210

Other Assets and Liabilities (T

Other Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Various other assets and liabilities are summarized for the years ended December 31, as follows: Prepaid Expenses and Other Current Assets: 2017 2016 Valued-added tax recoverable $ 1,206 $ 736 Prepaid expenses 7,106 3,442 Advance to suppliers and other current assets 128 1,265 Income tax receivable 518 451 Total $ 8,958 $ 5,894
Schedule of Other Non-Current Assets	Other Non-Current Assets: 2017 2016 Deferred tax assets $ 3,877 $ 7,432 Long-term deposit 3,350 — Other 3,022 99 Total $ 10,249 $ 7,531
Schedule of Accrued Expenses	Accrued Expenses: 2017 2016 Accrued compensation $ 3,157 $ 3,291 Accrued social charges 1,204 794 Accrued employee severance (see Note 15: Restructuring Costs ) 1,000 — Customer allowances 10,613 7,981 Accrued ELAA payment 20,000 — Accrued CMO charges 2,327 936 Accrued contract sales organization and marketing costs 7,641 — Other 4,984 4,220 Total $ 50,926 $ 17,222
Schedule of Other Non-Current Liabilities	Other Non-Current Liabilities: 2017 2016 Provision for retirement indemnity $ 1,303 $ 2,431 Customer allowances 1,636 905 Unrecognized tax benefits 3,954 1,565 Other 191 374 Total $ 7,084 $ 5,275

Contingent Liabilities and Co43

Contingent Liabilities and Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity Schedule	The following table presents contractual obligations of the Company at December 31, 2017 : Payments Due by Period Contractual Obligations: Total Less than 1 to 3 3 to 5 More than Long-term debt $ 267 $ 111 $ 156 $ — $ — Long-term related party payable (1) 163,100 22,173 26,080 37,822 77,025 Purchase commitments (2) 47,680 10,512 13,937 9,062 14,169 Operating leases 4,957 1,721 1,912 1,136 188 Total contractual cash obligations $ 216,004 $ 34,517 $ 42,085 $ 48,020 $ 91,382 (1) On February 12, 2018, Avadel Pharmaceuticals plc (the “Company”), together with its subsidiaries Avadel Pharmaceuticals (USA), Inc., Avadel Pediatrics, Inc., FSC Therapeutics, LLC (“FSC Therapeutics”), and Avadel US Holdings, Inc. (“Holdings”), as the “Sellers,” entered into an asset purchase agreement (the “Purchase Agreement”) with Cerecor, Inc. (“Cerecor”). At the closing under the Purchase Agreement, on February 16, 2018, Cerecor purchased from the Sellers four pediatric commercial stage assets – Karbinal™ ER, Cefaclor, Flexichamber™ and AcipHex® Sprinkle™, together with certain associated business assets – which were held by FSC Therapeutics and FSC Laboratories, Inc., which is also a subsidiary of the Company (collectively “FSC”). The Company acquired FSC in February 2016 from Deerfield CSF, LLC (“Deerfield CSF”) and certain of its affiliates. Pursuant to the Purchase Agreement, Cerecor assumed the Company’s remaining payment obligations to Deerfield CSF under the Membership Interest Purchase Agreement dated February 5, 2016, between Holdings, Flamel Technologies SA (the predecessor of the Company) and Deerfield CSF and certain of its affiliates, which payment obligations consist of the following (collectively, the “Assumed Obligations”): (i) a quarterly payment of $263 beginning in July 2018 and ending in October 2020, amounting to an aggregate payment obligation of $2,625; (ii) a payment in January 2021 of $15,263; and (iii) a quarterly royalty payment of 15% on net sales of the FSC products through February 5, 2026 (“FSC Product Royalties”), in an aggregate amount of up to approximately $10,300. All three of these amounts, which total approximately $29,000, are included within the Long-term related party payable line above. See Note 21: Subsequent Events for a further discussion. (2) This line includes the twenty-year commitment, which amounts to $19,705 and has been assumed by Cerecor as part of the Purchase Agreement. See Note 21: Subsequent Events for a further discussion . Commitments for these arrangements, at maximum quantities and at contractual prices over the remaining life of the contract, and excluding any waived commitments, are as follows for the years ended December 31: Purchase Commitments: Balance 2018 $ 10,512 2019 9,406 2020 4,531 2021 4,531 2022 4,531 Thereafter 14,169 Total $ 47,680
Schedule of Future Minimum Rental Payments for Operating Leases	The Company and our subsidiaries lease office facilities under noncancelable operating leases expiring at various dates. Rent expense, net of rental income, was $1,146 , $970 and $752 in 2017, 2016, and 2015, respectively. Minimum rental commitments for non-cancelable leases in effect at December 31, 2017 are as follows: Lease Commitment: Balance 2018 $ 1,417 2019 919 2020 812 2021 548 2022 559 Thereafter 188 Total $ 4,443

Restructuring Costs (Tables)

Restructuring Costs (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	The following table sets forth activities for the Company’s cost reduction plan obligations for the year ended December 31, 2017 : Severance Obligation: 2017 Balance of restructuring accrual at January 1, $ — Charges for employee severance, benefits and other 3,259 Payments (2,600 ) Foreign currency impact 341 Balance of restructuring accrual at December 31, $ 1,000

Equity Instruments and Stock 45

Equity Instruments and Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	Compensation expense included in the Company’s consolidated statements of income (loss) for all stock-based compensation arrangements was as follows for the periods ended December 31: Stock-based Compensation Expense: 2017 2016 2015 Research and development $ 672 $ 3,523 $ 1,587 Selling, general and administrative 7,400 11,156 6,154 Total stock-based compensation expense $ 8,072 $ 14,679 $ 7,741
Schedule of Share Based Payment Award Stock Options and Warrant Grants Valuation Assumptions	The weighted-average assumptions under the Black-Scholes option-pricing model for stock option and warrant grants as of December 31, 2017 , 2016 and 2015 , are as follows: Stock Option and Warrant Assumptions: 2017 2016 2015 Stock option grants: Expected term (years) 6.25 6.25 6.25 Expected volatility 58.82 % 58.39 % 58.59 % Risk-free interest rate 2.20 % 2.04 % 1.89 % Expected dividend yield — — — Warrant grants: Expected term (years) — 2.50 2.50 Expected volatility — % 60.57 % 55.00 % Risk-free interest rate — % 0.82 % 0.89 % Expected dividend yield — — —
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the combined stock option activity and other data for the Company’s stock option plans for the year ended December 31, 2017 is as follows: Stock Option Activity and Other Data: Number of Stock Options Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Stock options outstanding, January 1, 2017 3,732 $ 12.07 Granted 1,477 9.24 Exercised (14 ) 4.99 Forfeited (46 ) 12.88 Expired (108 ) 13.47 Stock options outstanding, December 31, 2017 5,041 $ 11.34 8.19 years $ 1,187 Stock options exercisable, December 31, 2017 1,917 $ 11.79 6.68 years $ 1,161
Schedule of Stockholders' Equity Note, Warrants or Rights	A summary of the combined warrant activity and other data for the year ended December 31, 2017 is as follows: Warrant Activity and Other Data: Number of Warrants Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Warrants outstanding, January 1, 2017 959 $ 16.05 Granted — — Exercised (55 ) 6.14 Forfeited — — Expired (10 ) 6.14 Warrants outstanding, December 31, 2017 894 $ 16.77 1.51 years $ — Warrants exercisable, December 31, 2017 894 $ 16.77 1.51 years $ —
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	A summary of the Company’s restricted share awards as of December 31, 2017 , and changes during the year then ended, is reflected in the table below. Restricted Share Activity and Other Data: Number of Restricted Share Awards Weighted Average Grant Date Fair Value Non-vested restricted share awards outstanding, January 1, 2017 573 $ 12.57 Granted 271 8.95 Vested (23 ) 7.31 Forfeited (2 ) 16.27 Non-vested restricted share awards outstanding, December 31, 2017 819 $ 11.51

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share Reconciliation	A reconciliation of basic and diluted net income (loss) per share, together with the related shares outstanding in thousands for the years ended December 31, is as follows: Net Income (Loss) Per Share: 2017 2016 2015 Net income (loss) $ 68,271 $ (41,276 ) $ 41,798 Weighted average shares: Basic shares 40,465 41,248 40,580 Effect of dilutive securities—options and warrants outstanding 1,300 — 3,039 Diluted shares 41,765 41,248 43,619 Net income (loss) per share - basic $ 1.69 $ (1.00 ) $ 1.03 Net income (loss) per share - diluted $ 1.63 $ (1.00 ) $ 0.96

Comprehensive Income (Loss) (Ta

Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table shows the components of accumulated other comprehensive income (loss) for the twelve months ended December 31, net of immaterial tax effects: Accumulated Other Comprehensive Income (Loss): 2017 2016 2015 Foreign currency translation adjustment: Beginning balance $ (23,336 ) $ (22,312 ) $ (7,225 ) Net other comprehensive income (loss) 134 (1,024 ) (15,087 ) Balance at December 31, (23,202 ) (23,336 ) (22,312 ) Unrealized gain (loss) on marketable securities, net Beginning balance (229 ) (345 ) (198 ) Net other comprehensive income (loss), net of $28, $16, ($20), tax, respectively 165 116 (147 ) Balance at December 31, (64 ) (229 ) (345 ) Accumulated other comprehensive loss at December 31, $ (23,266 ) $ (23,565 ) $ (22,657 )

Company Operations by Product48

Company Operations by Product, Customer and Geographic Area (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Revenue from External Customers by Product and Services	The following table presents a summary of total revenues by these products for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Product: 2017 2016 2015 Bloxiverz $ 45,596 $ 82,896 $ 150,083 Vazculep 38,187 39,796 20,151 Akovaz 80,617 16,831 — Other 8,441 7,699 2,054 Total product sales and services 172,841 147,222 172,288 License and research revenue 404 3,024 721 Total revenue $ 173,245 $ 150,246 $ 173,009
Schedule of Revenue by Major Customers by Reporting Segments	The following table presents a summary of total revenues by significant customer for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Significant Customer: 2017 2016 2015 Customer A $ 53,342 $ 17,728 $ — Customer B 44,762 51,648 53,988 Customer C 37,965 39,359 60,420 Customer D 25,691 30,916 43,434 Others 11,081 7,571 14,446 Total product sales and services 172,841 147,222 172,288 License and research revenue 404 3,024 721 Total revenue $ 173,245 $ 150,246 $ 173,009
Revenue from External Customers by Geographic Areas	The following table summarizes revenues by geographic region for the twelve months ended December 31, 2017 , 2016 , and 2015 : Revenue by Geographic Region: 2017 2016 2015 United States $ 172,841 $ 147,283 $ 172,179 France — — 89 Ireland 404 2,963 741 Total revenues $ 173,245 $ 150,246 $ 173,009
Long-lived Assets by Geographic Areas	ep and Akovaz, and to deliver certain raw materials used in their production, from which we derive a ma

Summary of Significant Accoun49

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares	Mar. 06, 2017USD ($)	Dec. 31, 2016€ / sharesshares	Dec. 31, 2016$ / sharesshares
Class of Stock [Line Items]
Authorized share capital	$ 5,500,000
Ordinary shares, shares authorized (in shares) | shares	500,000,000		500,000,000	500,000,000
Ordinary shares, nominal value (in usd or euro per share) | (per share)	$ 0.01		€ 0.122	$ 0.01
Preferred shares, shares authorized (in shares) | shares	50,000,000		50,000,000	50,000,000
Preferred shares, nominal value (in usd per share) | $ / shares	$ 0.01			$ 0.01
Adjustment to reduce share premium		$ 317,254,000
Adjustment to increase available distributable reserves		$ 317,254,000
Ordinary shares
Class of Stock [Line Items]
Cross-border merger nominal value adjustment	$ (5,937,000)
Additional paid-in capital
Class of Stock [Line Items]
Cross-border merger nominal value adjustment	$ 0

Summary of Significant Accoun50

Summary of Significant Accounting Policies - Revenue (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in Accounting Estimate [Line Items]
Product sales and services	$ 172,841	$ 147,222	$ 172,288
License and research revenue	404	$ 3,024	$ 721
Change in Accounting Method Accounted for as Change in Estimate
Change in Accounting Estimate [Line Items]
Product sales and services	$ 5,981
Effect on earnings per diluted share (in usd per share)	$ 0.05

Summary of Significant Accoun51

Summary of Significant Accounting Policies - Property and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2017
Laboratory equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	8 years
Laboratory equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	4 years
Software, office and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	3 years
Furniture, fixtures and fittings | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	10 years
Furniture, fixtures and fittings | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives (in years)	5 years

Effect of New Accounting Stan52

Effect of New Accounting Standards (Details Textual) $ in Thousands	Dec. 31, 2016USD ($)
Accounting Changes and Error Corrections [Abstract]
Income tax deferred charge	$ (11,156)

Fair Value Measurements - Measu

Fair Value Measurements - Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 77,511	$ 114,980
Long-term related party payable, less current portion	73,918	135,170
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	468	4,033
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	44,481
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	9,262	57,348
Government securities - U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	19,050	42,814
Government securities - Non-U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		233
Other fixed-income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,250	10,471
Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		81
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	44,481
Fair Value Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	44,949	4,033
Fair Value Measurements, Recurring | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	468	4,033
Fair Value Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	32,562	110,947
Fair Value Measurements, Recurring | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	9,262	57,348
Fair Value Measurements, Recurring | Level 2 | Government securities - U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	19,050	42,814
Fair Value Measurements, Recurring | Level 2 | Government securities - Non-U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0	233
Fair Value Measurements, Recurring | Level 2 | Other fixed-income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,250	10,471
Fair Value Measurements, Recurring | Level 2 | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		81
Fair Value Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term related party payable, less current portion	98,925	169,347
Total liabilities	$ 98,925	$ 169,347

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	$ 77,592	$ 115,218
Unrealized Gains	32	1,234
Unrealized Losses	(113)	(1,472)
Fair Value	77,511	114,980
Gross realized gain	1,677	1,265	$ 241
Gross realized loss	1,390	586	$ 677
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	443	3,689
Unrealized Gains	31	409
Unrealized Losses	(6)	(65)
Fair Value	468	4,033
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	44,525
Unrealized Gains	0
Unrealized Losses	(44)
Fair Value	44,481
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	9,285	57,871
Unrealized Gains	1	89
Unrealized Losses	(24)	(612)
Fair Value	9,262	57,348
Government securities - U.S.
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	19,080	43,049
Unrealized Gains	0	515
Unrealized Losses	(30)	(750)
Fair Value	19,050	42,814
Government securities - Non-U.S.
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost		247
Unrealized Gains		0
Unrealized Losses		(14)
Fair Value		233
Other fixed-income securities
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	4,259	10,281
Unrealized Gains	0	221
Unrealized Losses	(9)	(31)
Fair Value	$ 4,250	10,471
Other securities
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost		81
Unrealized Gains		0
Unrealized Losses		0
Fair Value		$ 81

Marketable Securities - Schedul

Marketable Securities - Schedule of Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 77,511	$ 114,980
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Less than 1 Year	1,033
1-5 Years	6,826
5-10 Years	1,403
Greater than 10 Years	0
Fair Value	9,262	57,348
Government securities - U.S.
Schedule of Available-for-sale Securities [Line Items]
Less than 1 Year	50
1-5 Years	17,509
5-10 Years	977
Greater than 10 Years	514
Fair Value	19,050	42,814
Other fixed-income securities
Schedule of Available-for-sale Securities [Line Items]
Less than 1 Year	0
1-5 Years	4,250
5-10 Years	0
Greater than 10 Years	0
Fair Value	4,250	$ 10,471
Total
Schedule of Available-for-sale Securities [Line Items]
Less than 1 Year	1,083
1-5 Years	28,585
5-10 Years	2,380
Greater than 10 Years	514
Fair Value	$ 32,562

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventory reserves	$ 1,039	$ 3,223
Finished goods	4,774	2,429
Raw materials	1,383	829
Total	$ 6,157	$ 3,258

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Less - accumulated depreciation	$ (15,028)	$ (12,457)
Property and equipment, net	3,001	3,320
Depreciation	1,224	601	$ 568
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	10,135	9,019
Software, office and computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	3,115	2,519
Furniture, fixtures and fittings
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 4,779	$ 4,239

Acquisitions (Details Textual)

Acquisitions (Details Textual) - USD ($)	Feb. 05, 2016	Feb. 29, 2016	Dec. 31, 2013	Feb. 28, 2013	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combination, Separately Recognized Transactions [Line Items]
Payments to acquire businesses, gross					$ 37,311,000	$ 30,838,000	$ 27,897,000
Percentage of royalty payable on net sales			0.834%
Deerfield CSF LLC | Affiliated Entity
Business Combination, Separately Recognized Transactions [Line Items]
Percentage of royalty payable on net sales				1.75%
FSC
Business Combination, Separately Recognized Transactions [Line Items]
Business combination, consideration transferred	$ 21,659,000
Payment for settlement of net working capital	$ 467,000
Business combination, pro forma information, revenue of acquiree since acquisition date, actual						5,985,000
Business combination, pro forma information, loss of acquiree since acquisition date, actual						$ 5,839,000
FSC | Maximum
Business Combination, Separately Recognized Transactions [Line Items]
Acquired intangible assets useful life (in years)	15 years
FSC | Minimum
Business Combination, Separately Recognized Transactions [Line Items]
Acquired intangible assets useful life (in years)	9 years
FSC | Deerfield CSF LLC | Affiliated Entity
Business Combination, Separately Recognized Transactions [Line Items]
Business combination, recognized identifiable assets acquired and liabilities assumed, noncurrent liabilities, long-term debt	$ 15,000,000
Payments to acquire businesses, gross	$ 1,050,000	$ 1,050,000
Debt instrument, term (in years)	5 years	5 years
Business combination, contingent consideration, liability	$ 6,659,000
Percentage of royalty payable on net sales	15.00%	15.00%
FSC | Deerfield CSF LLC | Affiliated Entity | Maximum
Business Combination, Separately Recognized Transactions [Line Items]
Royalty guarantees, commitments, amount	$ 12,500,000
Royalty guarantees, commitments, term (in years)	10 years	10 years

Acquisitions - Purchase Price A

Acquisitions - Purchase Price Allocation (Details) - FSC $ in Thousands	Feb. 05, 2016USD ($)
Business Acquisition [Line Items]
Accounts receivable	$ 142
Inventories	1,135
Prepaid expenses and other current assets	1,712
Deferred tax assets	853
Other assets	277
Accounts payable and other liabilities	(3,827)
Total	21,192
Marketing Rights
Business Acquisition [Line Items]
Intangible assets	16,600
Developed Technology
Business Acquisition [Line Items]
Intangible assets	$ 4,300

Acquisitions - Pro Forma Inform

Acquisitions - Pro Forma Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Net revenues	$ 150,721	$ 178,104
Net income (loss)	$ (42,290)	$ 30,965

Goodwill and Intangible Asset61

Goodwill and Intangible Assets - Net Book Value (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortizable intangible assets:
Amortizable intangible assets: Gross Value	$ 106,072	$ 32,961
Amortizable intangible assets: Accumulated Amortization	(13,783)	(10,124)
Amortizable intangible assets: Net Book Value	92,289	22,837
Unamortizable intangible assets:
Unamortizable intangible assets: Goodwill, Gross Value	18,491	18,491
Unamortizable intangible assets: Accumulated Amortization	0	0
Unamortizable intangible assets: Net Book Value	18,491	18,491
In Process Research and Development | Noctiva
Amortizable intangible assets:
Amortizable intangible assets: Gross Value	73,111	0
Amortizable intangible assets: Accumulated Amortization	(1,401)	0
Amortizable intangible assets: Net Book Value	71,710	0
In Process Research and Development | Vazculep
Amortizable intangible assets:
Amortizable intangible assets: Gross Value	12,061	12,061
Amortizable intangible assets: Accumulated Amortization	(9,616)	(8,801)
Amortizable intangible assets: Net Book Value	2,445	3,260
Marketing Rights
Amortizable intangible assets:
Amortizable intangible assets: Gross Value	16,600	16,600
Amortizable intangible assets: Accumulated Amortization	(2,132)	(1,019)
Amortizable intangible assets: Net Book Value	14,468	15,581
Developed Technology
Amortizable intangible assets:
Amortizable intangible assets: Gross Value	4,300	4,300
Amortizable intangible assets: Accumulated Amortization	(634)	(304)
Amortizable intangible assets: Net Book Value	$ 3,666	$ 3,996

Goodwill and Intangible Asset62

Goodwill and Intangible Assets - Estimate Future Amortization (Details) $ in Thousands	Dec. 31, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 7,882
2,019	7,882
2,020	7,882
2,021	7,067
2,022	$ 7,067

Goodwill and Intangible Asset63

Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Intangible asset amortization		$ 3,659	$ 13,888	$ 12,564
Upfront payment for developed technology		53,111	0	$ 0
Accrued ELAA payment		20,000	$ 0
Transaction costs		$ 3,111
Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)		15 years
Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)		3 years
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Developed technology acquired		$ 73,111
Upfront payment for developed technology		50,000
Accrued ELAA payment		$ 20,000
Amortization period (in years)	13 years

Long-Term Debt (Details Textual

Long-Term Debt (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Capitalization, Long-term Debt [Line Items]
Repayments of loans	$ 115,000	$ 277,000	$ 747,000
Research and development arrangement, waiver of loan repayment	539,000	0	$ 1,498,000
French Ministry Of Research
Schedule of Capitalization, Long-term Debt [Line Items]
Proceeds from loans or conditional grants	$ 267,000	$ 815,000

Long-Term Related Party Payab65

Long-Term Related Party Payable - Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-Term Related Party Payable
Related party payable, beginning balance	$ 169,347	$ 122,693	$ 114,750
Payments to Related Parties	(37,311)	(30,838)	(27,897)
Changes in Fair Value of Related Party Payable, Operating Income	(31,040)	49,285	30,957
Changes in Fair Value of Related Party Payable, Other Income	(2,071)
Related party payable, ending balance	98,925	169,347	$ 122,693
Less: Current portion	(25,007)	(34,177)
Total long-term related party payable	73,918	135,170
Financing-related:
Long-Term Related Party Payable
Related party payable, beginning balance	15,000
Payments to Related Parties	0
Changes in Fair Value of Related Party Payable, Operating Income	0
Changes in Fair Value of Related Party Payable, Other Income	0
Related party payable, ending balance	15,000	15,000
Warrant | Acquisition-related contingent consideration:
Long-Term Related Party Payable
Related party payable, beginning balance	11,217
Payments to Related Parties	0
Changes in Fair Value of Related Party Payable, Operating Income	(8,738)
Changes in Fair Value of Related Party Payable, Other Income	0
Related party payable, ending balance	2,479	11,217
Earn-out payments | Acquisition-related contingent consideration:
Long-Term Related Party Payable
Related party payable, beginning balance	121,377
Payments to Related Parties	(31,636)
Changes in Fair Value of Related Party Payable, Operating Income	(21,997)
Changes in Fair Value of Related Party Payable, Other Income	0
Related party payable, ending balance	67,744	121,377
Royalty agreement - FSC | Acquisition-related contingent consideration:
Long-Term Related Party Payable
Related party payable, beginning balance	7,291
Payments to Related Parties	(1,246)
Changes in Fair Value of Related Party Payable, Operating Income	(305)
Changes in Fair Value of Related Party Payable, Other Income	0
Related party payable, ending balance	5,740	7,291
Royalty agreement - Deerfield | Financing-related:
Long-Term Related Party Payable
Related party payable, beginning balance	9,794
Payments to Related Parties	(2,999)
Changes in Fair Value of Related Party Payable, Operating Income	0
Changes in Fair Value of Related Party Payable, Other Income	(1,403)
Related party payable, ending balance	5,392	9,794
Royalty agreement - Broadfin | Financing-related:
Long-Term Related Party Payable
Related party payable, beginning balance	4,668
Payments to Related Parties	(1,430)
Changes in Fair Value of Related Party Payable, Operating Income	0
Changes in Fair Value of Related Party Payable, Other Income	(668)
Related party payable, ending balance	$ 2,570	$ 4,668

Long-Term Related Party Payab66

Long-Term Related Party Payable - Warrant Fair Value Assumptions (Details) - Warrant - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Capitalization, Long-term Debt [Line Items]
Stock price (in dollars per share)	$ 8.20	$ 10.39
Weighted average exercise price per share	$ 8.63	$ 8.63
Expected term (years)	3 months	1 year 3 months
Expected volatility	37.90%	54.20%
Risk-free interest rate	1.39%	0.94%
Expected dividend yield	0.00%	0.00%

Long-Term Related Party Payab67

Long-Term Related Party Payable - Payable Balance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Related party payable	$ 98,925	$ 169,347	$ 122,693	$ 114,750
Additions		21,659
Payment of related party payable	(37,311)	(30,838)	(27,897)
Fair value adjustments	$ (33,111)	$ 55,833	$ 35,840

Long-Term Related Party Payab68

Long-Term Related Party Payable (Details Textual) - USD ($)

Feb. 05, 2016

Mar. 13, 2012

Jan. 31, 2021

Feb. 29, 2016

Dec. 31, 2013

Feb. 28, 2013

Mar. 31, 2012

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Mar. 12, 2018

Feb. 23, 2018

Feb. 22, 2018

Mar. 12, 2012

Line of Credit Facility [Line Items]

Number of securities called by each warrant (in shares)

1

Percentage of royalty payable on net sales

0.834%

Cash consideration received on royalty agreement

$ 2,200,000

Payments to acquire businesses, gross

$ 37,311,000

$ 30,838,000

$ 27,897,000

Maximum

Line of Credit Facility [Line Items]

Discounted cash flow risk adjusted discount rate

22.00%

Minimum

Line of Credit Facility [Line Items]

Discounted cash flow risk adjusted discount rate

15.00%

Affiliated Entity | Deerfield CSF LLC

Line of Credit Facility [Line Items]

Percentage of royalty payable on net sales

1.75%

Cash consideration received on royalty agreement

$ 2,600,000

Eclat Pharmaceuticals

Line of Credit Facility [Line Items]

Warrants issued

2

2

2

Warrant term (in years)

6 years

Number of securities called by warrants (in shares)

3,300

3,300,000

3,300,000

Exercise price of warrants (in usd per share)

$ 11

Number of securities called by each warrant (in shares)

1,100

Percentage of earn-out payments

20.00%

Eclat Pharmaceuticals | Exercise Price 1

Line of Credit Facility [Line Items]

Exercise price of warrants (in usd per share)

$ 7.44

Number of securities called by each warrant (in shares)

2,200

FSC | Affiliated Entity | Deerfield CSF LLC

Line of Credit Facility [Line Items]

Percentage of royalty payable on net sales

15.00%

15.00%

Royalty amount

$ 12,500,000

Payments to acquire businesses, gross

$ 1,050,000

$ 1,050,000

Debt instrument, term (in years)

5 years

5 years

FSC | Affiliated Entity | Deerfield CSF LLC | Scenario, Forecast

Line of Credit Facility [Line Items]

Final payment to acquire business gross

$ 15,000,000

FSC | Affiliated Entity | Deerfield CSF LLC | Maximum

Line of Credit Facility [Line Items]

Royalty guarantees, commitments, term (in years)

10 years

10 years

Subsequent event | Eclat Pharmaceuticals

Line of Credit Facility [Line Items]

Exercise price of warrants (in usd per share)

$ 11

Number of securities called by each warrant (in shares)

2,200

Remaining warrants outstanding expired

1,100

Subsequent event | Eclat Pharmaceuticals | Exercise Price 1

Line of Credit Facility [Line Items]

Number of securities called by each warrant (in shares)

2,200

Income Taxes - Income (Loss) Be

Income Taxes - Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Income (loss) before income taxes	$ 92,660	$ (9,718)	$ 77,705
Ireland
Income Taxes [Line Items]
Income (loss) before income taxes	(3,123)	(22,866)	(29,469)
United States
Income Taxes [Line Items]
Income (loss) before income taxes	92,754	32,786	100,552
France
Income Taxes [Line Items]
Income (loss) before income taxes	$ 3,029	$ (19,638)	$ 6,622

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
United States - Federal	$ 18,064	$ 30,738	$ 33,289
United States - State	331	1,081	970
France	265	5,267	1,657
Total current	18,660	37,086	35,916
Deferred:
United States - Federal	4,686	(6,443)	504
United States - State	1,043	(23)	1,234
France	0	938	(1,747)
Total deferred	5,729	(5,528)	(9)
Income tax provision	$ 24,389	$ 31,558	$ 35,907

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory tax rate	12.49946%	12.50%	33.30%
Differences in international tax rates	22.20%	(31.90%)	11.00%
Nondeductible changes in fair value of contingent consideration	(11.60%)	(165.00%)	11.90%
Income tax deferred charge	0.00%	(9.70%)	1.30%
Change in valuation allowances	(0.70%)	11.80%	(9.60%)
Nondeductible stock based compensation	(0.40%)	(14.80%)	1.30%
Cross border merger	0.30%	(100.60%)	0.00%
Unrealized tax benefits	1.40%	(15.20%)	0.40%
State and local taxes (net of federal)	0.30%	(9.60%)	1.50%
Change in U.S. tax law	3.80%	0.00%	0.00%
Other	(1.50%)	(2.30%)	(4.90%)
Effective income tax rate	26.30%	(324.80%)	46.20%
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax provision (benefit) - at statutory tax rate	$ 11,582	$ (1,215)	$ 25,876
Nondeductible changes in fair value of contingent consideration	(10,779)	16,036	9,249
Change in valuation allowances	(610)	(1,143)	(7,425)
Income tax deferred charge	0	938	980
International tax rates differential	20,557	3,097	8,547
Nondeductible stock based compensation	(375)	1,436	1,004
Cross-border merger	265	9,773	0
Unrecognized tax benefits	1,296	1,475	290
State and local taxes (net of federal)	252	934	1,170
Change in U.S. tax law	3,513	0	0
Other	(1,312)	227	(3,784)
Income tax provision	$ 24,389	$ 31,558	$ 35,907

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unrecognized Tax Benefit Activity [Roll Forward]
Beginning balance	$ 1,686	$ 448	$ 0
Additions based on tax positions related to the current year	2,268	1,578	448
Reductions for tax positions of prior years	0	(340)	0
Ending balance	$ 3,954	$ 1,686	$ 448

Income Taxes - Deferred Taxes (

Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 9,831	$ 11,566
Amortization	7,563	0
Stock based compensation	4,375	5,012
Fair value royalty agreements	635	3,386
Fair value contingent consideration	870	2,152
Other	406	583
Gross deferred tax assets	23,680	22,699
Deferred tax liabilities:
Amortization	(2,419)	(4,349)
Accounts receivable	(936)	(3,319)
Prepaid expenses	(1,094)	0
Gross deferred tax liabilities	(4,449)	(7,668)
Less: valuation allowances	(15,354)	(7,599)
Net deferred tax assets	$ 3,877	$ 7,432

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Statutory tax rate		12.49946%	12.50%	33.30%
Increase (decrease) in income tax provision		$ 7,343,000	$ 4,349,000
Unrecognized tax benefits could change by up to		600,000
Interest and penalties could change by up to		500,000
Tax cost associated with Tax Cuts and Jobs Act		3,513,000
Income tax provision effect of cross-border merger		265,000	9,773,000	$ 0
Income tax provision effect of transfer of intellectual property		0	938,000	980,000
Unrecognized tax benefits that would impact effective tax rate		3,349,000	1,565,000	291,000
Income tax penalties and interest expense		304,000	26,000	0
Income tax penalties and interest accrued		331,000	26,000
Unremitted earnings		3,038,000
Deferred tax assets, tax credit carryforwards, research		5,272,000	1,775,000
Current deferred tax liabilities			1,601,000
Research tax credit utilized		4,266,000	4,001,000
Income tax charge		24,389,000	31,558,000	35,907,000
Tax-related prepaid expenses			814,000	986,000
Deferred tax assets		7,954,000	10,342,000	13,102,000
Deferred tax amortized rate	7.00%
Income tax deferred charge			11,156,000
Income tax provision related to cross-border merger		4,266,000
Tax charge due to remeasurement		$ 3,513,000	$ 0	$ 0
Ireland
Income Taxes [Line Items]
Statutory tax rate		12.50%	12.50%
Net operating loss carryforwards		$ 39,574,000
Net operating loss carryforwards valuation allowance		4,963,000
Gross research tax credit		518,000
Tax relief amount		8,500,000
France
Income Taxes [Line Items]
Statutory tax rate				33.30%
Net operating loss carryforwards		698,000
Net operating loss carryforwards valuation allowance		233,000
Gross research tax credit		4,754,000	$ 3,376,000
Income tax charge	$ 14,088,000
Removal of operating loss carryforwards		111,495,000
United States
Income Taxes [Line Items]
Net operating loss carryforwards		11,190,000
Net operating loss carryforwards valuation allowance		$ 309,000

Post-Retirement Benefit Plans -

Post-Retirement Benefit Plans - Benefit Obligation Assumptions (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Compensation rate increase	3.00%	3.00%	3.00%
Discount rate	1.25%	1.31%	2.03%
Employee turn-over description	Actuarial standard and average of the last 5 years	Actuarial standard and average of the last 5 years	Actuarial standard and average of the last 5 years
Employee turn-over, average years	5 years	5 years	5 years
Average age of retirement description	60 to 65 years actuarial standard based on age and professional status	60 to 65 years actuarial standard based on age and professional status	60 to 65 years actuarial standard based on age and professional status
Minimum
Defined Benefit Plan Disclosure [Line Items]
Average age of retirement (in years)	60 years	60 years	60 years
Maximum
Defined Benefit Plan Disclosure [Line Items]
Average age of retirement (in years)	65 years	65 years	65 years

Post-Retirement Benefit Plans76

Post-Retirement Benefit Plans - Benefit Obligation Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement indemnity benefit obligation, beginning of year	$ 2,431	$ 2,170
Service cost	132	123
Interest cost	21	29
Plan amendment	(829)	0
Curtailment gain	(717)	0
Actuarial (loss) gain	(25)	203
Exchange rate changes	290	(94)
Retirement indemnity benefit obligation, end of year	$ 1,303	$ 2,431

Post-Retirement Benefit Plans77

Post-Retirement Benefit Plans - Future Obligation (Details) $ in Thousands	Dec. 31, 2017USD ($)
Compensation and Retirement Disclosure [Abstract]
2,018	$ 0
2,019	12
2,020	0
2,021	0
2,022	0
Next five years	198
Total	$ 210

Post-Retirement Benefit Plans78

Post-Retirement Benefit Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Defined contribution plan, cost recognized	$ 123	$ 348	$ 573
Curtailment gain	$ 717	$ 0

Other Assets and Liabilities -

Other Assets and Liabilities - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Valued-added tax recoverable	$ 1,206	$ 736
Prepaid expenses	7,106	3,442
Advance to suppliers and other current assets	128	1,265
Income tax receivable	518	451
Total	$ 8,958	$ 5,894

Other Assets and Liabilities 80

Other Assets and Liabilities - Other Non-Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Deferred tax assets	$ 3,877	$ 7,432
Long-term deposit	3,350	0
Other	3,022	99
Total	$ 10,249	$ 7,531

Other Assets and Liabilities 81

Other Assets and Liabilities - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Accrued compensation	$ 3,157	$ 3,291
Accrued social charges	1,204	794
Accrued employee severance	1,000	0
Customer allowances	10,613	7,981
Accrued ELAA payment	20,000	0
Accrued CMO charges	2,327	936
Accrued contract sales organization and marketing costs	7,641	0
Other	4,984	4,220
Total	$ 50,926	$ 17,222

Other Assets and Liabilities 82

Other Assets and Liabilities - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Provision for retirement indemnity	$ 1,303	$ 2,431	$ 2,170
Customer allowances	1,636	905
Unrecognized tax benefits	3,954	1,686	448	$ 0
Unrecognized tax benefits that would impact effective tax rate	3,349	1,565	$ 291
Other	191	374
Total	$ 7,084	$ 5,275

Contingent Liabilities and Co83

Contingent Liabilities and Commitments (Details Textual) - USD ($)	Aug. 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments And Contingencies [Line Items]
Commitments to purchase services		$ 22,500,000
Minimum amount of services for remaining two years		4,875,000
Purchase commitment		216,004,000
Operating leases, rent expense, net		$ 1,146,000	$ 970,000	$ 752,000
Recipharm AB
Commitments And Contingencies [Line Items]
Purchase commitment, period (in years)					5 years
Contract Manufacturer A
Commitments And Contingencies [Line Items]
Purchase commitment, period (in years)		20 years
Purchase commitment		$ 19,705,000
Contract Manufacturer B
Commitments And Contingencies [Line Items]
Purchase commitment, period (in years)	6 years
Inventories
Commitments And Contingencies [Line Items]
Payment of purchase commitment		$ 6,898,000

Contingent Liabilities and Co84

Contingent Liabilities and Commitments - Purchase Commitments (Details) - Inventories $ in Thousands	Dec. 31, 2017USD ($)
Purchase Commitments:
2,018	$ 10,512
2,019	9,406
2,020	4,531
2,021	4,531
2,022	4,531
Thereafter	14,169
Total	$ 47,680

Contingent Liabilities and Co85

Contingent Liabilities and Commitments - Lease Commitments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Lease Commitment:
2,018	$ 1,417
2,019	919
2,020	812
2,021	548
2,022	559
Thereafter	188
Total	$ 4,443

Contingent Liabilities and Co86

Contingent Liabilities and Commitments - Contractual Obligations (Details) - USD ($) $ in Thousands	Feb. 12, 2018	Jan. 31, 2021	Dec. 31, 2013	Dec. 31, 2017
Long-term debt
Total				$ 267
Less than 1 Year				111
1 to 3 Years				156
3 to 5 Years				0
More than 5 Years				0
Long-term related party payable (undiscounted)
Total				163,100
Less than 1 Year				22,173
1 to 3 Years				26,080
3 to 5 Years				37,822
More than 5 Years				77,025
Purchase commitments(2)
Total				47,680
Less than 1 Year				10,512
1 to 3 Years				13,937
3 to 5 Years				9,062
More than 5 Years				14,169
Operating leases
Total				4,957
Less than 1 Year				1,721
1 to 3 Years				1,912
3 to 5 Years				1,136
More than 5 Years				188
Total contractual cash obligations
Total				216,004
Less than 1 Year				34,517
1 to 3 Years				42,085
3 to 5 Years				48,020
More than 5 Years				91,382
Percentage of royalty payable on net sales			0.834%
Discontinued operations, disposed of by sale | Subsequent event | 2016 MIPA
Total contractual cash obligations
Interest payment	$ 263
Total remaining payment obligation	2,625
Repayments of debt		$ 15,263
Long-term related party payable	$ 29,000
FSC | Discontinued operations, disposed of by sale | Subsequent event | 2016 MIPA
Total contractual cash obligations
Percentage of royalty payable on net sales	15.00%
Royalty payable on net sales, maximum	$ 10,300
Contract Manufacturer A
Total contractual cash obligations
Total				$ 19,705

Restructuring Costs - (Details

Restructuring Costs - (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 3,259,000
Curtailment gain	717,000	$ 0
Lyon France Workforce Reduction | Employee Severance
Restructuring Cost and Reserve [Line Items]
Percent reduction in workforce			50.00%
Restructuring costs	$ 2,542,000	$ 0

Restructuring Costs - Severance

Restructuring Costs - Severance Obligation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance of accrued costs	$ 0
Charges for employee severance, benefits and other	3,259
Payments	(2,600)
Foreign currency impact	341
Ending balance of accrued costs	$ 1,000

Equity Instruments and Stock 89

Equity Instruments and Stock Based Compensation (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / shares	Feb. 12, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016€ / shares	Dec. 31, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares, shares authorized (in shares)	500,000,000						500,000,000
Ordinary shares, nominal value (in usd or euro per share) | (per share)	$ 0.01					€ 0.122	$ 0.01
Ordinary shares, shares issued (in shares)	41,463,000						41,371,000
Ordinary shares, shares outstanding (in shares)	39,346,000						41,371,000
Preferred shares, shares authorized (in shares)	50,000,000						50,000,000
Preferred shares, nominal value (in usd per share) | $ / shares	$ 0.01						$ 0.01
Preferred shares, shares outstanding (in shares)	0						0
Authorized repurchase amount | $					$ 25,000,000
Share repurchases (in shares)	2,117,000
Share repurchases | $	$ (22,361,000)						$ 0
Unrecognized compensation expense | $	$ 13,101,000
Weighted average period for unrecognized expense (in years)	3 years 1 month 7 days
Excess tax benefit related to stock-based compensation | $	$ 0	$ 0	$ 1,767,000
Aggregate intrinsic value of options exercised | $	$ 1,161,000	$ 58,000	$ 10,063,000
Grant date fair value of options granted (in usd per share) | $ / shares	$ 9.24	$ 6.14	$ 9.38
Number of securities called by each warrant (in shares)	1
Aggregate intrinsic value of warrants exercised | $	$ 0		$ 2,698,000				$ 0
Grant date fair value of warrants granted (in usd per share) | $ / shares		$ 2.99	$ 5.92
Additional warrants outstanding	3,300,000
Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period for unrecognized expense (in years)	0 years	2 years 6 months	2 years 6 months
Vesting period (in years)	1 year
Expiration period (in years)	4 years
Granted (in shares)	0
Free Share Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)		4 years
Holding period (in years)	2 years
Granted (in shares)	271,000	0
Weighted average grant fair value of free share awards | $ / shares	$ 8.95		$ 12.11
Free Share Award | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period (in years)		2 years
Free Share Award | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period (in years)		4 years
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Expiration period (in years)	10 years
Number of shares authorized (in shares)	2,290,147,000
Subsequent event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized repurchase amount | $				$ 20,000,000
2017 Avadel Employee Share Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares, nominal value (in usd or euro per share) | $ / shares	$ 0.01
Shares available for issuance under ESPP	1,000,000

Equity Instruments and Stock 90

Equity Instruments and Stock Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 8,072	$ 14,679	$ 7,741
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	672	3,523	1,587
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 7,400	$ 11,156	$ 6,154

Equity Instruments and Stock 91

Equity Instruments and Stock Based Compensation - Fair Value Assumptions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	3 years 1 month 7 days
Excess tax benefit related to stock-based compensation	$ 0	$ 0	$ 1,767,000
Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	0 years	2 years 6 months	2 years 6 months
Expected volatility	0.00%	60.57%	55.00%
Risk-free interest rate	0.00%	0.82%	0.89%
Expected dividend yield	0.00%	0.00%	0.00%
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Expected volatility	58.82%	58.39%	58.59%
Risk-free interest rate	2.20%	2.04%	1.89%
Expected dividend yield	0.00%	0.00%	0.00%

Equity Instruments and Stock 92

Equity Instruments and Stock Based Compensation - Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Stock Options, Outstanding [Roll Forward]
Stock options outstanding, beginning balance (in shares) | shares	3,732
Granted (in shares) | shares	1,477
Exercised (in shares) | shares	(14)
Forfeited (in shares) | shares	(46)
Expired (in shares) | shares	(108)
Stock options outstanding, ending balance (in shares) | shares	5,041
Stock options exercisable (in shares) | shares	1,917
Stock Options, Outstanding, Weighted Average Exercise Price [Abstract]
Stock options outstanding, beginning balance (in usd per share) | $ / shares	$ 12.07
Granted (in usd per share) | $ / shares	9.24
Exercised (in usd per share) | $ / shares	4.99
Forfeited (in usd per share) | $ / shares	12.88
Expired (in usd per share) | $ / shares	13.47
Stock options outstanding, ending balance (in usd per share) | $ / shares	11.34
Stock options exercisable (in usd per share) | $ / shares	$ 11.79
Stock options outstanding, Weighted Average Remaining Contractual Life (in years)	8 years 2 months 9 days
Stock options exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 8 months 5 days
Stock options outstanding, Aggregate Intrinsic Value | $	$ 1,187
Stock options exercisable, Aggregate Intrinsic Value | $	$ 1,161

Equity Instruments and Stock 93

Equity Instruments and Stock Based Compensation - Warrants (Details) - Warrant $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Warrant Activity and Other Data, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	959
Granted (in shares) | shares	0
Exercised (in shares) | shares	(55)
Forfeited (in shares) | shares	0
Expired (in shares) | shares	(10)
Outstanding, ending balance (in shares) | shares	894
Warrants exercisable (in shares) | shares	894
Warrant Activity and Other Data, Weighted Average Exercise Price [Abstract]
Warrants outstanding, beginning balance (in usd per share) | $ / shares	$ 16.05
Granted (in usd per share) | $ / shares	0
Exercised (in usd per share) | $ / shares	6.14
Forfeited (in usd per share) | $ / shares	0
Expired (in usd per share) | $ / shares	6.14
Warrants outstanding, ending balance (in usd per share) | $ / shares	16.77
Warrants exercisable (in usd per share) | $ / shares	$ 16.77
Warrants outstanding, Weighted Average Remaining Contractual Life (in years)	1 year 6 months 5 days
Warrants exercisable, Weighted Average Remaining Contractual Life (in years)	1 year 6 months 5 days
Warrants outstanding, Aggregate Intrinsic Value | $	$ 0
Warrants exercisable, Aggregate Intrinsic Value | $	$ 0

Equity Instruments and Stock 94

Equity Instruments and Stock Based Compensation - Free Share Awards (Details) - Free Share Award - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Free Share Activity and Other Data, Nonvested [Roll Forward]
Outstanding, beginning balance (in shares)	573,000
Granted (in shares)	271,000	0
Vested (in shares)	(23,000)
Forfeited (in shares)	(2,000)
Outstanding, ending balance (in shares)	819,000	573,000
Free Share Activity and Other Data, Weighted Average Grant Date Fair Value [Abstract]
Nonvested free share award, beginning balance (in usd per share)	$ 12.57
Granted (in usd per share)	8.95		$ 12.11
Vested (in usd per share)	7.31
Forfeited (in usd per share)	16.27
Nonvested free share award, ending balance (in usd per share)	$ 11.51	$ 12.57

Earnings (Loss) Per Share - Rec

Earnings (Loss) Per Share - Reconciliation of basic and diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income (loss)	$ 68,271	$ (41,276)	$ 41,798
Weighted average shares:
Basic shares (in shares)	40,465	41,248	40,580
Effect of dilutive securities - options and warrants outstanding (in shares)	1,300	0	3,039
Diluted shares (in shares)	41,765	41,248	43,619
Net income (loss) per share - basic (in usd per share)	$ 1.69	$ (1)	$ 1.03
Net income (loss) per share - diluted (in usd per share)	$ 1.63	$ (1)	$ 0.96

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details Textual) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	6,368	8,564	635

Comprehensive Income (Loss) (De

Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss)
Beginning balance	$ 42,069	$ 69,134	$ 25,025
Net other comprehensive (loss) income	68,570	(42,184)	26,564
Ending balance	85,580	42,069	69,134
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(23,336)	(22,312)	(7,225)
Net other comprehensive (loss) income	134	(1,024)	(15,087)
Ending balance	(23,202)	(23,336)	(22,312)
Unrealized gain (loss) on marketable securities, net
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(229)	(345)	(198)
Net other comprehensive (loss) income	165	116	(147)
Ending balance	(64)	(229)	(345)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(23,565)	(22,657)	(7,423)
Ending balance	$ (23,266)	$ (23,565)	$ (22,657)

Comprehensive Income (Loss) (98

Comprehensive Income (Loss) (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Unrealized gain (loss) on marketable securities, tax	$ 28	$ 16	$ (20)

Company Operations by Product99

Company Operations by Product, Customer and Geographic Area - Revenue by Product (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total product sales and services	$ 172,841	$ 147,222	$ 172,288
License and research revenue	404	3,024	721
Total revenue	173,245	150,246	173,009
Bloxiverz
Segment Reporting Information [Line Items]
Total product sales and services	45,596	82,896	150,083
Vazculep
Segment Reporting Information [Line Items]
Total product sales and services	38,187	39,796	20,151
Akovaz
Segment Reporting Information [Line Items]
Total product sales and services	80,617	16,831	0
Other
Segment Reporting Information [Line Items]
Total product sales and services	$ 8,441	$ 7,699	$ 2,054

Company Operations by Produc100

Company Operations by Product, Customer and Geographic Area - Revenue by Significant Customer (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total product sales and services	$ 172,841	$ 147,222	$ 172,288
License and research revenue	404	3,024	721
Total revenue	173,245	150,246	173,009
Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	172,841	147,222	172,288
License and research revenue		3,024	721
Total revenue	173,245	150,246	173,009
Customer A | Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	53,342	17,728	0
Customer B | Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	44,762	51,648	53,988
Customer C | Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	37,965	39,359	60,420
Customer D | Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	25,691	30,916	43,434
Others | Wholesaler Customer
Segment Reporting Information [Line Items]
Total product sales and services	$ 11,081	$ 7,571	$ 14,446

Company Operations by Produc101

Company Operations by Product, Customer and Geographic Area - Data by Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue by Geographic Region:
Total	$ 173,245	$ 150,246	$ 173,009
Long-lived Assets by Geographic Region:
Long-lived assets	120,153	44,747	37,090
United States
Revenue by Geographic Region:
Total	172,841	147,283	172,179
Long-lived Assets by Geographic Region:
Long-lived assets	116,536	42,021	34,515
France
Revenue by Geographic Region:
Total	0	0	89
Long-lived Assets by Geographic Region:
Long-lived assets	2,257	2,524	2,317
Ireland
Revenue by Geographic Region:
Total	404	2,963	741
Long-lived Assets by Geographic Region:
Long-lived assets	$ 1,360	$ 202	$ 258

Company Operations by Produc102

Company Operations by Product, Customer and Geographic Area (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)
Segment Reporting [Abstract]
Number of segments | segment	1
Concentration Risk [Line Items]
Accounts receivable	$ 14,785	$ 17,839
Accounts Receivable | Customer Concentration Risk | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	31.00%
Accounts receivable	$ 4,550
Accounts Receivable | Customer Concentration Risk | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	26.00%
Accounts receivable	$ 3,772
Accounts Receivable | Customer Concentration Risk | Customer Three
Concentration Risk [Line Items]
Concentration risk, percentage	23.00%
Accounts receivable	$ 3,395

Related Party Transactions (Det

Related Party Transactions (Details Textual) - USD ($)	Feb. 05, 2016	Dec. 03, 2013	Mar. 13, 2012	Jan. 31, 2021	Feb. 29, 2016	Dec. 31, 2013	Feb. 28, 2013	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Payments to acquire businesses, gross								$ 37,311,000	$ 30,838,000	$ 27,897,000
Percentage of royalty payable on net sales						0.834%
Royalty Arrangement
Related Party Transaction [Line Items]
Debt repayment term date		Dec. 31, 2024					Dec. 31, 2024
Long-term debt repayment percentage		0.834%					1.75%
Eclat Pharmaceuticals
Related Party Transaction [Line Items]
Warrants issued			2						2	2
Number of securities called by warrants (in shares)			3,300						3,300,000	3,300,000
Percentage of earn out payment									20.00%	20.00%
Affiliated Entity | Deerfield CSF LLC
Related Party Transaction [Line Items]
Percentage of royalty payable on net sales							1.75%
Affiliated Entity | Deerfield CSF LLC | FSC
Related Party Transaction [Line Items]
Payments to acquire businesses, gross	$ 1,050,000				$ 1,050,000
Debt instrument, term (in years)	5 years				5 years
Percentage of royalty payable on net sales	15.00%				15.00%
Scenario, Forecast | Affiliated Entity | Deerfield CSF LLC | FSC
Related Party Transaction [Line Items]
Final payment to acquire business gross				$ 15,000,000
Total payments to acquire business gross				$ 20,250,000
Maximum | Affiliated Entity | Deerfield CSF LLC | FSC
Related Party Transaction [Line Items]
Royalty guarantees, commitments, amount	$ 12,500,000
Royalty guarantees, commitments, term (in years)	10 years				10 years

Subsequent Event (Details Textu

Subsequent Event (Details Textual)	Feb. 14, 2018USD ($)	Feb. 12, 2018USD ($)	Jan. 31, 2021USD ($)	Dec. 31, 2013	Mar. 12, 2018$ / sharesshares	Feb. 23, 2018shares	Feb. 22, 2018USD ($)shares	Feb. 13, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Mar. 13, 2012$ / shares	Mar. 12, 2012shares
Subsequent Event [Line Items]
Number of securities called by each warrant (in shares) | shares									1
Percentage of royalty payable on net sales				0.834%
Subsequent event
Subsequent Event [Line Items]
ADS purchased, shares | shares								2,000,000
ADS purchased								$ 18,000,000
ADS purchased, in dollars per share | $ / shares								$ 8.99
ADS option price, in dollars per share | $ / shares								$ 10.79
ADS premium percentage								20.00%
Exchangeable Senior Notes Due 2023 | Subsequent event
Subsequent Event [Line Items]
Aggregate principal amount	$ 125,000,000
Interest rate	4.50%
Option to increase aggregate principal amount	$ 18,750,000
Net proceeds from the Note	137,719,000
Minimum denominations	200,000
In excess thereof minimum denominations	$ 1,000
ADSs exchange rate	92.6956
Discontinued operations, disposed of by sale | 2016 MIPA
Subsequent Event [Line Items]
Guaranty liability									$ 800,000
Discontinued operations, disposed of by sale | 2016 MIPA | Subsequent event
Subsequent Event [Line Items]
Interest payment		$ 263,000
Total remaining payment obligation		2,625,000
Repayments of debt			$ 15,263,000
Research and development reimbursement, in excess of		$ 1,000,000
FSC | Discontinued operations, disposed of by sale | 2016 MIPA | Subsequent event
Subsequent Event [Line Items]
Percentage of royalty payable on net sales		15.00%
Royalty payable on net sales, maximum		$ 10,300,000
Eclat Pharmaceuticals
Subsequent Event [Line Items]
Number of securities called by each warrant (in shares) | shares											1,100
Exercise price of warrants (in usd per share) | $ / shares										$ 11
Eclat Pharmaceuticals | Subsequent event
Subsequent Event [Line Items]
Number of securities called by each warrant (in shares) | shares							2,200
Warrant Settlement Cash							$ 2,911,000
Issuance of ADS | shares							603
Remaining warrants outstanding expired | shares					1,100
Exercise price of warrants (in usd per share) | $ / shares					$ 11
Eclat Pharmaceuticals | Exercise Price 1
Subsequent Event [Line Items]
Number of securities called by each warrant (in shares) | shares											2,200
Exercise price of warrants (in usd per share) | $ / shares										$ 7.44
Eclat Pharmaceuticals | Exercise Price 1 | Subsequent event
Subsequent Event [Line Items]
Number of securities called by each warrant (in shares) | shares						2,200

Schedule II - Valuation and 105

Schedule II - Valuation and Qualifying Accounts (Details) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 7,599	$ 45,516	$ 57,980
Additions: Charges to expense	391	6,873	4,312
Deductions	(664)	(42,417)	(11,737)
Other changes	8,028	(2,373)	(5,039)
Balance at end of period	$ 15,354	$ 7,599	$ 45,516