Impax Laboratories (IPXL) 10-Q 10 May 16 2016 Q1 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - shares	3 Months Ended
	Mar. 31, 2016	May. 06, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	IMPAX LABORATORIES INC
Trading Symbol	ipxl
Entity Central Index Key	1,003,642
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus (i.e. Q1,Q2,Q3,FY)	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		73,814,326
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

CONSOLIDATED BALANCE SHEETS (un

CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 412,178	$ 340,351
Accounts receivable, net	214,448	324,451
Inventory, net	133,563	125,582
Prepaid expenses and other current assets	22,185	31,689
Total current assets	782,374	822,073
Property, plant and equipment, net	219,400	214,156
Intangible assets, net	596,752	602,020
Goodwill	208,382	210,166
Deferred income taxes	284	315
Other non-current assets	79,107	73,757
Total assets	1,886,299	1,922,487
Current liabilities:
Accounts payable	50,724	56,325
Accrued expenses	213,112	204,711
Accrued profit sharing and royalty expenses	38,709	65,725
Total current liabilities	302,545	326,761
Long-term debt, net	429,878	424,595
Deferred income taxes	47,464	72,770
Other non-current liabilities	36,986	35,952
Total liabilities	$ 816,873	$ 860,078
Commitments and contingencies (Notes 20 and 21)
Stockholders’ equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; No shares issued or outstanding at March 31, 2016 and December 31, 2015	$ 0	$ 0
Common stock, $0.01 par value, 150,000,000 shares authorized; 73,339,655 issued and 73,095,926 outstanding shares at March 31, 2016; 72,926,205 issued and 72,682,476 outstanding shares at December 31, 2015	733	729
Treasury stock at cost: 243,729 shares at March 31, 2016 and December 31, 2015	(2,157)	(2,157)
Additional paid-in capital	518,455	504,077
Retained earnings	559,815	570,223
Accumulated other comprehensive loss	(7,420)	(10,463)
Total stockholders’ equity	1,069,426	1,062,409
Total liabilities and stockholders' equity	$ 1,886,299	$ 1,922,487

CONSOLIDATED BALANCE SHEETS (U3

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	73,339,655	72,926,205
Common stock, shares outstanding	73,095,926	72,682,476
Treasury stock, shares	243,729	243,729

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues:
Total revenues	$ 225,508	$ 143,096
Cost of revenues	122,918	83,862
Gross profit	102,590	59,234
Operating expenses:
Selling, general and administrative	44,298	50,160
Research and development	19,022	14,962
Patent litigation	1,319	960
Total operating expenses	64,639	66,082
Income (loss) from operations	37,951	(6,848)
Other income (expense):
Interest expense	(8,331)	(3,975)
Interest income	333	284
Reserve for Turing receivable	(48,043)	0
Other, net	596	(166)
Income (loss) before income taxes	(17,494)	(10,705)
Benefit from income taxes	(7,086)	(4,372)
Net loss	$ (10,408)	$ (6,333)
Net loss per common share:
Basic (in Dollars per share)	$ (0.15)	$ (0.09)
Diluted (in Dollars per share)	$ (0.15)	$ (0.09)
Weighted-average common shares outstanding:
Basic (in Shares)	70,665,394	68,967,875
Diluted (in Shares)	70,665,394	68,967,875
Impax Generics, net
Revenues:
Total revenues	$ 170,079	$ 128,741
Impax Specialty Pharma, net
Revenues:
Total revenues	55,429	$ 14,355
Turing Pharmaceuticals AG
Other income (expense):
Reserve for Turing receivable	(48,043)
Benefit from income taxes	$ (17,400)

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Income (Loss) Attributable to Parent
Net loss	$ (10,408)	$ (6,333)
Other comprehensive loss component:
Currency translation adjustment	3,043	2,900
Comprehensive loss	$ (7,365)	$ (3,433)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (10,408)	$ (6,333)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	15,720	10,442
Non-cash interest expense	5,305	0
Share-based compensation expense	7,278	6,488
Tax benefit from employees’ exercises of stock options and vestings of restricted stock awards	(445)	(660)
Deferred income taxes - net and uncertain tax positions	(12,078)	(668)
Accrued profit sharing and royalty expenses, net of payments	(27,016)	5,318
Reserve for Turing receivable	48,043	0
Provision for inventory reserves	6,777	(822)
Deferred revenue, net of revenue recognized	0	2,290
Other	0	(81)
Changes in certain assets and liabilities:
Accounts receivable	61,960	21,637
Inventory	(20,020)	(4,880)
Prepaid expenses and other assets	(1,572)	(10,048)
Accounts payable and accrued expenses	2,178	(1,631)
Other liabilities	1,735	2,605
Net cash provided by operating activities	77,457	23,657
Cash flows from investing activities:
Payment for business acquisition, net of cash acquired	0	(697,183)
Proceeds from sale of intangible assets	0	4,000
Purchases of property, plant and equipment	(10,882)	(4,223)
Payments for licensing agreements	(3,500)	0
Maturities of short-term investments	0	200,064
Net cash used in investing activities	(14,382)	(497,342)
Cash flows from financing activities:
Proceeds from issuance of term loan	0	435,000
Payment of deferred financing fees	0	(17,831)
Tax benefit from employees’ exercises of stock options and vestings of restricted stock awards	445	660
Proceeds from exercises of stock options and ESPP	7,662	3,065
Net cash provided by financing activities	8,107	420,894
Effect of exchange rate changes on cash and cash equivalents	645	1,011
Net increase (decrease) in cash and cash equivalents	71,827	(51,780)
Cash and cash equivalents, beginning of period	340,351	214,873
Cash and cash equivalents, end of period	412,178	163,093
Supplemental disclosure of cash flow information:
Cash paid for interest	7	2,317
Cash paid for income taxes	$ 2,475	$ 6,615

DESCRIPTION OF BUSINESS

DESCRIPTION OF BUSINESS	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS Impax Laboratories, Inc. (“Impax” or the “Company”) is a specialty pharmaceutical company that focuses on developing, manufacturing, marketing and distributing generic and branded pharmaceutical products. The Company has two reportable segments, referred to as “Impax Generics” and “Impax Specialty Pharma.” The Impax Generics division focuses on a broad range of therapeutic areas, including products having technically challenging drug-delivery mechanisms or unique product formulations. In addition to developing solid oral dosage products, the Impax Generics division’s portfolio includes alternative dosage form products, primarily through alliance and collaboration agreements with third parties. The Company’s Impax Specialty Pharma division is focused on the development and promotion, through the Company’s specialty sales force, of proprietary branded pharmaceutical products for the treatment of central nervous system (“CNS”) disorders and other select specialty segments. Tower Acquisition On March 9, 2015, Impax completed its acquisition of Tower Holdings, Inc. (“Tower”), including its operating subsidiaries CorePharma LLC (“CorePharma”) and Amedra Pharmaceuticals LLC (“Amedra Pharmaceuticals”), and Lineage Therapeutics Inc. (“Lineage”) for a purchase price of $691.3 million , net of $41.5 million of cash acquired and including the repayment of indebtedness of Tower and Lineage and post-closing working capital adjustments (collectively, the “Tower acquisition”). The privately-held companies specialized in the development, manufacture and commercialization of complex generic and branded pharmaceutical products. For additional information on the acquisition and the related financing of the acquisition, refer to “Note 2. Business Acquisition” and “Note 13. Debt.” Operating and Reporting Structure The Company currently operates in two divisions: the Impax Generics division and the Impax Specialty Pharma division. The Impax Generics division includes the Company’s legacy Global Pharmaceuticals business as well as the acquired CorePharma and Lineage businesses from the Tower acquisition. The Impax Specialty Pharma division includes the legacy Impax Pharmaceuticals business as well as the acquired Amedra Pharmaceuticals business from the Tower acquisition. Impax Generics develops, manufactures, sells, and distributes generic pharmaceutical products primarily through the following four sales channels: the “Impax Generics” sales channel, for generic pharmaceutical prescription products the Company sells directly to wholesalers, large retail drug chains, and others; the “Private Label” sales channel, for generic pharmaceutical over-the-counter (“OTC”) and prescription products the Company sells to unrelated third-party customers who, in turn, sell the product to third parties under their own label; the “Rx Partner” sales channel, for generic prescription products sold through unrelated third-party pharmaceutical entities under their own label pursuant to alliance agreements; and the “OTC Partner” sales channel, for generic pharmaceutical OTC products sold through unrelated third-party pharmaceutical entities under their own labels pursuant to alliance and supply agreements. Revenues from the “Impax Generics” sales channel and the “Private Label” sales channel are reported under the caption “Impax Generics sales, net” in “Note 23. Supplementary Financial Information.” The Company also generates revenue in Impax Generics from research and development services provided under a joint development agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” The Company provides these services through the research and development group in Impax Generics. Revenues from the “OTC Partner” sales channel are also reported under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma is engaged in the development, sale and distribution of proprietary branded pharmaceutical products that the Company believes represent improvements to already-approved pharmaceutical products addressing CNS disorders and other select specialty segments. Impax Specialty Pharma currently has one internally developed branded pharmaceutical product, Rytary® (IPX066), an extended release oral capsule formulation of carbidopa-levodopa for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication and/or manganese intoxication, which was approved by the FDA on January 7, 2015 and which the Company began marketing in the United States in April 2015. The Company received marketing authorization from the European Commission for NUMIENT™ (the brand name of IPX066 outside of the United States) during the fourth quarter of fiscal year 2015. In addition to Rytary®, Impax Specialty Pharma is also currently engaged in the sale and distribution of four other branded products; the more significant include Zomig® (zolmitriptan) products, indicated for the treatment of migraine headaches, under the terms of a Distribution, License, Development and Supply Agreement with AstraZeneca UK Limited (“AstraZeneca”) in the United States and in certain U.S. territories (the "AZ Agreement"), and EMVERM TM (mebendazole) 100 mg chewable tablets, indicated for the treatment of pinworm, whipworm, common roundworm, common hookworm, and American hookworm in single or mixed infections. Revenues from Impax-labeled branded products are reported under the caption “Impax Specialty Pharma sales, net” in “Note 23. Supplementary Financial Information.” Finally, the Company generates revenue in Impax Specialty Pharma from research and development services provided under a development and license agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma also has a number of product candidates that are in varying stages of development. See “Note 22. Segment Information,” for financial information about our segments for the three months ended March 31, 2016 and 2015. The Company owns and/or leases facilities in California, Pennsylvania, New Jersey and Taiwan, Republic of China (“R.O.C.”). In California, the Company utilizes a combination of owned and leased facilities mainly located in Hayward. The Company’s primary properties in California consist of a leased office building used as the Company’s corporate headquarters, in addition to five properties it owns, including a research and development center facility and a manufacturing facility. Additionally, the Company leases two facilities in Hayward, utilized for additional research and development, equipment storage and quality assurance support. In Pennsylvania, the Company leases facilities in New Britain and Montgomeryville used for sales and marketing, finance, and administrative personnel. In addition, the Company previously owned a packaging plant in Philadelphia, PA that was closed and sold in February 2016 in conjunction with the Company's restructuring of its packaging and distribution operations announced in June 2015 and discussed below in "Note 17. Restructurings". In New Jersey, the Company leases manufacturing, packaging, research and development and warehousing facilities in Middlesex, New Jersey and office space in Bridgewater, New Jersey. Outside the United States, in Taiwan, R.O.C., the Company owns a manufacturing facility. BASIS OF PRESENTATION Interim Financial Statements The accompanying unaudited interim consolidated financial statements have been prepared from the books and records of the Company in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and Rule10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission (“SEC”), which permit reduced disclosures for interim periods. All adjustments necessary for a fair presentation of the accompanying balance sheets and statements of operations, comprehensive loss, and cash flows have been made. Although these interim consolidated financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows are not necessarily indicative of the results that may be expected for the full year. Unaudited interim consolidated financial statements and footnotes should be read in conjunction with the audited consolidated financial statements and footnotes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2015, as filed with the SEC, wherein a more complete discussion of significant accounting policies and certain other information can be found. Principles of Consolidation The Company's unaudited interim consolidated financial statements include the accounts of the operating parent company, Impax Laboratories, Inc., its wholly owned subsidiaries, including Impax Laboratories USA, LLC, Impax Laboratories (Taiwan), Inc., ThoRx Laboratories, Inc., Impax International Holdings, Inc., Impax Holdings, LLC, Impax Laboratories (Netherlands) C.V., Impax Laboratories (Netherlands) B.V., Impax Laboratories Ireland Limited, Lineage and Tower, including operating subsidiaries CorePharma, Amedra Pharmaceuticals, Mountain LLC and Trail Services, Inc., in addition to an equity investment in Prohealth Biotech (Taiwan), Inc. (“Prohealth”), in which the Company held a 57.54% majority ownership interest at March 31, 2016 . All significant intercompany accounts and transactions have been eliminated. Foreign Currency Translation The Company translates the assets and liabilities of the Taiwan dollar functional currency of its majority-owned affiliate Prohealth and its wholly-owned subsidiary Impax Laboratories (Taiwan), Inc. into the U.S. dollar reporting currency using exchange rates in effect at the end of each reporting period. The revenues and expenses of these entities are translated using an average of the rates in effect during the reporting period. Gains and losses from these translations are recorded as currency translation adjustments included in the consolidated statements of comprehensive loss. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP and the rules and regulations of the SEC requires the use of estimates and assumptions, based on complex judgments considered reasonable, which affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The most significant judgments are employed in estimates used in determining values of tangible and intangible assets, legal contingencies, tax assets and tax liabilities, fair value of share-based compensation related to equity incentive awards issued to employees and directors, and estimates used in applying the Company’s revenue recognition policy, including those related to accrued chargebacks, rebates, product returns, Medicare, Medicaid, and other government rebate programs, shelf-stock adjustments, and the timing and amount of deferred and recognized revenue and deferred and amortized product manufacturing costs related to alliance and collaboration agreements. Actual results may differ from estimated results. Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation.

BUSINESS ACQUISITION

BUSINESS ACQUISITION	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
BUSINESS ACQUISITION	BUSINESS ACQUISITION On March 9, 2015, the Company completed the Tower acquisition, which included the acquisition of all of the outstanding shares of common stock of Tower and Lineage, pursuant to the Stock Purchase Agreement dated as of October 8, 2014, by and among the Company, Tower, Lineage, Roundtable Healthcare Partners II, L.P., Roundtable Healthcare Investors II, L.P., and the other parties thereto, including holders of certain options and warrants to acquire the common stock of Tower or Lineage. In connection with the Tower acquisition, all of the options and warrants of Tower and Lineage that were outstanding at the time of the acquisition were cancelled. The total consideration paid for Tower and Lineage was $691.3 million , net of $41.5 million of cash acquired and including the repayment of indebtedness of Tower and Lineage and post-closing working capital adjustments. The Company incurred total acquisition-related costs of $10.9 million , of which $5.7 million were incurred during the three months ended March 31, 2015 and included in selling, general and administrative expenses in the Company’s consolidated statement of operations for that period. In connection with the Tower acquisition, the Company recorded an accrual for severance and related termination costs of $2.4 million during 2015 related to the elimination of approximately 10 positions at the acquired companies. As of March 31, 2016 , less than $0.1 million remains to be paid and the Company currently expects this balance to be paid during the second quarter of 2016. The Tower acquisition allows the Company to expand its commercialized generic and branded product portfolios. The Company also leverages its sales and marketing organization to promote the marketed products acquired. Consideration The Company has accounted for the Tower acquisition as a business combination under the acquisition method of accounting. The Company has allocated the purchase price for the transaction based upon the fair value of net assets acquired and liabilities assumed at the date of acquisition. Recognition and Measurement of Assets Acquired and Liabilities Assumed at Fair Value The following tables summarize the final fair values of the tangible and identifiable intangible assets acquired and liabilities assumed in the transaction at the acquisition date, net of cash acquired of $41.5 million (in thousands): Accounts receivable (1) $ 56,851 Inventory 31,259 Income tax receivable and other prepaid expenses 2,407 Deferred income taxes 37,041 Property, plant and equipment 27,540 Intangible assets 632,600 Intangible assets held for sale 4,000 Goodwill 180,808 Other non-current assets 3,844 Total assets assumed 976,350 Current liabilities 67,706 Other non-current liabilities 7,291 Deferred tax liabilities 210,005 Total liabilities assumed 285,002 Cash paid, net of cash acquired (2) $ 691,348 (1) The accounts receivable acquired in the Tower acquisition had a fair value of $56.9 million , net of an allowance for doubtful accounts of $9.0 million , which represented the Company’s best estimate on March 9, 2015 (the closing date of the transaction) of the contractual cash flows not expected to be collected by the acquired companies. (2) The initial net purchase price of $697.2 million was subject to post-closing working capital adjustments, which resulted in the return of $5.9 million to the Company during the third quarter of 2015. Intangible Assets The following table identifies the Company’s allocations, by category, of the Tower purchase price to the intangible assets acquired: Estimated Fair Weighted-Average (years) Currently marketed product rights $ 381,100 13 Current and future royalty rights 80,800 12 In-process research and development product rights 170,700 n/a Total intangible assets $ 632,600 12 The estimated fair value of the in-process research and development and identifiable intangible assets was determined using the “income approach,” which is a valuation technique that provides an estimate of the fair value of an asset based on market participant expectations of the cash flows an asset would generate over its remaining useful life. Some of the more significant assumptions inherent in the development of those asset valuations include the estimated net cash flows for each year for each asset or product (including net revenues, cost of sales, research and development costs, selling and marketing costs and working capital/asset contributory asset charges), the appropriate discount rate to select in order to measure the risk inherent in each future cash flow stream, the assessment of each asset’s life cycle, the potential regulatory and commercial success risks, competitive trends impacting the asset and each cash flow stream as well as other factors. The discount rates used to arrive at the present value at the acquisition date of currently marketed products was 15% . For in-process research and development, the discount rate used was 16% to reflect the internal rate of return and incremental commercial uncertainty in the cash flow projections. No assurances can be given that the underlying assumptions used to prepare the discounted cash flow analysis will not change. For these and other reasons, actual results may vary significantly from estimated results. Goodwill The Company recorded $180.8 million of goodwill in connection with the Tower acquisition, some of which will not be tax-deductible. Goodwill of $59.7 million was assigned to the Impax Specialty Pharma segment and $121.1 million was assigned to the Impax Generics segment. Factors that contributed to the Company’s recognition of goodwill include the Company’s intent to expand its generic and branded pharmaceutical product portfolios and to acquire certain benefits from the Tower and Lineage product pipelines in addition to the anticipated synergies that the Company expects to generate from the acquisition. Unaudited Pro Forma Results of Operations The following table reflects the unaudited pro forma combined results of operations for the three months ended March 31, 2015 (assuming the closing of the Tower acquisition occurred on January 1, 2014) (in thousands): Three Months Ended March 31, 2015 Total revenues $ 175,533 Net loss $ (6,595 ) The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the actual results of operations had the closing of the transaction taken place on January 1, 2014. Furthermore, the pro forma results do not purport to project the future results of operations of the Company. The unaudited pro forma information reflects primarily the following adjustments: • Adjustments to amortization expense related to identifiable intangible assets acquired; • Adjustments to depreciation expense related to property, plant and equipment acquired; • Adjustments to interest expense to reflect the long-term debt held by Tower and Lineage paid out and eliminated at the closing and the Company's Senior Secured Credit Facilities with Barclays Bank PLC (described in "Note 13. Debt" below); • Adjustments to cost of revenues related to the fair value adjustments in inventory sold including elimination of $1 million for the three months ended March 31, 2015; • Adjustments to selling, general and administrative expense related to severance and retention costs of $3 million incurred as part of the transaction. These costs were eliminated in the pro forma results for the three months ended March 31, 2015; • Adjustments to selling, general and administrative expense related to transaction costs directly attributable to the transaction include the elimination of $12 million of charges in the pro forma results for the three month period ended March 31, 2015; and • Adjustments to reflect the elimination of $2.3 million in commitment fees related to the Company's $435 million term loan with Barclays Bank PLC (described in "Note 13. Debt" below) that were incurred during the three months ended March 31, 2015. All of the items above were adjusted for the applicable tax impact.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS Impax Laboratories, Inc. (“Impax” or the “Company”) is a specialty pharmaceutical company that focuses on developing, manufacturing, marketing and distributing generic and branded pharmaceutical products. The Company has two reportable segments, referred to as “Impax Generics” and “Impax Specialty Pharma.” The Impax Generics division focuses on a broad range of therapeutic areas, including products having technically challenging drug-delivery mechanisms or unique product formulations. In addition to developing solid oral dosage products, the Impax Generics division’s portfolio includes alternative dosage form products, primarily through alliance and collaboration agreements with third parties. The Company’s Impax Specialty Pharma division is focused on the development and promotion, through the Company’s specialty sales force, of proprietary branded pharmaceutical products for the treatment of central nervous system (“CNS”) disorders and other select specialty segments. Tower Acquisition On March 9, 2015, Impax completed its acquisition of Tower Holdings, Inc. (“Tower”), including its operating subsidiaries CorePharma LLC (“CorePharma”) and Amedra Pharmaceuticals LLC (“Amedra Pharmaceuticals”), and Lineage Therapeutics Inc. (“Lineage”) for a purchase price of $691.3 million , net of $41.5 million of cash acquired and including the repayment of indebtedness of Tower and Lineage and post-closing working capital adjustments (collectively, the “Tower acquisition”). The privately-held companies specialized in the development, manufacture and commercialization of complex generic and branded pharmaceutical products. For additional information on the acquisition and the related financing of the acquisition, refer to “Note 2. Business Acquisition” and “Note 13. Debt.” Operating and Reporting Structure The Company currently operates in two divisions: the Impax Generics division and the Impax Specialty Pharma division. The Impax Generics division includes the Company’s legacy Global Pharmaceuticals business as well as the acquired CorePharma and Lineage businesses from the Tower acquisition. The Impax Specialty Pharma division includes the legacy Impax Pharmaceuticals business as well as the acquired Amedra Pharmaceuticals business from the Tower acquisition. Impax Generics develops, manufactures, sells, and distributes generic pharmaceutical products primarily through the following four sales channels: the “Impax Generics” sales channel, for generic pharmaceutical prescription products the Company sells directly to wholesalers, large retail drug chains, and others; the “Private Label” sales channel, for generic pharmaceutical over-the-counter (“OTC”) and prescription products the Company sells to unrelated third-party customers who, in turn, sell the product to third parties under their own label; the “Rx Partner” sales channel, for generic prescription products sold through unrelated third-party pharmaceutical entities under their own label pursuant to alliance agreements; and the “OTC Partner” sales channel, for generic pharmaceutical OTC products sold through unrelated third-party pharmaceutical entities under their own labels pursuant to alliance and supply agreements. Revenues from the “Impax Generics” sales channel and the “Private Label” sales channel are reported under the caption “Impax Generics sales, net” in “Note 23. Supplementary Financial Information.” The Company also generates revenue in Impax Generics from research and development services provided under a joint development agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” The Company provides these services through the research and development group in Impax Generics. Revenues from the “OTC Partner” sales channel are also reported under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma is engaged in the development, sale and distribution of proprietary branded pharmaceutical products that the Company believes represent improvements to already-approved pharmaceutical products addressing CNS disorders and other select specialty segments. Impax Specialty Pharma currently has one internally developed branded pharmaceutical product, Rytary® (IPX066), an extended release oral capsule formulation of carbidopa-levodopa for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication and/or manganese intoxication, which was approved by the FDA on January 7, 2015 and which the Company began marketing in the United States in April 2015. The Company received marketing authorization from the European Commission for NUMIENT™ (the brand name of IPX066 outside of the United States) during the fourth quarter of fiscal year 2015. In addition to Rytary®, Impax Specialty Pharma is also currently engaged in the sale and distribution of four other branded products; the more significant include Zomig® (zolmitriptan) products, indicated for the treatment of migraine headaches, under the terms of a Distribution, License, Development and Supply Agreement with AstraZeneca UK Limited (“AstraZeneca”) in the United States and in certain U.S. territories (the "AZ Agreement"), and EMVERM TM (mebendazole) 100 mg chewable tablets, indicated for the treatment of pinworm, whipworm, common roundworm, common hookworm, and American hookworm in single or mixed infections. Revenues from Impax-labeled branded products are reported under the caption “Impax Specialty Pharma sales, net” in “Note 23. Supplementary Financial Information.” Finally, the Company generates revenue in Impax Specialty Pharma from research and development services provided under a development and license agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma also has a number of product candidates that are in varying stages of development. See “Note 22. Segment Information,” for financial information about our segments for the three months ended March 31, 2016 and 2015. The Company owns and/or leases facilities in California, Pennsylvania, New Jersey and Taiwan, Republic of China (“R.O.C.”). In California, the Company utilizes a combination of owned and leased facilities mainly located in Hayward. The Company’s primary properties in California consist of a leased office building used as the Company’s corporate headquarters, in addition to five properties it owns, including a research and development center facility and a manufacturing facility. Additionally, the Company leases two facilities in Hayward, utilized for additional research and development, equipment storage and quality assurance support. In Pennsylvania, the Company leases facilities in New Britain and Montgomeryville used for sales and marketing, finance, and administrative personnel. In addition, the Company previously owned a packaging plant in Philadelphia, PA that was closed and sold in February 2016 in conjunction with the Company's restructuring of its packaging and distribution operations announced in June 2015 and discussed below in "Note 17. Restructurings". In New Jersey, the Company leases manufacturing, packaging, research and development and warehousing facilities in Middlesex, New Jersey and office space in Bridgewater, New Jersey. Outside the United States, in Taiwan, R.O.C., the Company owns a manufacturing facility. BASIS OF PRESENTATION Interim Financial Statements The accompanying unaudited interim consolidated financial statements have been prepared from the books and records of the Company in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and Rule10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission (“SEC”), which permit reduced disclosures for interim periods. All adjustments necessary for a fair presentation of the accompanying balance sheets and statements of operations, comprehensive loss, and cash flows have been made. Although these interim consolidated financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows are not necessarily indicative of the results that may be expected for the full year. Unaudited interim consolidated financial statements and footnotes should be read in conjunction with the audited consolidated financial statements and footnotes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2015, as filed with the SEC, wherein a more complete discussion of significant accounting policies and certain other information can be found. Principles of Consolidation The Company's unaudited interim consolidated financial statements include the accounts of the operating parent company, Impax Laboratories, Inc., its wholly owned subsidiaries, including Impax Laboratories USA, LLC, Impax Laboratories (Taiwan), Inc., ThoRx Laboratories, Inc., Impax International Holdings, Inc., Impax Holdings, LLC, Impax Laboratories (Netherlands) C.V., Impax Laboratories (Netherlands) B.V., Impax Laboratories Ireland Limited, Lineage and Tower, including operating subsidiaries CorePharma, Amedra Pharmaceuticals, Mountain LLC and Trail Services, Inc., in addition to an equity investment in Prohealth Biotech (Taiwan), Inc. (“Prohealth”), in which the Company held a 57.54% majority ownership interest at March 31, 2016 . All significant intercompany accounts and transactions have been eliminated. Foreign Currency Translation The Company translates the assets and liabilities of the Taiwan dollar functional currency of its majority-owned affiliate Prohealth and its wholly-owned subsidiary Impax Laboratories (Taiwan), Inc. into the U.S. dollar reporting currency using exchange rates in effect at the end of each reporting period. The revenues and expenses of these entities are translated using an average of the rates in effect during the reporting period. Gains and losses from these translations are recorded as currency translation adjustments included in the consolidated statements of comprehensive loss. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP and the rules and regulations of the SEC requires the use of estimates and assumptions, based on complex judgments considered reasonable, which affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The most significant judgments are employed in estimates used in determining values of tangible and intangible assets, legal contingencies, tax assets and tax liabilities, fair value of share-based compensation related to equity incentive awards issued to employees and directors, and estimates used in applying the Company’s revenue recognition policy, including those related to accrued chargebacks, rebates, product returns, Medicare, Medicaid, and other government rebate programs, shelf-stock adjustments, and the timing and amount of deferred and recognized revenue and deferred and amortized product manufacturing costs related to alliance and collaboration agreements. Actual results may differ from estimated results. Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company's complete Summary of Significant Accounting Policies can be found in "Item 15. Exhibits and Financial Statement Schedules - Note 4. Summary of Significant Accounting Policies" in the Company's Annual Report on Form 10-K for the year ended December 31, 2015, as filed with the SEC. Certain significant accounting policies have been repeated below. Revenue Recognition The Company recognizes revenue when the earnings process is complete, which under SEC Staff Accounting Bulletin No. 104, Topic No. 13, “Revenue Recognition” (“SAB 104”), is when revenue is realized or realizable and earned, there is persuasive evidence a revenue arrangement exists, delivery of goods or services has occurred, the sales price is fixed or determinable, and collectability is reasonably assured. The Company accounts for material revenue arrangements which contain multiple deliverables in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 605-25, Revenue Recognition - Multiple-Element Arrangements ("ASC 605-25"), which addresses the determination of whether an arrangement involving multiple deliverables contains more than one unit of accounting. A delivered item within an arrangement is considered a separate unit of accounting only if both of the following criteria are met: • the delivered item has value to the customer on a stand-alone basis; and • if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially in the control of the vendor. Under ASC 605-25, if both of the criteria above are not met, then separate accounting for the individual deliverables is not appropriate. Revenue recognition for arrangements with multiple deliverables constituting a single unit of accounting is recognized generally over the greater of the term of the arrangement or the expected period of performance, either on a straight-line basis or on a modified proportional performance method. The Company accounts for milestones related to research and development activities in accordance with FASB ASC Topic 605-28, Revenue Recognition - Milestone Method ("ASC 605-28"). ASC 605-28 allows for the recognition of consideration, which is contingent on the achievement of a substantive milestone, in its entirety in the period the milestone is achieved. A milestone is considered to be substantive if all of the following criteria are met: • the milestone is commensurate with either (1) the performance required to achieve the milestone or (2) the enhancement of the value of the delivered items resulting from the performance required to achieve the milestone; • the milestone relates solely to past performance; and • the milestone payment is reasonable relative to all of the deliverables and payment terms within the agreement. Impax Generics revenues, net and Impax Specialty Pharma revenues, net The Impax Generics revenues, net and Impax Specialty Pharma revenues, net include revenue recognized related to shipments of generic and branded pharmaceutical products to the Company’s customers, primarily drug wholesalers and retail chains. Gross sales revenue is recognized at the time title and risk of loss passes to the customer, which is generally when product is received by the customer. Net revenues may include deductions from the gross sales price related to estimates for chargebacks, rebates, distribution service fees, returns, shelf-stock adjustments, and other pricing adjustments. The Company records an estimate for these deductions in the same period when revenue is recognized. A description of each of these gross-to-net deductions follows. • Chargebacks The Company has agreements establishing contract prices for certain products with certain indirect customers, such as managed care organizations, hospitals and government agencies who purchase products from drug wholesalers. The contract prices are lower than the prices the customer would otherwise pay to the wholesaler, and the price difference is referred to as a chargeback, which generally takes the form of a credit memo issued by the Company to reduce the invoiced gross selling price charged to the wholesaler. An estimated accrued provision for chargeback deductions is recognized at the time of product shipment. The primary factors considered when estimating the provision for chargebacks are the average historical chargeback credits given, the mix of products shipped, and the amount of inventory on hand at the major drug wholesalers with whom the Company does business. The Company also monitors actual chargebacks granted and compares them to the estimated provision for chargebacks to assess the reasonableness of the chargeback reserve at each quarterly balance sheet date. • Rebates The Company maintains various rebate programs with its customers in an effort to maintain a competitive position in the marketplace and to promote sales and customer loyalty. The rebates generally take the form of a credit memo to reduce the invoiced gross selling price charged to a customer for products shipped. An estimated accrued provision for rebate deductions is recognized at the time of product shipment. The primary factors the Company considers when estimating the provision for rebates are the average historical experience of aggregate credits issued, the mix of products shipped and the historical relationship of rebates as a percentage of total gross product sales, the contract terms and conditions of the various rebate programs in effect at the time of shipment, and the amount of inventory on hand at the major drug wholesalers with whom the Company does business. The Company also monitors actual rebates granted and compares them to the estimated provision for rebates to assess the reasonableness of the rebate reserve at each quarterly balance sheet date. • Distribution Service Fees The Company pays distribution service fees to several of its wholesaler customers related to sales of its Impax Products. The wholesalers are generally obligated to provide the Company with periodic outbound sales information as well as inventory levels of the Company’s Impax Products held in their warehouses. Additionally, the wholesalers have agreed to manage the variability of their purchases and inventory levels within specified days on hand limits. An accrued provision for distribution service fees is recognized at the time products are shipped to wholesalers. • Returns The Company allows its customers to return product if approved by authorized personnel in writing or by telephone with the lot number and expiration date accompanying any request and if such products are returned within six months prior to or until twelve months following, the product’s expiration date. The Company estimates and recognizes an accrued provision for product returns as a percentage of gross sales based upon historical experience. The product return reserve is estimated using a historical lag period, which is the time between when the product is sold and when it is ultimately returned, and estimated return rates which may be adjusted based on various assumptions including: changes to internal policies and procedures, business practices, commercial terms with customers, and the competitive position of each product; the amount of inventory in the wholesale and retail supply chain; the introduction of new products; and changes in market sales information. The Company also considers other factors, including significant market changes which may impact future expected returns and actual product returns. The Company monitors actual returns on a quarterly basis and may record specific provisions for returns it believes are not covered by historical percentages. • Shelf-Stock Adjustments Based upon competitive market conditions, the Company may reduce the selling price of certain Impax Generics division products. The Company may issue a credit against the sales amount to a customer based upon their remaining inventory of the product in question, provided the customer agrees to continue to make future purchases of product from the Company. This type of customer credit is referred to as a shelf-stock adjustment, which is the difference between the initial sales price and the revised lower sales price, multiplied by an estimate of the number of product units on hand at a given date. Decreases in selling prices are discretionary decisions made by the Company in response to market conditions, including estimated launch dates of competing products and declines in market price. The Company records an estimate for shelf-stock adjustments in the period it agrees to grant such a credit memo to a customer. • Cash Discounts The Company offers cash discounts to its customers, generally 2% to 3% of the gross selling price, as an incentive for paying within invoice terms, which generally range from 30 to 90 days. An estimate of cash discounts is recorded in the same period when revenue is recognized. • Medicaid and Other U.S. Government Pricing Programs As required by law, the Company provides a rebate on drugs dispensed under the Medicaid program, Medicare Part D, TRICARE, and other U.S. government pricing programs. The Company determines its estimated government rebate accrual primarily based on historical experience of claims submitted by the various states and other jurisdictions and any new information regarding changes in the various programs which may impact the Company’s estimate of government rebates. In determining the appropriate accrual amount, the Company considers historical payment rates and processing lag for outstanding claims and payments. The Company records estimates for government rebates as a deduction from gross sales, with a corresponding adjustment to accrued liabilities. • Rx Partner and OTC Partner The Rx Partner and OTC Partner contracts include revenue recognized under alliance and collaboration agreements between the Company and unrelated third-party pharmaceutical companies. The Company has entered into these alliance agreements to develop marketing and/or distribution relationships with its partners to fully leverage its technology platform. The Rx Partners and OTC Partners alliance agreements obligate the Company to deliver multiple goods and/or services over extended periods. Such deliverables include manufactured pharmaceutical products, exclusive and semi-exclusive marketing rights, distribution licenses, and research and development services. In exchange for these deliverables the Company receives payments from its agreement partners for product shipments and research and development services, and may also receive other payments including royalties, profit sharing payments, and upfront and periodic milestone payments. Revenue received from the alliance agreement partners for product shipments under these agreements is not subject to deductions for chargebacks, rebates, product returns, and other pricing adjustments. Royalty and profit sharing amounts the Company receives under these agreements are calculated by the respective agreement partner, with such royalty and profit share amounts generally based upon estimates of net product sales or gross profit which include estimates of deductions for chargebacks, rebates, product returns, and other adjustments the alliance agreement partners may negotiate with their respective customers. The Company records the agreement partner's adjustments to such estimated amounts in the period the agreement partner reports the amounts to the Company. The Company applies the guidance of ASC 605-25 to the Strategic Alliance Agreement, as amended, with Teva Pharmaceuticals Curacao N.V., a subsidiary of Teva Pharmaceutical Industries Limited (the “Teva Agreement”). The Company looks to the underlying delivery of goods and/or services which give rise to the payment of consideration under the Teva Agreement to determine the appropriate revenue recognition. The Company initially defers consideration received as a result of research and development-related activities performed under the Teva Agreement. The Company recognizes deferred revenue on a straight-line basis over the expected period of performance for such services. Consideration received as a result of the manufacture and delivery of products under the Teva Agreement is recognized at the time title and risk of loss passes to the customer, which is generally when product is received by Teva. The Company recognizes profit share revenue in the period earned. OTC Partner revenue is related to agreements with Pfizer, Inc., formerly Wyeth LLC (“Pfizer”) and L. Perrigo Company (“Perrigo”) with respect to the supply of over-the-counter pharmaceutical products. The OTC Partner sales channel is no longer a core area of the business, and the over-the-counter pharmaceutical products the Company sells through this sales channel are older products which are only sold to Pfizer and Perrigo. The Company is currently only required to manufacture the over-the-counter pharmaceutical products under its agreements with Pfizer and Perrigo. The Company recognizes profit share revenue in the period earned. • Research Partner The Research Partner contract revenue results from development agreements the Company enters into with unrelated third-party pharmaceutical companies. The development agreements generally obligate the Company to provide research and development services over multiple periods. In exchange for this service, the Company generally receives upfront payments upon signing of each development agreement and is eligible to receive contingent milestone payments, payment of which is based upon the achievement of contractually specified events. Additionally, the Company may also receive royalty payments from the sale, if any, of a successfully developed and commercialized product under one of these development agreements. The Company recognizes revenue received from the achievement of contingent research and development milestones in the period such payment is earned. Royalty revenue, if any, will be recognized as current period revenue when earned. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are cash, cash equivalents, and accounts receivable. The Company limits its credit risk associated with cash and cash equivalents by placing its investments with high quality money market funds, corporate debt, and short-term commercial paper and in securities backed by the U.S. Government. The Company limits its credit risk with respect to accounts receivable by performing credit evaluations when deemed necessary. The Company does not require collateral to secure amounts owed to it by its customers. In July 2015, the Company received an unsolicited offer from Turing Pharmaceuticals AG (“Turing”) to purchase the U.S. rights to Daraprim®, one of the marketed products acquired in the Tower acquisition, as well as the active pharmaceutical ingredient for the product and the finished goods inventory on hand. Pursuant to the terms of the Asset Purchase Agreement between the Company and Turing dated August 7, 2015 (the “Turing APA”), the Company also granted a limited license to sell the existing Daraprim® product under the Company’s labeler code with the Company’s trade dress. The sale closed on August 7, 2015. In accordance with the terms of the Turing APA and in accordance with federal laws and regulations, the Company received, and is initially responsible for processing and paying (subject to reimbursement by Turing), all chargebacks and rebates resulting from utilization by Medicaid, Medicare and other federal, state and local governmental programs, health plans and other health care providers for product sold under the Company’s labeler code. Under the terms of the Turing APA, Turing is responsible for liabilities related to chargebacks and rebates that arise as a result of Turing’s marketing or selling related activities in connection with Daraprim®. During the fourth quarter of 2015, the Company began receiving invoices for chargebacks from wholesalers and rebates from various state Medicaid agencies for Daraprim® purchases made by governmental agencies during the third quarter of 2015. As a result, the Company recorded a $40.6 million receivable from Turing as of December 31, 2015, representing actual invoices received related to the third quarter of 2015 and an estimate for invoices not yet received related to the third and fourth quarters of 2015. During the first quarter of 2016, the Company received additional invoices related to the third and fourth quarters of 2015 and recorded an estimate for invoices not yet received related to the first quarter of 2016. In total, the Company recorded an additional $7.4 million receivable from Turing during the three month period ended March 31, 2016 , resulting in an estimated accounts receivable balance due to the Company of $48.0 million as of March 31, 2016, with over $20 million of such amount representing overdue unpaid invoices due from Turing for chargebacks and Medicaid rebate liability as of March 31, 2016. The Company has also recorded as of March 31, 2016 an estimated accrued liability of $42.9 million for amounts owed to wholesalers, Medicaid and other governmental agencies for Daraprim®. The difference of $5.1 million represents payments made by the Company on Turing's behalf during the first quarter of 2016. As of May 6, 2016, the amount of total payments made by the Company on Turing’s behalf was $19.2 million . As a result of the uncertainty of the Company collecting the reimbursement amounts owed by Turing that has developed since the filing of the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015, the Company recorded a reserve in the amount of $48.0 million on the Company’s consolidated statement of operations in other income (expense) for the three month period ended March 31, 2016, representing the full amount of the estimated receivable due from Turing as of March 31, 2016. On May 2, 2016, the Company filed suit against Turing in the United States District Court for the Southern District of New York alleging breach of the terms of the Turing APA seeking (i) a declaratory judgment that the Company may revoke Turing’s right to sell Daraprim® under the Company’s labeler code and national drug codes; (ii) specific performance to require Turing to comply with its obligations under the Turing APA for past due reports and for reports going forward; and (iii) money damages to remedy Turing’s failure to reimburse the Company for in excess of $20 million of Medicaid rebate liability and for future amounts that may be due. If the Company receives an unfavorable outcome in its suit against Turing or if Turing for any reason does not, or is unable to, make its reimbursement payments to the Company, it could result in a material charge to the Company and could have a material adverse effect on the Company’s business, results of operation and financial condition.

FAIR VALUE MEASUREMENT AND FINA

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS	FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS The carrying values of cash equivalents, accounts receivable, prepaid expenses and other current assets, and accounts payable in the Company’s consolidated balance sheets approximated their fair values as of March 31, 2016 and December 31, 2015 due to their short-term nature. Certain of the Company’s financial instruments are measured at fair value using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: • Level 1 - Inputs are quoted prices for identical instruments in active markets. • Level 2 - Inputs are quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; or model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 - Inputs are unobservable and reflect the Company's own assumptions, based on the best information available, including the Company's own data. The carrying amounts and fair values of the Company’s financial instruments at March 31, 2016 and December 31, 2015 are indicated below (in thousands): As of March 31, 2016 Fair Value Measurement Based on Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Deferred Compensation Plan assets (1) $ 30,733 $ 30,733 $ — $ 30,733 $ — Liabilities 2% Convertible senior notes due June 2022 (2) $ 600,000 $ 536,472 $ 536,472 $ — $ — Deferred Compensation Plan liabilities (1) $ 27,766 $ 27,766 $ — $ 27,766 $ — As of December 31, 2015 Fair Value Measurement Based on Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Deferred Compensation Plan assets (1) $ 30,726 $ 30,726 $ — $ 30,726 $ — Liabilities 2% Convertible senior notes due June 2022 (2) $ 600,000 $ 602,250 $ 602,250 $ — $ — Deferred Compensation Plan liabilities (1) $ 25,581 $ 25,581 $ — $ 25,581 $ — (1) The Deferred Compensation Plan liabilities are non-current liabilities recorded at the value of the amount owed to the plan participants, with changes in value recognized as compensation expense in the Company’s consolidated statements of operations. The calculation of the Deferred Compensation Plan obligation is derived from observable market data by reference to hypothetical investments selected by the participants and is included in the line items captioned “Other non-current liabilities” on the Company’s consolidated balance sheets. The Company invests participant contributions in corporate-owned life insurance (“COLI”) policies, for which the cash surrender value is included in the line item captioned “Other non-current assets” on the Company’s consolidated balance sheets. (2) The difference between the amount shown as the carrying value in the above tables and the amount shown on the Company’s consolidated balance sheets at March 31, 2016 and December 31, 2015 represents the unaccreted discounts related to deferred debt issuance costs and bifurcation of the conversion feature of the notes.

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, “Revenue from Contracts with Customers” (Topic 606) regarding the accounting for and disclosures of revenue recognition, with an effective date for annual and interim periods beginning after December 15, 2016. This update provides a single comprehensive model for accounting for revenue from contracts with customers. The model requires that revenue recognized reflect the actual consideration to which the entity expects to be entitled in exchange for the goods or services defined in the contract, including in situations with multiple performance obligations. In July 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date”, which deferred the effective date, of the previously issued revenue recognition guidance by one year. The guidance will be effective for annual and interim periods beginning after December 15, 2017. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In July 2015, the FASB issued ASU 2015-11, Inventory (Topic 330): “Simplifying the Measurement of Inventory”, with guidance regarding the accounting for and measurement of inventory. The update requires that inventory measured using first-in, first-out (FIFO) shall be measured at the lower of cost and net realizable value. When there is evidence that the net realizable value of inventory is lower than its cost, the difference shall be recognized as a loss in earnings in the period in which it occurs. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In September 2015, the FASB issued ASU 2015-16, Business Combinations (Topic 805): “Simplifying the Accounting for Measurement-Period Adjustments”, with guidance regarding the accounting for and disclosure of measurement-period adjustments that occur in periods after a business combination is consummated. This update requires that the acquirer recognize measurement-period adjustments in the reporting period in which they are determined and, as such, eliminates the previous requirement to retrospectively account for these adjustments. This update also requires an entity to present separately on the face of the income statement, or disclose in the notes, the amount recorded in the current-period income statement that would have been recorded in previous reporting periods if the adjustments had been recognized as of the acquisition date. The effective date for annual and interim periods begins after December 15, 2015. The Company adopted this guidance during 2016, and it did not have a material effect on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), with guidance regarding the accounting for and disclosure of leases. The update requires lessees to recognize all leases, including operating leases, with a term greater than 12 months on the balance sheet. This update also requires lessees and lessors to disclose key information about their leasing transactions. The guidance will be effective for annual and interim periods beginning after December 15, 2018. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-06, Contingent Put and Call Options in Debt Instruments (Topic 815), with guidance regarding the accounting for embedded derivatives related to debt contracts. The update clarifies that determining whether the economic characteristics of a put or call are clearly and closely related to its debt host requires only an assessment of the four-step decision sequence outlined in FASB ASC paragraph 815-15-25-24. The update also indicates that entities are not required to separately assess whether the contingency itself is clearly and closely related. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting (Topic 718), with guidance regarding the simplification of accounting for share-based payment award transactions. The update changes the accounting for such areas as the accounting and cash flow classification for excess tax benefits and deficiencies; forfeitures; and tax withholding requirements and cash flow classification. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements.

SHORT-TERM INVESTMENTS

SHORT-TERM INVESTMENTS	3 Months Ended
	Mar. 31, 2016
Investments Schedule [Abstract]
SHORT-TERM INVESTMENTS	SHORT-TERM INVESTMENTS Prior to December 31, 2014, the Company invested its excess cash in high quality (AAA-rated) short-maturity marketable debt securities, such as commercial paper and corporate bonds. The Company historically held all of its investments in marketable debt securities until maturity. Accordingly, these investments were accounted for as “held-to-maturity” securities and were recorded at amortized cost, which approximated fair value. During the first quarter of 2015, the Company allowed all of its investments in marketable debt securities to mature. The proceeds from these maturities of $200.1 million were used to fund the Tower acquisition on March 9, 2015. The Company held no short-term investments as of March 31, 2016 and December 31, 2015 .

ACCOUNTS RECEIVABLE

ACCOUNTS RECEIVABLE	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
ACCOUNTS RECEIVABLE	ACCOUNTS RECEIVABLE The composition of accounts receivable, net is as follows (in thousands): March 31, 2016 December 31, 2015 Gross accounts receivable (1) $ 729,060 $ 738,730 Less: Rebate reserve (320,013 ) (265,229 ) Less: Chargeback reserve (104,293 ) (102,630 ) Less: Distribution services reserve (11,638 ) (12,576 ) Less: Discount reserve (15,469 ) (18,657 ) Less: Uncollectible accounts reserve (2) (63,199 ) (15,187 ) Accounts receivable, net $ 214,448 $ 324,451 (1) Includes estimated $48.0 million and $40.6 million as of March 31, 2016 and December 31, 2015, respectively, receivable due from Turing for reimbursement of Daraprim® chargebacks and Medicaid rebate liabilities. (2) As a result of the uncertainty of collection that has developed since the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2015, the Company recorded a reserve of $48.0 million as of March 31, 2016, which represents the full amount of the estimated receivable due from Turing as of that date. See "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" for additional information regarding the Turing receivable. A roll-forward of the rebate and chargeback reserves activity for the three months ended March 31, 2016 and the year ended December 31, 2015 is as follows (in thousands): Rebate reserve March 31, 2016 December 31, 2015 Beginning balance $ 265,229 $ 88,812 Acquired balances — 75,447 Provision recorded during the period for Impax Generics rebates 185,476 571,642 Credits issued during the period for Impax Generics rebates (130,692 ) (470,672 ) Ending balance $ 320,013 $ 265,229 The payment mechanisms for rebates in the Impax Generics and Impax Specialty Pharma divisions are different, which impacts the location on the Company's balance sheet. Impax Specialty Pharma rebates are classified as Accrued Expenses on the Company's consolidated balance sheets. Chargeback reserve March 31, 2016 December 31, 2015 Beginning balance $ 102,630 $ 43,125 Acquired balances — 24,532 Provision recorded during the period 223,465 833,157 Credits issued during the period (221,802 ) (798,184 ) Ending balance $ 104,293 $ 102,630

INVENTORY

INVENTORY	3 Months Ended
	Mar. 31, 2016
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory, net of carrying value reserves, at March 31, 2016 and December 31, 2015 consisted of the following (in thousands): March 31, 2016 December 31, 2015 Raw materials $ 57,065 $ 52,366 Work in-process 5,935 4,417 Finished goods 89,827 82,311 Total inventory 152,827 139,094 Less: Non-current inventory 19,264 13,512 Total current inventory $ 133,563 $ 125,582 Inventory carrying value reserves were $30.9 million and $24.1 million at March 31, 2016 and December 31, 2015 , respectively. The Company recognizes pre-launch inventories at the lower of its cost or the expected net selling price. Cost is determined using a standard cost method, which approximates actual cost, and assumes a FIFO flow of goods. Costs of unapproved products are the same as approved products and include materials, labor, quality control, and production overhead. When the Company concludes FDA approval is expected within approximately six months, the Company will generally begin to schedule manufacturing process validation studies as required by the FDA to demonstrate the production process can be scaled up to manufacture commercial batches. Consistent with industry practice, the Company may build quantities of pre-launch inventories of certain products pending required final FDA approval and/or resolution of patent infringement litigation, when, in the Company’s assessment, such action is appropriate to prepare for the anticipated commercial launch, FDA approval is expected in the near term, and/or the related litigation will be resolved in the Company’s favor. The capitalization of unapproved pre-launch inventory involves risks, including, among other items, FDA approval of product may not occur; approvals may require additional or different testing and/or specifications than used for unapproved inventory; and, in cases where the unapproved inventory is for a product subject to litigation, the litigation may not be resolved or settled in favor of the Company. If any of these risks were to materialize and the launch of the unapproved product delayed or prevented, then the net carrying value of unapproved inventory may be partially or fully reserved. Generally, the selling price of a generic pharmaceutical product is at discount from the corresponding brand product selling price. Typically, a generic drug is easily substituted for the corresponding branded product, and once a generic product is approved, the pre-launch inventory is typically sold within the next three months. If the market prices become lower than the product inventory carrying costs, then the pre-launch inventory value is reduced to such lower market value. If the inventory produced exceeds the estimated market acceptance of the generic product and becomes short-dated, a carrying value reserve will be recorded. In all cases, the carrying value of the Company's pre-launch product inventory is lower than the respective estimated net selling prices. The carrying value of unapproved inventory less reserves was $5.3 million and $8.7 million at March 31, 2016 and December 31, 2015 , respectively. To the extent inventory is not scheduled to be utilized in the manufacturing process and/or sold within twelve months of the balance sheet date, it is included as a component of other non-current assets. Amounts classified as non-current inventory consist of raw materials, net of valuation reserves. Raw materials generally have a shelf life of approximately three to five years , while finished goods generally have a shelf life of approximately two years .

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment, net of accumulated depreciation, consists of the following (in thousands): March 31, 2016 December 31, 2015 Land $ 5,603 $ 5,773 Buildings and improvements 169,400 165,322 Equipment 136,599 135,998 Office furniture and equipment 14,975 14,548 Construction in-progress 30,238 25,659 Property, plant and equipment, gross 356,815 347,300 Less: Accumulated depreciation (137,415 ) (133,144 ) Property, plant and equipment, net $ 219,400 $ 214,156 Depreciation expense was $6.3 million and $5.4 million for the three months ended March 31, 2016 and March 31, 2015 , respectively. Unpaid vendor invoices relating to purchases of property, plant and equipment of $4.5 million and $1.3 million , which were accrued as of March 31, 2016 and March 31, 2015 , respectively, have been excluded from the purchase of property, plant, and equipment and the change in accounts payable and accrued expenses in the Company’s consolidated statements of cash flows.

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND GOODWILL	INTANGIBLE ASSETS AND GOODWILL Intangible Assets The Company’s finite-lived intangible assets, consisting of marketed product rights and royalties received from product sales from the Company’s third party partners, are amortized over the estimated useful life of the asset based on the pattern of economic benefit expected to be realized or, if that pattern is not readily determinable, on a straight-line basis. The remaining weighted-average amortization period for the Company's finite-lived intangible assets not yet fully amortized is 10.9 years as of March 31, 2016. The Company’s indefinite-lived intangible assets consist of acquired in-process research and development ("IPR&D") product rights and acquired future royalty rights to be paid based on other companies’ net sales of products not yet approved. Amortization over the estimated useful life will commence at the time of the respective product’s launch. If FDA approval to market the product is not obtained, the Company will immediately expense the related capitalized cost. The following tables show the gross carrying values and accumulated amortization, where applicable, of the Company’s intangible assets by type for the Company’s consolidated balance sheets presented (in thousands): March 31, 2016 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 544,976 $ (91,618 ) $ 453,358 Royalties 2,200 (246 ) 1,954 547,176 (91,864 ) 455,312 Non-amortized intangible assets: Acquired IPR&D product rights 62,840 — 62,840 Acquired future royalty rights 78,600 — 78,600 141,440 — 141,440 Total intangible assets $ 688,616 $ (91,864 ) $ 596,752 December 31, 2015 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 458,675 $ (82,906 ) $ 375,769 Royalties 2,200 (189 ) 2,011 460,875 (83,095 ) 377,780 Non-amortized intangible assets: Acquired IPR&D product rights 145,640 — 145,640 Acquired future royalty rights 78,600 — 78,600 224,240 — 224,240 Total intangible assets $ 685,115 $ (83,095 ) $ 602,020 During the first quarter of 2016, the Company capitalized $3.5 million of milestone payments due to an affiliate of Teva under the terms of the product agreement between the parties and related to the FDA's approval and the Company's subsequent commercial launch of EMVERM TM (mebendazole) 100 mg chewable tablets. As of December 31, 2015, the EMVERM TM acquired IPR&D product right had a carrying value of $82.8 million , which was the fair value assigned by the Company during the purchase price allocation accounting for the Tower acquisition. As a result of the Company's commercial launch of the product during the first quarter of 2016, the Company transferred the total $86.3 million of asset value from non-amortized, indefinite-lived acquired IPR&D product rights to amortized, finite-lived marketed product rights and began amortization of the asset. The EMVERM TM marketed product right intangible asset will be amortized over an estimated useful life of nine years based on the pattern of economic benefit expected to be realized through 2024. The Company recognized amortization expense of $8.8 million and $4.3 million for the three months ended March 31, 2016 and 2015 , respectively, in cost of revenues in the consolidated statements of operations presented. Assuming no changes to the gross carrying amount of finite-lived intangible assets, amortization expense for fiscal years 2016 through 2020 is estimated to be in the range of $37.8 million to $59.1 million annually. Goodwill Goodwill on the Company’s consolidated balance sheets at March 31, 2016 and December 31, 2015 is the result of the 2015 Tower acquisition and the 1999 merger of Impax Pharmaceuticals, Inc. with Global Pharmaceuticals Corporation. Goodwill had a carrying value of $208.4 million and $210.2 million at March 31, 2016 and December 31, 2015 , respectively. The change in the carrying value during the first quarter 2016 compared to December 31, 2015 was entirely attributable to the finalization of the purchase price allocation for the Tower acquisition as a result of the completion and filing of federal and state tax returns for the various entities acquired, which resulted in the adjustment of goodwill. At March 31, 2016 , the Company attributed $148.7 million and $59.7 million to the Impax Generics division and the Impax Specialty Pharma division, respectively.

ACCRUED EXPENSES

ACCRUED EXPENSES	3 Months Ended
	Mar. 31, 2016
Payables and Accruals [Abstract]
ACCRUED EXPENSES	ACCRUED EXPENSES The following table sets forth the Company’s accrued expenses (in thousands): March 31, 2016 December 31, 2015 Payroll-related expenses $ 23,500 $ 37,419 Product returns 56,044 48,950 Accrued shelf stock 9,995 6,619 Government rebates (1) 99,606 91,717 Legal and professional fees 8,965 5,929 Income taxes payable 2,558 830 Physician detailing sales force fees 327 1,132 Interest payable 3,500 500 Other 8,617 11,615 Total accrued expenses $ 213,112 $ 204,711 (1) Includes estimated $42.9 million and $40.6 million as of March 31, 2016 and December 31, 2015, respectively, of liabilities for Daraprim® chargebacks and rebates resulting from utilization by Medicaid, Medicare and other federal, state and local governmental programs, health plans and other health care providers for product sold under the Company’s labeler code, which amounts are subject to reimbursement by Turing in accordance with the terms of the Company's purchase agreement with Turing. The Company made payments of $5.1 million on Turing's behalf during the first quarter of 2016. See "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" for additional information related to the Turing receivable. Product Returns The Company maintains a return policy to allow customers to return product within specified guidelines. The Company estimates a provision for product returns as a percentage of gross sales based upon historical experience for sales made through its Impax Generics and Impax Specialty Pharma sales channels. Sales of product under the Private Label, Rx Partner and OTC Partner alliance, collaboration and supply agreements are not subject to returns. A roll-forward of the return reserve activity for the three months ended March 31, 2016 and the year ended December 31, 2015 is as follows (in thousands): Returns Reserve March 31, 2016 December 31, 2015 Beginning balance $ 48,950 $ 27,174 Acquired balances — 11,364 Provision related to sales recorded in the period 13,421 43,967 Credits issued during the period (6,327 ) (33,555 ) Ending balance $ 56,044 $ 48,950

DEBT

DEBT	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
DEBT	DEBT 2% Convertible Senior Notes due June 2022 On June 30, 2015, the Company issued an aggregate principal amount of $600.0 million of 2.00% Convertible Senior Notes due June 2022 (the “Notes”) in a private placement offering, which are the Company’s senior unsecured obligations. The Notes were issued pursuant to an Indenture dated June 30, 2015 (the “Indenture”) between the Company and Wilmington Trust, N.A. as trustee. The Indenture includes customary covenants and sets forth certain events of default after which the Notes may be due and payable immediately. The Notes will mature on June 15, 2022, unless earlier redeemed, repurchased or converted. The Notes bear interest at a rate of 2.00% per year, and interest is payable semiannually in arrears on June 15 and December 15 of each year, beginning from December 15, 2015. The conversion rate for the Notes is initially set at 15.7858 shares per $1,000 of principal amount, which is equivalent to an initial conversion price of $63.35 per share of the Company’s common stock. If a Make-Whole Fundamental Change (as defined in the Indenture) occurs or becomes effective prior to the maturity date and a holder elects to convert its Notes in connection with the Make-Whole Fundamental Change, the Company is obligated to increase the conversion rate for the Notes so surrendered by a number of additional shares of the Company’s common stock as prescribed in the Indenture. Additionally, the conversion rate is subject to adjustment in the event of an equity restructuring transaction such as a stock dividend, stock split, spinoff, rights offering, or recapitalization through a large, nonrecurring cash dividend (“standard antidilution provisions,” per FASB ASC Topic 815-40, Contracts in Entity’s Own Equity ("ASC 815-40")). The Notes are convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding December 15, 2021 only under the following circumstances: (i) If during any calendar quarter commencing after the quarter ending September 30, 2015 (and only during such calendar quarter) the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; or (ii) If during the 5 business day period after any 10 consecutive trading day period (the “measurement period”) in which the trading price per $1,000 of principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last report sale price of the Company’s common stock and the conversion rate on each such trading day; or (iii) Upon the occurrence of corporate events specified in the Indenture. On or after December 15, 2021 until the close of business on the second scheduled trading day immediately preceding the maturity date, the holders may convert their Notes at any time, regardless of the foregoing circumstances. The Company may satisfy its conversion obligation by paying or delivering, as the case may be, cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s election and in the manner and subject to the terms and conditions provided in the Indenture. Concurrently with the offering of the Notes and using a portion of the proceeds from the sale of the Notes, the Company entered into a series of convertible note hedge and warrant transactions (the “Note Hedge Transactions” and “Warrant Transactions”) which are designed to reduce the potential dilution to the Company’s stockholders and/or offset the cash payments the Company is required to make in excess of the principal amount upon conversion of the Notes. The Note Hedge Transactions and Warrant Transactions are separate transactions, in each case, entered into by the Company with a financial institution and are not part of the terms of the Notes. These transactions will not affect any holder’s rights under the Notes, and the holders of the Notes have no rights with respect to the Note Hedge Transactions and Warrant Transactions. See “Note 14. Stockholders’ Equity” for additional information. At the June 30, 2015 issuance date of the Notes, the Company did not have the necessary number of authorized but unissued shares of its common stock available to share-settle the conversion option of the Notes. Therefore, in accordance with guidance found in FASB ASC Topic 470-20, Debt with Conversion and Other Options , and FASB Topic ASC 815-15, Embedded Derivatives , the conversion option of the Notes was deemed an embedded derivative requiring bifurcation from the Notes (host contract) and separate accounting as a derivative liability. The fair value of the conversion option derivative liability at June 30, 2015 was $167.0 million , which was recorded as a reduction to the carrying value of the debt and will be accreted to interest expense over the term of the debt using the effective interest method. Although the Company received stockholder approval on December 8, 2015 to amend the Company’s Restated Certificate of Incorporation to increase the authorized number of shares of the Company’s common stock (which amendment has occurred), the debt discount remains and continues to be accreted to interest expense. See “Note 14. Stockholders’ Equity” for additional information. In connection with the issuance of the Notes, the Company incurred $18.7 million of debt issuance costs for banking, legal and accounting fees and other expenses. This amount was also recorded on the Company’s balance sheet as a reduction to the carrying value of the debt, in accordance with the Company’s early adoption of ASU No. 2015-03 - Simplifying the Presentation of Debt Issuance Costs (“ASU 2015-03”), and will be accreted to interest expense over the term of the debt using the effective interest method. For the three months ended March 31, 2016 , the Company recognized $8.3 million of interest expense related to the Notes, of which $3.0 million was cash and $5.3 million was non-cash accretion of the debt discounts recorded. As the Notes mature in 2022, they have been classified as long-term debt on the Company's consolidated balance sheets, with a carrying value of $429.9 million and $424.6 million as of March 31, 2016 and December 31, 2015 , respectively. Accrued interest payable on the Notes of $3.5 million and $0.5 million as of March 31, 2016 and December 31, 2015, respectively, is included in accrued expenses on the Company's consolidated balance sheets. Royal Bank of Canada $100.0 Million Revolver On August 4, 2015, the Company entered into a senior secured revolving credit facility (the “Revolving Credit Facility”) of up to $100 million , pursuant to a credit agreement by and among the Company, the lenders party thereto from time to time and Royal Bank of Canada, as administrative agent and collateral agent (the “Revolving Credit Facility Agreement”). The Revolving Credit Facility is available for working capital and other general corporate purposes. Borrowings under the Revolving Credit Facility will accrue interest at a rate equal to LIBOR or the base rate, plus an applicable margin. The applicable margin may be increased or reduced by 0.75% based on the Company’s total net leverage ratio. The Revolving Credit Facility will mature on August 4, 2020. No borrowings have been drawn from the Revolving Credit Facility from its inception through March 31, 2016 . Loss on Early Extinguishment of Debt – Barclays $435.0 Million Term Loan In connection with the acquisition of Tower during the first quarter of 2015, the Company entered into a $435.0 million senior secured term loan facility (the “Term Loan”) and a $50.0 million senior secured revolving credit facility (the “Barclays Revolver,” and collectively with the Term Loan, the “Barclays Senior Secured Credit Facilities”), pursuant to a credit agreement, dated as of March 9, 2015, by and among the Company, the lenders party thereto from time to time and Barclays Bank PLC ("Barclays"), as administrative and collateral agent (the “Barclays Credit Agreement”). In connection with the Barclays Senior Secured Credit Facilities, the Company incurred debt issuance costs for banking, legal and accounting fees and other expenses of $17.8 million , which were previously reflected as a discount to the carrying value of the debt on the Company’s consolidated balance sheet in accordance with ASU 2015-03. Prior to repayment of the Term Loan on June 30, 2015, this debt discount was accreted to interest expense over the term of the loan using the effective interest rate method. On June 30, 2015, the Company used $436.4 million of the proceeds from the sale of the Notes to repay the $435.0 million of principal and $1.4 million of accrued interest due on its Term Loan under the Barclays Credit Agreement. In connection with this repayment of the loan, for the quarter ended June 30, 2015, the Company recorded a loss on early extinguishment of debt of $16.9 million related to the unaccreted portion of the debt discount. For the three months ended March 31, 2015, the Company incurred total interest expense related to the Term Loan of $4.0 million , of which $3.8 million was cash and $0.2 million was non-cash accretion of the debt discount recorded. The cash interest expense includes a $2.3 million ticking fee paid to Barclays during the first quarter of 2015, prior to the funding of the Senior Secured Credit Facilities on March 9, 2015, to lock in the financing terms from the lenders' commitment of the Term Loan until the actual allocation of the loan occurred at the closing of the Tower acquisition.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Preferred Stock Pursuant to its Restated Certificate of Incorporation, as amended (the “Certificate of Incorporation”), the Company is authorized to issue 2,000,000 shares of “blank check” preferred stock, $0.01 par value per share, which enables the Board of Directors, from time to time, to create one or more new series of preferred stock. Each series of preferred stock issued can have the rights, preferences, privileges and restrictions designated by the Board of Directors. The issuance of any new series of preferred stock could affect, among other things, the dividend, voting, and liquidation rights of the Company’s common stock. The Company had no preferred stock issued or outstanding as of March 31, 2016 and December 31, 2015 . Common Stock Pursuant to its Certificate of Incorporation, the Company is authorized to issue 150,000,000 shares of common stock, $0.01 par value per share, of which 73,339,655 shares have been issued and 73,095,926 shares were outstanding as of March 31, 2016. In addition, the Company had reserved for issuance the following amounts of shares of its common stock for the purposes described below as of March 31, 2016 (in thousands): Shares issued 73,340 Stock options outstanding (1) 2,480 Conversion of Notes payable (2) 9,471 Warrants outstanding (see below) 9,471 Total shares of common stock issued and reserved for issuance 94,762 (1) See “Note 16. Share-based Compensation.” (2) See “Note 13. Debt.” Warrants As discussed in “Note 13. Debt,” on June 30, 2015, the Company entered into a series of Note Hedge Transactions and Warrant Transactions with a financial institution which are designed to reduce the potential dilution to the Company’s stockholders and/or offset the cash payments the Company is required to make in excess of the principal amount upon conversion of the Notes. Pursuant to the Warrant Transactions, the Company sold to a financial institution 9.47 million warrants to purchase the Company’s common stock, for which it received proceeds of $88.3 million . The warrants have an exercise price of $81.277 per share (subject to adjustment), are immediately exercisable, and have an expiration date of September 15, 2022. Additional Paid-in Capital Pursuant to the Note Hedge Transactions, the Company purchased from a financial institution 0.6 million call options on the Company's common stock, for which it paid consideration of $147.0 million . Each call option entitles the Company to purchase 15.7858 shares of the Company's common stock at an exercise price of $63.35 per share, is immediately exercisable, and has an expiration date of June 15, 2022, subject to earlier exercise. At the time of the Note Hedge Transactions, because of an insufficient number of authorized but unissued shares of the Company's common stock, these call options did not meet the criteria for equity classification under ASC 815-40 and were accounted for as a derivative asset. As of December 8, 2015, pursuant to the approval of the Company's stockholders to increase the number of authorized shares the Company may issue, the call options purchased pursuant to the Note Hedge Transactions (formerly a derivative asset) and the conversion option of the Notes (formerly an embedded derivative liability) were reclassified to equity in additional paid-in capital. The net effect of the reclassification of these derivatives was a $21.0 million , net of tax, increase in additional paid-in capital reflected on the Company's December 31, 2015 consolidated balance sheet.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The Company's basic earnings per common share (“EPS”) is computed by dividing net income available to the Company’s common stockholders (as presented on the consolidated statements of operations) by the weighted-average number of shares of the Company’s common stock outstanding during the period. The Company’s restricted stock awards (non-vested shares) are issued and outstanding at the time of grant but are excluded from the Company’s computation of weighted-average shares outstanding in the determination of basic EPS until vesting occurs. For purposes of calculating diluted EPS, the denominator includes both the weighted-average number of shares of common stock outstanding and the number of common stock equivalents if the inclusion of such common stock equivalents would be dilutive. Dilutive common stock equivalents potentially include warrants, stock options and non-vested restricted stock awards using the treasury stock method and the number of shares of common stock issuable upon conversion of the Company’s outstanding convertible notes payable. In the case of the Company’s outstanding convertible notes payable, the diluted EPS calculation is further affected by an add-back of interest expense, net of tax, to the numerator under the assumption that the interest would not have been incurred if the convertible notes had been converted into common stock. The following is a reconciliation of basic and diluted net loss per share of common stock for the three months ended March 31, 2016 and 2015 (in thousands, except per share amounts): Three Months Ended 2016 2015 Basic Loss Per Common Share: Net loss $ (10,408 ) $ (6,333 ) Weighted-average common shares outstanding 70,665 68,968 Basic loss per share $ (0.15 ) $ (0.09 ) Diluted Loss Per Common Share: Net loss $ (10,408 ) $ (6,333 ) Add-back of interest expense on outstanding convertible notes payable, net of tax — (1) — (2) Adjusted net loss $ (10,408 ) $ (6,333 ) Weighted-average common shares outstanding 70,665 68,968 Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance — (3) — (4) Weighted-average incremental shares assuming conversion of outstanding notes payable — (1) — (2) Diluted weighted-average common shares outstanding 70,665 (3) 68,968 (4) Diluted net loss per share $ (0.15 ) $ (0.09 ) (1) For the three month period ended March 31, 2016, the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. Accordingly, there were no numerator or denominator adjustments related to the Company’s convertible notes payable. (2) Not applicable to the period presented. (3) For the three month period ended March 31, 2016 , the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. As of March 31, 2016 , shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, include 9.47 million warrants outstanding, 9.47 million shares for conversion of outstanding convertible notes payable, 2.48 million stock options outstanding and 2.15 million non-vested restricted stock awards. (4) For the three month period ended March 31, 2015, the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. As of March 31, 2015, shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, include 3.16 million stock options outstanding and 2.48 million non-vested restricted stock awards.

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION The Company recognizes the grant date fair value of each stock option and restricted stock award over its vesting period. Stock options and restricted stock awards are granted under the Company’s Second Amended and Restated 2002 Equity Incentive Plan (the “2002 Plan”) and generally vest over a three or four year period and have a term of 10 years. Impax Laboratories, Inc. 1999 Equity Incentive Plan ("1999 Plan") The aggregate number of shares of common stock authorized for issuance pursuant to the Company’s 1999 Plan is 5,000,000 shares. There were 938 and 10,938 stock options outstanding at March 31, 2016 and December 31, 2015 , respectively, under the 1999 Plan. Impax Laboratories, Inc. Second Amended and Restated 2002 Equity Incentive Plan ("2002 Plan") The aggregate number of shares of common stock authorized for issuance pursuant to the Company's 2002 Plan is 14,950,000 shares. There were 2,479,249 and 2,394,433 stock options outstanding at March 31, 2016 and December 31, 2015 , respectively, and 2,153,083 and 2,146,498 non-vested restricted stock awards outstanding at March 31, 2016 and December 31, 2015 , respectively, under the 2002 Plan. The stock option activity for all of the Company’s equity compensation plans noted above is summarized as follows: Stock Options Number of Shares Under Option Weighted- Average Exercise Price per Share Outstanding at December 31, 2015 2,405,371 $ 21.39 Options granted 426,390 $ 13.10 Options exercised (351,574 ) $ 20.95 Options forfeited — $ — Outstanding at March 31, 2016 2,480,187 $ 23.50 Options exercisable at March 31, 2016 1,376,812 $ 16.35 As of March 31, 2016 , stock options outstanding and exercisable had average remaining contractual lives of 7.71 years and 5.58 years, respectively. Also, as of March 31, 2016 , stock options outstanding and exercisable each had aggregate intrinsic values of $26.1 million and $22.3 million , respectively, and restricted stock awards outstanding had an aggregate intrinsic value of $68.9 million . As of March 31, 2016 , the Company estimated there were 2,195,692 stock options and 1,906,109 restricted shares granted to employees which were vested or expected to vest. The Company grants restricted stock to certain eligible employees as a component of its long-term incentive compensation program. The restricted stock award grants are made in accordance with the Company’s 2002 Plan and are issued and outstanding at the time of grant but are subject to forfeiture if the vesting conditions are not met. A summary of the non-vested restricted stock awards is as follows: Restricted Stock Awards Number of Restricted Stock Awards Weighted- Average Grant Date Fair Value Non-vested at December 31, 2015 2,146,498 $ 33.20 Granted 186,264 $ 33.42 Vested (72,690 ) $ 35.67 Forfeited (106,989 ) $ 32.49 Non-vested at March 31, 2016 2,153,083 $ 33.17 Included in the 72,690 shares of restricted stock vested during the three months ended March 31, 2016 are 27,206 shares with a weighted-average fair value of $36.89 per share that were withheld for minimum withholding tax purposes upon vesting of such awards from stockholders who elected to net share settle such tax withholding obligation. As of March 31, 2016 , the Company had 1,405,039 shares available for issuance of either stock options or restricted stock awards, including 1,036,675 shares from the 2002 Plan, 296,921 shares from the 1999 Plan, and 71,443 shares from the 2001 Non-Qualified Employee Stock Purchase Plan (“ESPP”) Plan. As of March 31, 2016 , the Company had total unrecognized share-based compensation expense, net of estimated forfeitures, of $65.5 million related to all of its share-based awards, which will be recognized over a weighted average period of 2.1 years. The intrinsic value of options exercised during the three months ended March 31, 2016 and 2015 was $4.0 million and $4.2 million , respectively. The total fair value of restricted shares which vested during the three months ended March 31, 2016 and 2015 was $2.6 million and $0.6 million , respectively. The Company estimated the fair value of each stock option award on the grant date using the Black-Scholes option pricing model, wherein expected volatility is based on historical volatility of the Company’s common stock. The expected term calculation is based on the “simplified” method described in SAB No. 107, Share-Based Payment and SAB No. 110, Share-Based Payment, as the result of the simplified method provides a reasonable estimate in comparison to actual experience. The risk-free interest rate is based on the U.S. Treasury yield at the date of grant for an instrument with a maturity that is commensurate with the expected term of the stock options. The dividend yield of zero is based on the fact that the Company has never paid cash dividends on its common stock, and has no present intention to pay cash dividends. Options granted under each of the above plans generally vest from three to four years and have a term of 10 years. The amount of share-based compensation expense recognized by the Company is as follows (in thousands): Three Months Ended 2016 2015 Manufacturing expenses $ 1,368 $ 1,046 Research and development 1,340 1,365 Selling, general and administrative 4,570 4,077 Total $ 7,278 $ 6,488

RESTRUCTURINGS

RESTRUCTURINGS	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
RESTRUCTURINGS	RESTRUCTURINGS Middlesex, New Jersey Manufacturing and Packaging Operations In March 2016, the Company's Board of Directors approved a plan of restructuring designed to reduce costs, improve operating efficiencies and enhance the Company's long-term competitive position by closing the Company's Middlesex, New Jersey manufacturing and packaging site and transferring the products and the functions performed there to the Company's other facilities or to third-party manufacturers. This plan will take up to two years to complete, over which time 215 positions are currently expected to be eliminated. This plan does not impact the Company's R&D activities at the Middlesex site. Management currently estimates that over the next two years the Company will incur aggregate pre-tax charges in connection with this plan of $45.0 million to $53.0 million , of which approximately half will be incurred in 2016 and the remainder by the second quarter of 2018. The following is a summary of the total estimated charges to be incurred by major type of cost: Type of Cost Technical transfer of products Asset impairment and accelerated depreciation charges Employee retention and termination benefits Facilities lease terminations and asset retirement obligations Total estimated restructuring charges Amount Expected to be Incurred $12.0 million to $14.0 million $19.0 million to $23.0 million $12.0 million to $14.0 million $2.0 million $45.0 million to $53.0 million During the quarter ending March 31, 2016, the Company recorded an accrual for severance and retention payments of $0.7 million and recognized expenses of $0.6 million and $0.1 million for accelerated depreciation and legal and professional fees, respectively, related to the restructuring. The total charges of $1.4 million were recognized in cost of goods sold in the Company's consolidated statement of operations for the three month period ended March 31, 2016. Severance and retention payments are being accrued over the estimated service period. Hayward, California Technical Operations and R&D In November 2015, management assessed the headcount in the technical operations and research and development groups in Hayward, California, primarily as a result of the resolution of the warning letter at the Hayward facility, and determined that a reduction in force was necessary to adjust the headcount to the operating conditions of the post-warning letter resolution environment. The Company eliminated 27 positions and recorded an accrual for severance and related employee termination benefits of $2.5 million during the quarter ended December 31, 2015. As of March 31, 2016 , $1.1 million has been paid and the Company currently expects the remainder of this balance to be paid by early 2017. Philadelphia, Pennsylvania Packaging and Distribution Operations On June 30, 2015, the Company committed to a plan of restructuring of its packaging and distribution operations and as a result of this plan, the Company closed its Philadelphia packaging site and all Company-wide distribution operations were outsourced to United Parcel Services ("UPS") during the fiscal year ended December 31, 2015. The Company eliminated 93 positions and recorded an accrual for severance and related employee termination benefits of $2.6 million during the quarter ended June 30, 2015. As of March 31, 2016 , $1.6 million has been paid and the Company currently expects the remainder of this balance to be paid by the end of 2016.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company calculates its interim income tax provision in accordance with FASB ASC Topics 270 and 740. At the end of each interim period, the Company makes an estimate of the annual United States domestic and foreign jurisdictions’ expected effective tax rates and applies these rates to its respective year-to-date taxable income or loss. The computation of the annual estimated effective tax rates at each interim period requires certain estimates and assumptions including, but not limited to, the expected operating income for the year, projections of the proportion of income (or loss) earned and taxed in the United States, and the various state and local tax jurisdictions, as well as tax jurisdictions outside the United States, along with permanent differences, and the likelihood of deferred tax asset utilization. The accounting estimates used to compute the provision for income taxes may change as new events occur, more experience is acquired or additional information is obtained. The computation of the annual estimated effective tax rate includes modifications, which were projected for the year, for share-based compensation and state research and development credits, among others. In addition, the effect of changes in enacted tax laws, rates, or tax status is recognized in the interim period in which the respective change occurs. During the three month period ended March 31, 2016 and 2015, the Company recognized aggregate consolidated tax benefits of $7.1 million and $4.4 million, respectively, for U.S. domestic and foreign income taxes. The effective tax rate for the three months ended March 31, 2016 and 2015 was 41% for both periods. The amount of tax benefit recorded for the three months ended March 31, 2016 reflects the Company’s estimate as of such date of the annual effective tax rate applied to the year-to-date loss. A discrete tax benefit of $17.4 million for the reserve recorded against the Turing receivable as described above under "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" is also reflected in income tax benefit for the three months ended March 31, 2016. Excluding discrete items, the Company’s estimate of the annualized effective tax rate for the three months ended March 31, 2016 was 34% . The effective tax rate, including the effects of discrete tax income tax items, was 41% for the three months ended March 31, 2016. Due to the taxable loss for the three months ended March 31, 2016, the discrete tax benefit increased the tax rate. The increase in the aggregate tax benefit resulted from higher consolidated loss before taxes in the three month period ended March 31, 2016, as compared to the same period in the prior year. The increase in tax benefit was also a result of a change in the timing and mix of U.S. and foreign income; the exclusion of a zero-rate jurisdiction from the interim effective tax rate calculation; the inclusion of the federal research and development credit which was permanently reinstated in December of 2015; and an increase in the deferred tax asset related to a state R&D tax credit carryforward in a state with indefinite carryforwards. The Company is closely monitoring the events and circumstances that determine the need for a valuation allowance related to state research and development tax credit carryforwards and have determined that, based upon the evaluation of the provisions of ASC 740, no valuation allowance will be recorded at this time. Lineage is currently under audit for federal income tax by the U.S. Internal Revenue Service ("IRS") for the 2013 tax year, which pre-dates the Company’s acquisition of Lineage. The Company and the former stockholders of Lineage are currently cooperating with the IRS in connection with the audit. Under the terms of the Stock Purchase Agreement related to the Tower acquisition, the Company is not responsible for pre-acquisition income tax liabilities. Neither the Company nor any of its other affiliates is currently under audit for federal income tax. No provision has been made for U.S. federal deferred income taxes on accumulated earnings on foreign subsidiaries since it is the current intention of management to indefinitely reinvest the undistributed earnings in the foreign subsidiary.

ALLIANCE AND COLLABORATION AGRE

ALLIANCE AND COLLABORATION AGREEMENTS	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ALLIANCE AND COLLABORATION AGREEMENTS	ALLIANCE AND COLLABORATION AGREEMENTS The Company has entered into several alliance, collaboration, license and distribution agreements, and similar agreements with respect to certain of its products and services, with unrelated third-party pharmaceutical companies. The consolidated statements of operations include revenue recognized under agreements the Company has entered into to develop marketing and/or distribution relationships with its partners to fully leverage its technology platform and revenue recognized under development agreements which generally obligate the Company to provide research and development services over multiple periods. The Company’s alliance and collaboration agreements often include milestones and provide for milestone payments upon achievement of these milestones. Generally, the milestone events contained in the Company’s alliance and collaboration agreements coincide with the progression of the Company’s products and technologies from pre-commercialization to commercialization. The Company groups pre-commercialization milestones in its alliance and collaboration agreements into clinical and regulatory categories, each of which may include the following types of events: Clinical Milestone Events: • Designation of a development candidate . Following the designation of a development candidate, generally, IND-enabling animal studies for a new development candidate take 12 to 18 months to complete. • Initiation of a Phase I clinical trial . Generally, Phase I clinical trials take one to two years to complete. • Initiation or completion of a Phase II clinical trial . Generally, Phase II clinical trials take one to three years to complete. • Initiation or completion of a Phase III clinical trial . Generally, Phase III clinical trials take two to four years to complete. • Completion of a bioequivalence study . Generally, bioequivalence studies take three months to one year to complete. Regulatory Milestone Events: • Filing or acceptance of regulatory applications for marketing approval such as a New Drug Application in the United States or Marketing Authorization Application in Europe . Generally, it takes six to 12 months to prepare and submit regulatory filings and two months for a regulatory filing to be accepted for substantive review. • Marketing approval in a major market, such as the United States or Europe . Generally it takes one to three years after an application is submitted to obtain approval from the applicable regulatory agency. • Marketing approval in a major market, such as the United States or Europe for a new indication of an already-approved product . Generally it takes one to three years after an application for a new indication is submitted to obtain approval from the applicable regulatory agency. Commercialization Milestones Events: • First commercial sale in a particular market , such as in the United States or Europe . • Product sales in excess of a pre-specified threshold, such as annual sales exceeding $100 million . The amount of time to achieve this type of milestone depends on several factors including but not limited to the dollar amount of the threshold, the pricing of the product and the pace at which customers begin using the product. License and Distribution Agreement with Shire In January 2006, the Company entered into a License and Distribution Agreement with an affiliate of Shire Laboratories, Inc., which was subsequently amended (“Prior Shire Agreement”), under which the Company received a non-exclusive license to market and sell an authorized generic of Shire’s Adderall XR® product (“AG Product”) subject to certain conditions, but in any event by no later than January 1, 2010. The Company commenced sales of the AG Product in October 2009. On February 7, 2013, the Company entered into an Amended and Restated License and Distribution Agreement with Shire (the “Amended and Restated Shire Agreement”), which amended and restated the Prior Shire Agreement. The Amended and Restated Shire Agreement was entered into by the parties in connection with the settlement of the Company’s litigation with Shire relating to Shire’s supply of the AG Product to the Company under the Prior Shire Agreement. During 2013, the Company received a payment of $48.0 million from Shire in connection with such litigation settlement, which was recorded in the first quarter of 2013 under the line item “Other Income” on the consolidated statement of operations. Under the Amended and Restated Shire Agreement, Shire was required to supply the AG Product and the Company was responsible for marketing and selling the AG Product subject to the terms and conditions thereof until the earlier of (i) the first commercial sale of the Company’s generic equivalent product to Adderall XR® and (ii) September 30, 2014 (the “Supply Term”), subject to certain continuing obligations of the parties upon expiration or early termination of the Supply Term, including Shire’s obligation to deliver AG Products still owed to the Company as of the end of the Supply Term. The Company is required to pay a profit share to Shire on sales of the AG Product, of which the Company owed a profit share payable to Shire of $4.0 million and $5.8 million on sales of the AG Product during the three months ended March 31, 2016 and 2015 , respectively, with a corresponding charge included in the cost of revenues line in the consolidated statement of operations. Although the Supply Term expired on September 30, 2014, the Company was permitted to sell any AG Products in its inventory or owed to the Company by Shire under the Amended and Restated Shire Agreement until all such products are sold. The Company continued to pay a profit share to Shire on sales of such products during the three months ended March 31, 2016 . Development, Supply and Distribution Agreement with TOLMAR, Inc. In June 2012, the Company entered into the Tolmar Agreement with Tolmar. Under the terms of the Tolmar Agreement, Tolmar granted to the Company an exclusive license to commercialize up to 11 generic topical prescription drug products, including ten currently approved products and one product pending approval at the FDA, in the United States and its territories. Under the terms of the Tolmar Agreement, Tolmar is responsible for developing and manufacturing the products, and the Company is responsible for marketing and sale of the products. The Company is required to pay a profit share to Tolmar on sales of each product commercialized pursuant to the terms of the Tolmar Agreement. The Company paid Tolmar a $21.0 million upfront payment upon signing of the agreement and, pursuant to the terms of the agreement, is also required to make payments to Tolmar upon the achievement of certain specified milestone events. Such contingent milestone payments will initially be recognized in the period the triggering event occurs. Milestone payments which are contingent upon commercialization events will be accounted for as an additional cost of acquiring the product license rights. Milestone payments which are contingent upon regulatory approval events will be capitalized and amortized over the remaining estimated useful life of the approved product. During the year ended December 31, 2012, the Company made a $1.0 million milestone payment and, during the fourth quarter of 2013, the Company made a $12.0 million payment to Tolmar upon Tolmar’s achievement of a regulatory milestone event in accordance with the terms of pursuant to the Tolmar Agreement. The $21.0 million upfront payment for the Tolmar product rights has been allocated to the underlying topical products based upon the relative fair value of each product and will be amortized over the remaining estimated useful life of each underlying product, ranging from five to 12 years, starting upon commencement of commercialization activities by the Company during the second half of 2012. The amortization of the Tolmar product rights has been included as a component of cost of revenues on the consolidated statements of operations. The Company initially allocated $1.55 million of the upfront payment to two products which were in development and has recorded such amount as in-process research and development expense in its results of operations for the year ended December 31, 2012. The Company similarly recorded the $1.0 million milestone paid in the year ended December 31, 2012 as a research and development expense. The Company is required to pay a profit share to Tolmar on sales of the topical products, of which the Company owed a profit share payable to Tolmar of $24.7 million and $7.5 million during the three months ended March 31, 2016 and 2015 , respectively, with a corresponding charge included in the cost of revenues line in the Company’s consolidated statement of operations. During the fourth quarter of 2014, the Company paid a $2.0 million milestone related to the Diclofenac Sodium Gel 3% or Solaraze® product to Tolmar pursuant to the Tolmar Agreement. During the second quarter of 2015, the Company paid a $5.0 million milestone related to certain topical products pursuant to the Tolmar Agreement. The Company entered into a Loan and Security Agreement with Tolmar in March 2012 (the “Tolmar Loan Agreement”), under which the Company agreed to lend to Tolmar one or more loans through December 31, 2014, in an aggregate amount not to exceed $15.0 million. As of March 31, 2016 and December 31, 2015, Tolmar owed the Company $15.0 million under the Tolmar Loan Agreement, which is included in “Other Assets” on the consolidated balance sheets. The outstanding principal amount of, including any accrued and unpaid interest on, the loans under the Tolmar Loan Agreement are payable by Tolmar beginning from March 31, 2017 through March 31, 2020 or the maturity date, in accordance with the terms therein. Tolmar may prepay all or any portion of the outstanding balance of the loans prior to the maturity date without penalty or premium. Strategic Alliance Agreement with Teva The Company entered into a Strategic Alliance Agreement with Teva Pharmaceuticals Curacao N.V., a subsidiary of Teva Pharmaceutical Industries Limited, in June 2001, which was subsequently amended (“Teva Agreement”). The Teva Agreement commits the Company to develop and manufacture, and Teva to distribute, a specified number of controlled release generic pharmaceutical products (“generic products”), each for a 10 -year period. The Company is required to develop the products, obtain FDA approval to market the products, and manufacture the products for Teva. The revenue the Company earns from the sale of product under the Teva Agreement consists of Teva’s reimbursement of the Company’s manufacturing costs plus a profit share on Teva’s sales of the product to its customers. The Company invoices Teva for the manufacturing costs or products it ships to Teva and payment is due within 30 days. Teva has the right to determine all terms and conditions of the product sales to its customers. Within 30 days of the end of each calendar quarter, Teva is required to provide the Company with a report of its net sales and profits during the quarter and to pay the Company its share of the profits resulting from those sales. Net sales are Teva’s gross sales less discounts, rebates, chargebacks, returns, and other adjustments, all of which are based upon fixed percentages, except chargebacks, which are estimated by Teva and subject to a true-up reconciliation. As of March 31, 2016 , the Company was supplying Teva with oxybutynin extended release tablets (Ditropan XL® 5 mg, 10 mg and 15 mg extended release tablets) and has agreed to supply another product (currently under development) to Teva; the other products under the Teva Agreement have either been returned to the Company, are being manufactured by Teva at its election, were voluntarily withdrawn from the market or the Company’s obligations to supply such product had expired or were terminated in accordance with the agreement. OTC Partners Alliance Agreement In June 2002, the Company entered into a Development, License and Supply Agreement with Pfizer, Inc., formerly Wyeth LLC (“Pfizer”), for a term of 15 years, relating to the Company’s Loratadine and Pseudoephedrine Sulfate 5 mg/120 mg 12-hour Extended Release Tablets and Loratadine and Pseudoephedrine Sulfate 10 mg/240 mg 24-hour Extended Release Tablets for the OTC market. The Company previously developed the products, and is currently only responsible for manufacturing the products, and Pfizer is responsible for marketing and sale. The agreement included payments to the Company upon achievement of development milestones, as well as royalties paid to the Company by Pfizer on its sales of the product. Pfizer launched this product in May 2003 as Alavert® D-12 Hour. In February 2005, the agreement was partially cancelled with respect to the 24-hour Extended Release Product due to lower than planned sales volume. In December 2011, Pfizer and the Company entered into an agreement with L. Perrigo Company (“Perrigo”), which was subsequently amended whereby the parties agreed that the Company would supply the Company’s Loratadine and Pseudoephedrine Sulfate 5 mg/120 mg 12-hour Extended Release Tablets to Perrigo in the United States and its territories. The agreements with Pfizer and Perrigo are no longer a core area of the Company’s business, and the over-the-counter pharmaceutical products the Company sells to Pfizer and Perrigo under the agreements are older products which are only sold to Pfizer and to Perrigo. As noted above, the Company is currently only required to manufacture the products under its agreements with Pfizer and Perrigo. The Company recognizes profit share revenue in the period earned. Agreements with Valeant Pharmaceuticals International, Inc. In November 2008, the Company and Valeant Pharmaceuticals International, Inc., formerly Medicis Pharmaceutical Corporation (“Valeant”), entered into a Joint Development Agreement and a License and Settlement Agreement (the “Joint Development Agreement”). The Joint Development Agreement provides for the Company and Valeant to collaborate in the development of a total of five dermatology products, including four of the Company’s generic products and one branded advanced form of Valeant’s SOLODYN ® product. Under the provisions of the Joint Development Agreement the Company received a $40.0 million upfront payment, paid by Valeant in December 2008. The Company has also received an aggregate of $15.0 million in milestone payments composed of two $5 million milestone payments, paid by Valeant in March 2009 and September 2009, a $2.0 million milestone payment paid by Valeant in December 2009, and a $3.0 million milestone payment paid by Valeant in March 2011. The Company has the potential to receive up to an additional $8.0 million of contingent regulatory milestone payments each of which the Company believes to be substantive, as well as the potential to receive royalty payments from sales, if any, by Valeant of its advanced form SOLODYN ® brand product. Finally, to the extent the Company commercializes any of its four generic dermatology products covered by the Joint Development Agreement, the Company will pay to Valeant a gross profit share on sales of such products. The Company began selling one of the four dermatology products during the year ended December 31, 2011. As of December 31, 2014, the full amount of deferred revenue under the Joint Development Agreement was recognized. The Joint Development Agreement results in three items of revenue for the Company, as follows: (1) Research & Development Services. Revenue received from the provision of research and development services including the $40.0 million upfront payment and the $12.0 million of milestone payments received prior to January 1, 2011, have been deferred and are being recognized on a straight-line basis over the expected period of performance of the research and development services. During the three month period ended March 31, 2013, the Company extended the revenue recognition period for the Joint Development Agreement from the previous recognition period ending in November 2013 to December 2014, due to changes in the estimated timing of completion of certain research and development activities. This change was made on a prospective basis, and resulted in a reduced periodic amount of revenue recognized in current and future periods. Revenue from the remaining $8.0 million of contingent milestone payments, including the $3.0 million received from Valeant in March 2011, will be recognized using the Milestone Method of accounting. Revenue recognized under the Joint Development Agreement is included in “Note 23. Supplementary Financial Information,” in the line item captioned “Other Revenues.” (2) Royalty Fees Earned - Valeant’s Sale of Advanced Form SOLODYN® (Brand) Product. Under the Joint Development Agreement, the Company granted Valeant a license for the advanced form of the SOLODYN® product, with the Company receiving royalty fee income under such license for a period ending eight years after the first commercial sale of the advanced form SOLODYN® product. Commercial sales of the new SOLODYN® product, if any, are expected to commence upon FDA approval of Valeant’s NDA. The royalty fee income, if any, from the new SOLODYN® product, will be recognized by the Company as current period revenue when earned. (3) Accounting for Sales of the Company’s Four Generic Dermatology Products. Upon FDA approval of the Company’s ANDA for each of the four generic products covered by the Joint Development Agreement, the Company will have the right (but not the obligation) to begin manufacture and sale of its four generic dermatology products. The Company sells its manufactured generic products to all Impax Generics division customers in the ordinary course of business through its Impax Generics Product sales channel. The Company accounts for the sale, if any, of the generic products covered by the Joint Development Agreement as current period revenue according to the Company’s revenue recognition policy applicable to its Impax Generics products. To the extent the Company sells any of the four generic dermatology products covered by the Joint Development Agreement, the Company pays Valeant a gross profit share, with such profit share payments accounted for as a current period cost of revenues in the consolidated statement of operations. Development and Co-Promotion Agreement with Endo Pharmaceuticals Inc. In June 2010, the Company and Endo Pharmaceuticals, Inc. ("Endo") entered into a Development and Co-Promotion Agreement (“Endo Agreement”) under which the Company and Endo agreed to collaborate in the development and commercialization of a next-generation advanced form of the Company’s lead branded product candidate ("Endo Agreement Product"). The Endo Agreement was terminated upon mutual agreement by the parties effective December 23, 2015. Under the provisions of the Endo Agreement, in June 2010, Endo paid to the Company a $10.0 million upfront payment. Prior to termination of the agreement, the Company also had the potential to receive up to an additional $30.0 million of contingent milestone payments. Prior to the termination of the Endo Agreement, the Company had recognized the $10.0 million upfront payment as revenue on a straight-line basis over a period of 112 months , which was the estimated expected period of performance of research and development activities under the Endo Agreement, commencing with the June 2010 effective date of the Endo Agreement and ending in September 2019, the estimated date of FDA approval of the Company's NDA for the Endo Agreement Product. The FDA approval of the Endo Agreement Product NDA represented the end of the Company’s expected period of performance, as the Company would have had no further contractual obligation to perform research and development activities under the Endo Agreement, and therefore the earnings process would have been completed on such date. There was no deferred revenue under the Endo Agreement as of March 31, 2016 and December 31, 2015. Revenue recognized under the Endo Agreement was reported in “Note 23. Supplementary Financial Information” in the line item captioned “Other Revenues”. The Company and Endo also entered into a Settlement and License Agreement in June 2010 (the “Endo Settlement Agreement”) pursuant to which Endo agreed to make a payment to the Company should prescription sales of Opana ® ER (as defined in the Endo Settlement Agreement) fall below a predetermined contractual threshold in the quarter immediately prior to the Company launching a generic version of Opana ® ER. As a result of the Company’s launch of its generic version of Opana ER in January 2013 and Endo’s prescription sales of Opana ER during the fourth quarter of 2012, the Company recorded a $102.0 million settlement gain during the three month period ended March 31, 2013. Payment of the $102.0 million settlement was received from Endo in April 2013. Distribution, License, Development and Supply Agreement with AstraZeneca UK Limited In January 2012, the Company entered into the AZ Agreement with AstraZeneca. Under the terms of the AZ Agreement, AstraZeneca granted to the Company an exclusive license to commercialize the tablet, orally disintegrating tablet and nasal spray formulations of Zomig® (zolmitriptan) products for the treatment of migraine headaches in the United States and in certain U.S. territories, except during an initial transition period when AstraZeneca fulfilled all orders of Zomig® products on the Company’s behalf and AstraZeneca paid to the Company the gross profit on such Zomig® products. The Company is obligated to fulfill certain minimum requirements with respect to the promotion of currently approved Zomig® products as well as other dosage strengths of such products approved by the FDA in the future. The Company may, but has no obligation to, develop and commercialize additional products containing zolmitriptan and additional indications for Zomig®, subject to certain restrictions as set forth in the AZ Agreement. The Company will be responsible for conducting clinical studies and preparing regulatory filings related to the development of any such additional products and would bear all related costs. During the term of the AZ Agreement, AstraZeneca will continue to be the holder of the NDA for existing Zomig® products, as well as any future dosage strengths thereof approved by the FDA, and will be responsible for certain regulatory and quality-related activities for such Zomig® products. AstraZeneca will manufacture and supply Zomig® products to the Company and the Company will purchase its requirements of Zomig® products from AstraZeneca until a date determined in the AZ Agreement. Thereafter, AstraZeneca may terminate its supply obligations upon certain advance notice to the Company, in which case the Company would have the right to manufacture or have manufactured its own requirements for the applicable Zomig® product. Under the terms of the AZ Agreement, AstraZeneca was required to make payments to the Company representing 100% of the gross profit on sales of AstraZeneca-labeled Zomig® products during the specified transition period. The Company received transition payments from AstraZeneca aggregating $43,564,000 during 2012. Beginning in January 2013, the Company was obligated to pay AstraZeneca tiered royalties on net sales of branded Zomig® products, depending on brand exclusivity and subject to customary reductions and other terms and conditions set forth in the AZ Agreement. The Company is also obligated to pay AstraZeneca royalties after a certain specified date based on gross profit from sales of authorized generic versions of the Zomig® products subject to certain terms and conditions set forth in the AZ Agreement. In May 2013, the Company’s exclusivity period for branded Zomig® tablets and orally disintegrating tablets expired and the Company launched authorized generic versions of those products in the United States. The Company owed a royalty payable to AstraZeneca of $4,019,000 and $4,025,000 during the three months ended March 31, 2016 and 2015 , respectively, with a corresponding charge included in the cost of revenues line on the consolidated statements of operations. Agreement with DURECT Corporation During the three month period ended March 31, 2014, the Company entered into an agreement with DURECT Corporation (“Durect”) granting the Company the exclusive worldwide rights to develop and commercialize DURECT’s investigational transdermal bupivacaine patch for the treatment of pain associated with post-herpetic neuralgia (PHN), referred to by the Company as IPX239. The Company paid Durect a $2 million up-front payment upon signing of the agreement which was recognized immediately as research and development expense. The Company has the potential to pay up to $61 million in additional contingent milestone payments upon the achievement of predefined development and commercialization milestones. If IPX239 is commercialized, Durect would also receive a tiered royalty on product sales. Product Acquisition Agreement with Teva Pharmaceuticals USA, Inc. In August 2013, the Company, through its Amedra Pharmaceuticals subsidiary, entered into a product acquisition agreement (the “Teva Product Acquisition Agreement”) with Teva Pharmaceuticals USA, Inc. (“Teva”) pursuant to which the Company acquired the assets (including the ANDA and other regulatory materials) and related liabilities related to Teva’s mebendazole tablet product in all dosage forms. During the first quarter of 2016, the Company recognized $3.5 million of milestone payments due to Teva under the terms of the agreement related to the FDA's approval and the Company's subsequent launch of EMVERM™ (mebendazole) 100 mg chewable tablets. The Company is also obligated to pay Teva a royalty payment based on net sales of EMVERM™, including a specified annual minimum royalty payment, subject to customary reductions and the other terms and conditions set forth in the Teva Product Acquisition Agreement.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Executive Employment Agreements The Company is a party to employment and separation agreements with certain members of its executive management team that provide for severance and other payments following termination of their employment for various reasons. Lease Agreements The Company leases land, office space, manufacturing, warehouse and research and development facilities, and equipment under non-cancelable operating leases expiring at various dates through December 2026. Purchase Order Commitments As of March 31, 2016 , the Company had $66.1 million of open purchase order commitments, primarily for raw materials. The terms of these purchase order commitments are generally less than one year in duration. Taiwan Facility Expansion The Company has entered into several contracts related to ongoing expansion activities at its Taiwan manufacturing facility. As of March 31, 2016 , the Company had remaining obligations under these contracts of $1.8 million .

LEGAL AND REGULATORY MATTERS

LEGAL AND REGULATORY MATTERS	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
LEGAL AND REGULATORY MATTERS	LEGAL AND REGULATORY MATTERS Patent Litigation There is substantial litigation in the pharmaceutical, biological, and biotechnology industries with respect to the manufacture, use, and sale of new products which are the subject of conflicting patent and intellectual property claims. One or more patents often cover the brand name products for which the Company is developing generic versions and the Company typically has patent rights covering the Company’s branded products. Under federal law, when a drug developer files an ANDA for a generic drug seeking approval before expiration of a patent, which has been listed with the FDA as covering the brand name product, the developer must certify its product will not infringe the listed patent(s) and/or the listed patent is invalid or unenforceable (commonly referred to as a “Paragraph IV” certification). Notices of such certification must be provided to the patent holder, who may file a suit for patent infringement within 45 days of the patent holder’s receipt of such notice. If the patent holder files suit within the 45 days period, the FDA can review and approve the ANDA, but is prevented from granting final marketing approval of the product until a final judgment in the action has been rendered in favor of the generic drug developer, or 30 months from the date the notice was received, whichever is sooner. The Company’s generic products division is typically subject to patent infringement litigation brought by branded pharmaceutical manufacturers in connection with the Company’s Paragraph IV certifications seeking an order delaying the approval of the Company’s ANDA until expiration of the patent(s) at issue in the litigation. Likewise, the Company’s branded products division is currently involved in patent infringement litigation against generic drug manufacturers who have filed Paragraph IV certifications to market their generic drugs prior to expiration of the Company’s patents at issue in the litigation. The uncertainties inherent in patent litigation make the outcome of such litigation difficult to predict. For the Company’s generic products division, the potential consequences in the event of an unfavorable outcome in such litigation include delaying launch of its generic products until patent expiration. If the Company were to launch its generic product prior to successful resolution of a patent litigation, the Company could be liable for potential damages measured by the profits lost by the branded product manufacturer rather than the profits earned by the Company if we are found to infringe a valid, enforceable patent. For the Company’s branded products division, an unfavorable outcome may significantly accelerate generic competition ahead of expiration of the patents covering the Company’s branded products. All such litigation typically involves significant expense. The Company is generally responsible for all of the patent litigation fees and costs associated with current and future products not covered by its alliance and collaboration agreements. The Company has agreed to share legal expenses with respect to third-party and Company products under the terms of certain of the alliance and collaboration agreements. The Company records the costs of patent litigation as expense in the period when incurred for products it has developed, as well as for products which are the subject of an alliance or collaboration agreement with a third-party. Although the outcome and costs of the asserted and unasserted claims is difficult to predict, based on the information presently known to management, the Company does not currently expect the ultimate liability, if any, for such matters to have a material adverse effect on its business, financial condition, results of operations, or cash flows. Patent Infringement Litigation Endo Pharmaceuticals Inc. and Grunenthal GmbH v. Impax Laboratories, Inc. and ThoRx Laboratories, Inc. (Oxymorphone hydrochloride); Endo Pharmaceuticals Inc. and Grunenthal GmbH v. Impax Laboratories, Inc. (Oxymorphone hydrochloride) In November 2012, Endo Pharmaceuticals, Inc. and Grunenthal GmbH (collectively, “Endo”) filed suit against ThoRx Laboratories, Inc., a wholly owned subsidiary of the Company (“ThoRx”), and the Company in the U.S. District Court for the Southern District of New York alleging patent infringement based on the filing of ThoRx’s ANDA relating to Oxymorphone hydrochloride, Extended Release tablets, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30 mg and 40 mg, generic to Opana ER®. In January 2013, Endo filed a separate suit against the Company in the U.S. District Court for the Southern District of New York alleging patent infringement based on the filing of the Company’s ANDA relating to the same products. ThoRx and the Company filed an answer and counterclaims to the November 2012 suit and the Company filed an answer and counterclaims with respect to the January 2013 suit. A bench trial was completed in April 2015. In August 2015, the Court entered judgment that the products described in the Company’s and ThoRx’s ANDAs would, if marketed, infringe certain claims of the patents asserted by Endo and Grunenthal. The Court also found that the asserted claims of patents owned by Endo were not invalid, but that the asserted claims of patents owned by Grunenthal were invalid. As a result, the Court enjoined the Company and ThoRx from marketing their products until expiration of the Endo patents in 2023. Endo filed post-trial motions to correct and amend the judgment, which were decided on April 29, 2016. T he Court has requested further post-trial briefing. All parties have filed notices of appeal with respect to the Court's judgment. The appeals are deactivated until resolution of the post-trial proceedings. In November 2014, Endo Pharmaceuticals Inc. and Mallinckrodt LLC filed suit against the Company in the U.S. District Court for the District of Delaware making additional allegations of patent infringement based on the filing of the Company’s Oxymorphone hydrochloride ANDA described above. Also in November 2014, Endo and Mallinckrodt filed a separate suit in the U.S. District Court for the District of Delaware making additional allegations of patent infringement based on the filing of the ThoRx Oxymorphone hydrochloride ANDA described above. ThoRx and the Company filed an answer and counterclaim to those suits in which they are named as a defendant. The cases are currently stayed pending the outcome of further proceedings in related cases in these District of Delaware cases and/or an appellate decision in the New York proceedings described above. In May 2016, Endo Pharmaceuticals Inc. filed suit against the Company in the U.S. District Court for the District of New Jersey, alleging that the Company’s marketed oxymorphone hydrochloride tablets infringe certain patents owned by Endo. Endo’s complaint also alleges that the Company and Endo entered into a settlement and license agreement with respect to these products, but that the Company later breached that contract and breached its implied duty of good faith and fair dealing with respect to that agreement. The Company has not yet responded to the complaint. Impax Laboratories Inc., et al. v. Lannett Holdings, Inc. and Lannett Company (Zomig®) In July 2014, the Company filed suit against Lannett Holdings, Inc. and Lannett Company (collectively, “Lannett”) in the United States District Court for the District of Delaware, alleging patent infringement based on the filing of the Lannett ANDA relating to Zolmitriptan Nasal Spray, 5mg, generic to Zomig® Nasal Spray. Lannett filed an answer and counterclaims alleging non-infringement and invalidity in September 2014, and the Company filed an answer to the counterclaims in October 2014. Discovery is proceeding, and trial is set for September 6, 2016. On July 28, 2015, Lannett filed petitions for Inter Partes Review (“IPR”) of U.S. Patent Nos. 6,750,237 and 7,220,767 related to the product in the U.S. Patent and Trademark Office before the Patent Trial and Appeal Board (“PTAB”). Patent owner filed its preliminary responses in these PTAB proceedings on November 4, 2015. In January and February 2016, the PTAB denied Lannett’s petitions, declining to institute IPR proceedings with respect to the patents. Impax Laboratories Inc., et al. v. Actavis Laboratories, Inc. and Actavis Pharma Inc. ( Rytary ® ) In September 2015, the Company filed suit against Actavis Laboratories, Inc. and Actavis Pharma Inc. (collectively, “Actavis”) in the United States District Court for the District of New Jersey, alleging patent infringement based on the filing of the Actavis ANDA relating to carbidopa and levodopa extended release capsules, generic to Rytary ® . Actavis filed an answer and counterclaims on November 19, 2015. Discovery is proceeding. A claim construction hearing is set for November/December 2016 and trial is scheduled for September 2017. Shire LLC v. CorePharma LLC (Mixed Amphetamines) In September 2014, Shire LLC (“Shire”) filed suit against CorePharma LLC, a wholly-owned subsidiary of the Company, in the United States District Court for the District of New Jersey alleging patent infringement based on the filing of CorePharma’s ANDA relating to dextroamphetamine sulfate, dextroamphetamine saccharate, amphetamine aspartate monohydrate, amphetamine sulfate extended-release capsules, 5 mg, 10 mg, 15 mg, 20 mg, 25 mg and 30 mg, generic to Adderall XR®. On November 14, 2014, CorePharma filed an answer and counterclaims. The case was settled and the Court dismissed the case on February 2, 2016. Other Litigation Related to the Company’s Business Solodyn ® Antitrust Class Actions From July 2013 to January 2016, 18 complaints were filed as class actions on behalf of direct and indirect purchasers, as well as by certain direct purchasers against manufacturers of the brand drug Solodyn® and its generic equivalents, including the Company. On July 22, 2013, Plaintiff United Food and Commercial Workers Local 1776 & Participating Employers Health and Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On July 23, 2013, Plaintiff Rochester Drug Co-Operative, Inc., a direct purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 1, 2013, Plaintiff International Union of Operating Engineers Local 132 Health and Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Northern District of California on behalf of itself and others similarly situated. On August 29, 2013, this Plaintiff withdrew its complaint from the United States District Court for the Northern District of California, and on August 30, 2013, re-filed the same complaint in the United States Court for the Eastern District of Pennsylvania, on behalf of itself and others similarly situated. On August 9, 2013, Plaintiff Local 274 Health & Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 12, 2013, Plaintiff Sheet Metal Workers Local No. 25 Health & Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 27, 2013, Plaintiff Fraternal Order of Police, Fort Lauderdale Lodge 31, Insurance Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 29, 2013, Plaintiff Heather Morgan, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 30, 2013, Plaintiff Plumbers & Pipefitters Local 178 Health & Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On September 9, 2013, Plaintiff Ahold USA, Inc., a direct purchaser, filed a class action complaint in the United States District Court for the District of Massachusetts on behalf of itself and others similarly situated. On September 24, 2013, Plaintiff City of Providence, Rhode Island, an indirect purchaser, filed a class action complaint in the United States District Court for the District of Arizona on behalf of itself and others similarly situated. On October 2, 2013, Plaintiff International Union of Operating Engineers Stationary Engineers Local 39 Health & Welfare Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the District of Massachusetts on behalf of itself and others similarly situated. On October 7, 2013, Painters District Council No. 30 Health and Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the District of Massachusetts on behalf of itself and others similarly situated. On October 25, 2013, Plaintiff Man-U Service Contract Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On March 13, 2014, Plaintiff Allied Services Division Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the District of Massachusetts on behalf of itself and others similarly situated. On March 19, 2014, Plaintiff NECA-IBEW Welfare Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the District of Massachusetts on behalf of itself and others similarly situated. On February 25, 2014, the United States Judicial Panel on Multidistrict Litigation ordered the pending actions transferred to the District of Massachusetts for coordinated pretrial proceedings, as In Re Solodyn (Minocycline Hydrochloride) Antitrust Litigation. On March 26, 2015, Walgreen Co., The Kruger Co., Safeway Inc., HEB Grocery Company L.P., Albertson’s LLC, direct purchasers, filed a separate complaint in the United States District Court for the Middle District of Pennsylvania. On April 8, 2015, the Judicial Panel on Multi-District Litigation ordered the action be transferred to the District of Massachusetts, to be coordinated or consolidated with the coordinated proceedings. The original complaint filed by the plaintiffs asserted claims only against defendant Medicis. On October 5, 2015, the plaintiffs filed an amended complaint asserting claims against the Company and the other generic defendants. On April 16, 2015, Rite Aid Corporation and Rite Aid Hdqtrs. Corp, direct purchasers, filed a separate complaint in the United States District Court for the Middle District of Pennsylvania. On May 1, 2015, the Judicial Panel on Multi-District Litigation ordered the action be transferred to the District of Massachusetts, to be coordinated or consolidated with the coordinated proceedings. The original complaint filed by the plaintiffs asserted claims only against defendant Medicis. On October 5, 2015, the plaintiffs filed an amended complaint asserting claims against the Company and the other generic defendants. On January 25, 2016, CVS Pharmacy, Inc., a direct purchaser, filed a separate complaint in the United States District Court for the Middle District of Pennsylvania. On February 11, 2016, the Judicial Panel on Multi-District Litigation ordered the action to be transferred to the District of Massachusetts to be coordinated or consolidated with the coordinated proceedings. The consolidated amended complaints allege that Medicis engaged in anticompetitive schemes by, among other things, filing frivolous patent litigation lawsuits, submitting frivolous Citizen Petitions, and entering into anticompetitive settlement agreements with several generic manufacturers, including the Company, to delay generic competition of Solodyn® and in violation of state and federal antitrust laws. Plaintiffs seek, among other things, unspecified monetary damages and equitable relief, including disgorgement and restitution. On August 14, 2015, the Court granted in part and denied in part defendants’ motion to dismiss the consolidated amended complaints. Discovery is ongoing. No trial date has been scheduled. Opana ER® FTC Antitrust Suit As previously disclosed, on February 25, 2014, the Company received a Civil Investigative Demand ("CID") from the FTC concerning its investigation into the drug Opana® ER and its generic equivalents. According to the FTC, the investigation relates to whether Endo Pharmaceuticals, Inc. (“Endo”) and the Company have engaged or are engaged in unfair methods of competition in or affecting commerce by (i) entering into agreements regarding Opana® ER or its generic equivalents and/or (ii) engaging in other conduct regarding the regulatory filings, sale or marketing of Opana® ER or its generic equivalents. On March 30, 2016, the FTC filed a complaint against the Company, Endo, and others in the United States District Court for the Eastern District of Pennsylvania, alleging that the Company and Endo violated antitrust laws when they entered into a June 2010 co-promotion and development agreement and a June 2010 settlement agreement that resolved patent litigation in connection with the submission of the Company’s ANDA for generic original Opana® ER. Opana ER® Antitrust Class Actions From June 2014 to February 2016, 14 complaints were filed as class actions on behalf of direct and end-payor (indirect) purchasers, as well as by certain direct purchasers, against the manufacturer of the brand drug Opana ER® and the Company. On June 4, 2014, Plaintiff Fraternal Order of Police, Miami Lodge 20, Insurance Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On June 4, 2014, Plaintiff Rochester Drug Co-Operative, Inc., a direct purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On June 6, 2014, Plaintiff Value Drug Company, a direct purchaser, filed a class action complaint in the United States District Court for the Northern District of California on behalf of itself and others similarly situated. On June 26, 2014, this Plaintiff withdrew its complaint from the United States District Court for the Northern District of California, and on July 16, 2014, re-filed the same complaint in the United States District Court for the Northern District of Illinois, on behalf of itself and others similarly situated. On June 19, 2014, Plaintiff Wisconsin Masons’ Health Care Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Northern District of Illinois on behalf of itself and others similarly situated. On July 17, 2014, Plaintiff Massachusetts Bricklayers, an indirect purchaser, filed a class action complaint in the United States District Court for the Eastern District of Pennsylvania on behalf of itself and others similarly situated. On August 11, 2014, Plaintiff Pennsylvania Employees Benefit Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Northern District of Illinois on behalf of itself and others similarly situated. On September 19, 2014, Plaintiff Meijer Inc., a direct purchaser, filed a class action complaint in the United States District Court for the Northern District of Illinois on behalf of itself and others similarly situated. On October 3, 2014, Plaintiff International Union of Operating Engineers, Local 138 Welfare Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Northern District of Illinois on behalf of itself and others similarly situated. On November 17, 2014, Louisiana Health Service & Indemnity Company d/b/a Blue Cross and Blue Shield of Louisiana, an indirect purchaser, filed a class action complaint in the United Stated District Court for the Middle District of Louisiana on behalf of itself and others similarly situated. On December 19, 2014, Plaintiff Kim Mahaffay, an indirect purchaser, filed a class action complaint in the Superior Court of the State of California, Alameda County, on behalf of herself and others similarly situated. On January 27, 2015, the Defendants removed the action to the United States District Court for the Northern District of California. On January 12, 2015, Plaintiff Plumbers & Pipefitters Local 178 Health & Welfare Trust Fund, an indirect purchaser, filed a class action complaint in the United States District Court for the Northern District of Illinois on behalf of itself and others similarly situated. On December 12, 2014, the United States Judicial Panel on Multidistrict Litigation ordered the pending actions transferred to the Northern District of Illinois for coordinated pretrial proceedings, as In Re Opana ER Antitrust Litigation. On March 26, 2015 Walgreen Co., The Kruger Co., Safeway Inc., HEB Grocery Company L.P., Albertson’s LLC, direct purchasers, filed a separate complaint in the United States District Court for the Northern District of Illinois. On April 23, 2015, Rite Aid Corporation and Rite Aid Hdqtrs. Corp, direct purchasers, filed a separate complaint in the United States District Court for the Northern District of Illinois. In each case, the complaints allege that Endo engaged in an anticompetitive scheme by, among other things, entering into an anticompetitive settlement agreement with the Company to delay generic competition of Opana ER® and in violation of state and federal antitrust laws. Plaintiffs seek, among other things, unspecified monetary damages and equitable relief, including disgorgement and restitution. Consolidated amended complaints were filed on May 4, 2015 by direct purchaser plaintiffs and end-payor (indirect) purchaser plaintiffs. On July 3, 2015, defendants filed motions to dismiss the consolidated amended complaints, as well as the complaints of the “Opt-Out Plaintiffs” (Walgreen Co., The Kruger Co., Safeway Inc., HEB Grocery Company L.P., Albertson’s LLC, Rite Aid Corporation and Rite Aid Hdqtrs. Corp.). On February 1, 2016, CVS Pharmacy, Inc. filed a complaint in the United States District Court for the Northern District of Illinois. The parties agreed that CVS Pharmacy, Inc. would be bound by the court’s ruling on the defendants’ motion to dismiss the Opt-Out Plaintiffs’ complaints. On February 10, 2016, the court granted in part and denied in part defendants’ motion to dismiss the end-payor purchaser plaintiffs’ consolidated amended complaint, and denied defendants’ motion to dismiss the direct purchaser plaintiffs’ consolidated amended complaint. The end-payor purchaser plaintiffs have filed a second consolidated amended complaint and the Company has moved to dismiss certain state law claims. On February 25, 2016, the court granted defendants’ motion to dismiss the Opt-Out Plaintiffs’ complaints, with leave to amend. The Opt-Out Plaintiffs and CVS Pharmacy, Inc. have filed amended complaints and the Company has filed its answer. Discovery is ongoing. No trial date has been scheduled. Civil Investigation Demand from the Attorney General of the State of Alaska On February 10, 2015, the Company received three CIDs from the Office of the Attorney General of the State of Alaska (“Alaska AG”) concerning its investigations into the drugs Adderall XR ® , Effexor XR ® and Opana ® ER (each a “Product” and collectively, the “Products”) and their generic equivalents. According to the Alaska AG, the investigation is to determine whether the Company may have violated Alaskan state law by entering into settlement agreements with the respective brand name manufacturer for each of the foregoing Products that delayed generic entry of such Product into the marketplace. The Company has cooperated with the Alaska AG in producing documents and information in response to the CIDs. To the knowledge of the Company, no proceedings have been initiated against the Company at this time, however no assurance can be given as to the timing or outcome of this investigation. United States Department of Justice Investigations Previously on November 6, 2014, the Company disclosed that one of its sales representatives received a grand jury subpoena from the Antitrust Division of the United States Justice Department (the “Justice Department”). In connection with this same investigation, on March 13, 2015, the Company received a grand jury subpoena from the Justice Department requesting the production of information and documents regarding the sales, marketing, and pricing of certain generic prescription medications. In particular, the Justice Department’s investigation currently focuses on four generic medications: digoxin tablets, terbutaline sulfate tablets, prilocaine/lidocaine cream, and calcipotriene topical solution. The Company has been cooperating and intends to continue cooperating with the investigation. However, no assurance can be given as to the timing or outcome of the investigation. Attorney General of the State of Connecticut Interrogatories and Subpoena Duces Tecum On July 14, 2014, the Company received a subpoena and interrogatories (the “Subpoena”) from the State of Connecticut Attorney General (“Connecticut AG”) concerning its investigation into sales of the Company’s generic product, digoxin. According to the Connecticut AG, the investigation is to determine whether anyone engaged in a contract, combination or conspiracy in restraint of trade or commerce which has the effect of (i) fixing, controlling or maintaining prices or (ii) allocating or dividing customers or territories relating to the sale of digoxin in violation of Connecticut state antitrust law. The Company intends to cooperate with the Connecticut AG in producing documents and information in response to the Subpoena. To the knowledge of the Company, no proceedings by the Connecticut AG have been initiated against the Company at this time, however no assurance can be given as to the timing or outcome of this investigation. Generic Drug Pricing Class Action On March 2, 2016, the International Union of Operating Engineers Local 30 Benefits Fund filed a class action lawsuit against the Company in the United States District Court for the Eastern District of Pennsylvania, alleging that the Company, in concert with others, engaged in a conspiracy to fix, maintain, and stabilize the price of digoxin in violation of federal and state antitrust law. To date, eight additional putative class action complaints containing similar allegations have been filed against the Company. On March 25, 2016, the Tulsa Firefighters Health and Welfare Trust and the NECA-IBEW Welfare Trust Fund filed complaints in the United States District Court for the Eastern District of Pennsylvania. On April 4, 2016, Pipe Trade Services MN filed a complaint in the United States District Court for the Eastern District of Pennsylvania. On April 25, 2016, Edward Carpinelli filed a complaint in the United States District Court for the Eastern District of Pennsylvania. On April 27, 2016, Fraternal Order of Police, Miami Lodge 20, Insurance Trust Fund filed a complaint in the United States District Court for the Eastern District of Pennsylvania. On May 2, 2016, Nina Diamond filed a complaint in the United States District Court for the Eastern District of Pennsylvania. On May 5, 2016, UFCW Local 1500 Welfare Fund filed a complaint in the Eastern District of Pennsylvania. On May 6, 2016, Minnesota Laborers Health & Welfare Fund filed a complaint in the United States District Court for the Eastern District of Pennsylvania. Discovery in these proceedings has not commenced. AWP Actions On December 30, 2015, Plumbers’ Local Union No. 690 Health Plan and others similarly situated filed a class action against several generic drug manufacturers, including the Company, in the Court of Common Pleas of Philadelphia County, First Judicial District of Pennsylvania, Civil Trial Division, alleging that the Company and others violated the law, including the Pennsylvania Unfair Trade Practices and Consumer Protection law, by inflating the Average Wholesale Price (“AWP”) of certain generic drugs. The case has since been removed to federal court in the United States District Court for the Eastern District of Pennsylvania. By virtue of an amended complaint filed on March 29, 2016, the suit has been amended to comprise a nationwide class of third party payors that allegedly reimbursed or purchased certain generic drugs based on AWP and to assert causes of action under the laws of other states in addition to Pennsylvania. On February 5, 2016, Delaware Valley Health Care Coalition filed a lawsuit based on substantially similar allegations in the Court of Common Pleas of Philadelphia County, First Judicial District of Pennsylvania, Civil Trial Division that seeks declaratory judgment. CID from the U.S. Attorney Office, Southern District of New York On March 8, 2016, the Company received a CID from the U.S. Attorney Office, Southern District of New York, Civil Frauds Unit. The CID requests information and documents relating to the Company and any pharmacy benefit manager (“PBM”) concerning Zomig®, including any contracts between the Company and PBMs, as well as services performed by and payments to the PBMs pursuant to those contracts. The Company intends to cooperate with the U.S. Attorney Office in response to the CID. To the knowledge of the Company, no proceedings by the U.S. Attorney Office have been initiated against the Company at this time; however, no assurance can be given as to the timing or outcome of this investigation. Impax Laboratories, Inc. v. Turing Pharmaceuticals AG On May 2, 2016, the Company filed suit against Turing Pharmaceuticals AG ("Turing") in the United States District Court for the Southern District of New York alleging breach of the terms of the contract by which Turing purchased from the Company the right to sell the drug Daraprim®, as well as the right to sell certain Daraprim® inventory (the “Purchase Agreement”). Specifically, the Company seeks (i) a declaratory judgment that the Company may revoke Turing’s right to sell Daraprim® under the Company’s labeler code and national drug codes; (ii) specific performance to require Turing to comply with its obligations under the Purchase Agreement for past due reports and for reports going forward; and (iii) money damages to remedy Turing’s failure to reimburse the Company for in excess of $20 million of chargebacks and Medicaid rebate liability when due and for future amounts that may be due.

SEGMENT INFORMATION

SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION The Company has two reportable segments, Impax Generics and Impax Specialty Pharma. Impax Generics develops, manufactures, sells, and distributes generic pharmaceutical products, primarily through the following sales channels: the Impax Generics sales channel for sales of generic prescription products directly to wholesalers, large retail drug chains, and others; the Private Label Product sales channel for generic over-the-counter and prescription products sold to unrelated third-party customers who, in turn, sell the products under their own label; the Rx Partner sales channel for generic prescription products sold through unrelated third-party pharmaceutical entities under their own label pursuant to alliance agreements; and the OTC Partner sales channel for over-the-counter products sold through unrelated third-party pharmaceutical entities under their own labels pursuant to alliance and supply agreements. Revenues from the “Impax Generics” sales channel and the “Private Label” sales channel are reported under the caption “Impax Generics sales, net” in “Note 23. Supplementary Financial Information.” The Company also generates revenue in Impax Generics from research and development services provided under a joint development agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” revenue in “Note 23. Supplementary Financial Information.” Revenues from the “OTC Partner” sales channel are also reported under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma is engaged in the development, sale and distribution of proprietary brand pharmaceutical products that the Company believes represent improvements to already-approved pharmaceutical products addressing central nervous system (“CNS”) disorders and other select specialty segments. Impax Specialty Pharma currently has one internally developed branded pharmaceutical product, Rytary® (IPX066), an extended release oral capsule formulation of carbidopa-levodopa for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication and/or manganese intoxication, which was approved by the FDA on January 7, 2015 and which the Company launched in April 2015. In November 2015, the European Commission granted marketing authorization for NUMIENT™ (IPX066) (referred to as Rytary® in the United States). The review of the NUMIENT™ application was conducted under the centralized licensing procedure as a therapeutic innovation, and authorization is applicable in all 28 member states of the European Union, as well as Iceland, Liechtenstein and Norway. Impax Specialty Pharma is also engaged in the sale and distribution of four other branded products including Zomig® (zolmitriptan) products, indicated for the treatment of migraine headaches, under the terms of the AZ Agreement with AstraZeneca in the United States and in certain U.S. territories, and EMVERM TM (mebendazole) 100 mg chewable tablets, indicated for the treatment of pinworn, whipworm, common roundworm, common hookworm, and American hookworm in single or mixed infections. Revenues from Impax-labeled branded products are reported under the caption “Impax Specialty Pharma sales, net” in “Note 23. Supplementary Financial Information.” Finally, the Company generates revenue in Impax Specialty Pharma from research and development services provided under a development and license agreement with another unrelated third-party pharmaceutical company, and reports such revenue under the caption “Other Revenues” in “Note 23. Supplementary Financial Information.” Impax Specialty Pharma also has a number of product candidates that are in varying stages of development. The Company’s chief operating decision maker evaluates the financial performance of the Company’s segments based upon segment income (loss) before income taxes. Items below income (loss) from operations are not reported by segment, since they are excluded from the measure of segment profitability reviewed by the Company’s chief operating decision maker. Additionally, general and administrative expenses, certain selling expenses, certain litigation settlements, and non-operating income and expenses are included below in “Corporate and Other.” The Company does not report balance sheet information by segment since it is not reviewed by the Company’s chief operating decision maker. The accounting policies for the Company’s segments are the same as those described above in the discussion of "Revenue Recognition" in “Note 4. Summary of Significant Accounting Policies.” The Company has no inter-segment revenue. The tables below present segment information reconciled to total Company financial results, with segment operating income or loss including gross profit less direct research and development expenses and direct selling expenses as well as any litigation settlements, to the extent specifically identified by segment (in thousands): Three Months Ended March 31, 2016 Impax Generics Impax Corporate and Other Total Company Revenues, net $ 170,079 $ 55,429 $ — $ 225,508 Cost of revenues $ 110,122 $ 12,796 $ — $ 122,918 Selling, general and administrative $ 4,774 $ 13,818 $ 25,706 $ 44,298 Research and development $ 14,595 $ 4,427 $ — $ 19,022 Patent litigation expense $ 114 $ 1,205 $ — $ 1,319 Income (loss) before income taxes $ 40,474 $ 23,183 $ (81,151 ) $ (17,494 ) Three Months Ended March 31, 2015 Impax Generics Impax Specialty Pharma Corporate and Other Total Company Revenues, net $ 128,741 $ 14,355 $ — $ 143,096 Cost of revenues $ 76,472 $ 7,390 $ — $ 83,862 Selling, general and administrative $ 4,286 $ 14,856 $ 31,018 $ 50,160 Research and development $ 10,863 $ 4,099 $ — $ 14,962 Patent litigation expense $ 778 $ 182 $ — $ 960 Income (loss) before income taxes $ 36,342 $ (12,172 ) $ (34,875 ) $ (10,705 ) Foreign Operations The Company’s wholly-owned subsidiary, Impax Laboratories (Taiwan) Inc., has constructed a facility in Taiwan which is utilized for manufacturing, research and development, warehouse, and administrative functions, with $134.7 million and $131.6 million of net carrying value of assets, composed principally of a building and equipment, included in the Company's consolidated balance sheets at March 31, 2016 and December 31, 2015 , respectively.

SUPPLEMENTARY FINANCIAL INFORMA

SUPPLEMENTARY FINANCIAL INFORMATION (unaudited)	3 Months Ended
	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
SUPPLEMENTARY FINANCIAL INFORMATION	SUPPLEMENTARY FINANCIAL INFORMATION (unaudited) Selected financial information for the quarterly period noted is as follows: (in thousands, except share and per share amounts) Quarter Ended March 31, 2016 Revenue: Impax Generic Product sales, gross $ 611,281 Less: Chargebacks 217,354 Rebates 185,476 Product Returns 11,913 Other credits 29,354 Impax Generic Product sales, net 167,184 Rx Partner 2,835 Other Revenues 60 Impax Generic Division revenues, net 170,079 Impax Specialty Pharma sales, gross 82,073 Less: Chargebacks 6,111 Rebates 2,853 Product Returns 1,508 Other credits 16,172 Impax Specialty Pharma sales, net 55,429 Other Revenues — Impax Specialty Pharma revenues, net 55,429 Total revenues 225,508 Gross profit 102,590 Net loss $ (10,408 ) Net loss per common share: Basic $ (0.15 ) Diluted $ (0.15 ) Weighted-average common shares outstanding: Basic 70,665,394 Diluted 70,665,394 (in thousands, except share and per share amounts) Quarter Ended March 31, 2015 Revenue: Impax Generic Product sales, gross $ 355,321 Less: Chargebacks 126,607 Rebates 83,130 Product Returns 6,427 Other credits 13,198 Impax Generic Product sales, net 125,959 Rx Partner 2,239 Other Revenues 543 Impax Generic Division revenues, net 128,741 Impax Specialty Pharma sales, gross 29,219 Less: Chargebacks 5,561 Rebates 2,132 Product Returns 2,620 Other credits 4,778 Impax Specialty Pharma sales, net 14,128 Other Revenues 227 Impax Specialty Pharma revenues, net 14,355 Total revenues 143,096 Gross profit 59,234 Net loss $ (6,333 ) Net loss per common share: Basic $ (0.09 ) Diluted $ (0.09 ) Weighted-average common shares outstanding: Basic 68,967,875 Diluted 68,967,875

SUMMARY OF SIGNIFICANT ACCOUN30

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Revenue Recognition, Policy	Revenue Recognition The Company recognizes revenue when the earnings process is complete, which under SEC Staff Accounting Bulletin No. 104, Topic No. 13, “Revenue Recognition” (“SAB 104”), is when revenue is realized or realizable and earned, there is persuasive evidence a revenue arrangement exists, delivery of goods or services has occurred, the sales price is fixed or determinable, and collectability is reasonably assured. The Company accounts for material revenue arrangements which contain multiple deliverables in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 605-25, Revenue Recognition - Multiple-Element Arrangements ("ASC 605-25"), which addresses the determination of whether an arrangement involving multiple deliverables contains more than one unit of accounting. A delivered item within an arrangement is considered a separate unit of accounting only if both of the following criteria are met: • the delivered item has value to the customer on a stand-alone basis; and • if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially in the control of the vendor. Under ASC 605-25, if both of the criteria above are not met, then separate accounting for the individual deliverables is not appropriate. Revenue recognition for arrangements with multiple deliverables constituting a single unit of accounting is recognized generally over the greater of the term of the arrangement or the expected period of performance, either on a straight-line basis or on a modified proportional performance method. The Company accounts for milestones related to research and development activities in accordance with FASB ASC Topic 605-28, Revenue Recognition - Milestone Method ("ASC 605-28"). ASC 605-28 allows for the recognition of consideration, which is contingent on the achievement of a substantive milestone, in its entirety in the period the milestone is achieved. A milestone is considered to be substantive if all of the following criteria are met: • the milestone is commensurate with either (1) the performance required to achieve the milestone or (2) the enhancement of the value of the delivered items resulting from the performance required to achieve the milestone; • the milestone relates solely to past performance; and • the milestone payment is reasonable relative to all of the deliverables and payment terms within the agreement. Impax Generics revenues, net and Impax Specialty Pharma revenues, net The Impax Generics revenues, net and Impax Specialty Pharma revenues, net include revenue recognized related to shipments of generic and branded pharmaceutical products to the Company’s customers, primarily drug wholesalers and retail chains. Gross sales revenue is recognized at the time title and risk of loss passes to the customer, which is generally when product is received by the customer. Net revenues may include deductions from the gross sales price related to estimates for chargebacks, rebates, distribution service fees, returns, shelf-stock adjustments, and other pricing adjustments. The Company records an estimate for these deductions in the same period when revenue is recognized. A description of each of these gross-to-net deductions follows. • Chargebacks The Company has agreements establishing contract prices for certain products with certain indirect customers, such as managed care organizations, hospitals and government agencies who purchase products from drug wholesalers. The contract prices are lower than the prices the customer would otherwise pay to the wholesaler, and the price difference is referred to as a chargeback, which generally takes the form of a credit memo issued by the Company to reduce the invoiced gross selling price charged to the wholesaler. An estimated accrued provision for chargeback deductions is recognized at the time of product shipment. The primary factors considered when estimating the provision for chargebacks are the average historical chargeback credits given, the mix of products shipped, and the amount of inventory on hand at the major drug wholesalers with whom the Company does business. The Company also monitors actual chargebacks granted and compares them to the estimated provision for chargebacks to assess the reasonableness of the chargeback reserve at each quarterly balance sheet date. • Rebates The Company maintains various rebate programs with its customers in an effort to maintain a competitive position in the marketplace and to promote sales and customer loyalty. The rebates generally take the form of a credit memo to reduce the invoiced gross selling price charged to a customer for products shipped. An estimated accrued provision for rebate deductions is recognized at the time of product shipment. The primary factors the Company considers when estimating the provision for rebates are the average historical experience of aggregate credits issued, the mix of products shipped and the historical relationship of rebates as a percentage of total gross product sales, the contract terms and conditions of the various rebate programs in effect at the time of shipment, and the amount of inventory on hand at the major drug wholesalers with whom the Company does business. The Company also monitors actual rebates granted and compares them to the estimated provision for rebates to assess the reasonableness of the rebate reserve at each quarterly balance sheet date. • Distribution Service Fees The Company pays distribution service fees to several of its wholesaler customers related to sales of its Impax Products. The wholesalers are generally obligated to provide the Company with periodic outbound sales information as well as inventory levels of the Company’s Impax Products held in their warehouses. Additionally, the wholesalers have agreed to manage the variability of their purchases and inventory levels within specified days on hand limits. An accrued provision for distribution service fees is recognized at the time products are shipped to wholesalers. • Returns The Company allows its customers to return product if approved by authorized personnel in writing or by telephone with the lot number and expiration date accompanying any request and if such products are returned within six months prior to or until twelve months following, the product’s expiration date. The Company estimates and recognizes an accrued provision for product returns as a percentage of gross sales based upon historical experience. The product return reserve is estimated using a historical lag period, which is the time between when the product is sold and when it is ultimately returned, and estimated return rates which may be adjusted based on various assumptions including: changes to internal policies and procedures, business practices, commercial terms with customers, and the competitive position of each product; the amount of inventory in the wholesale and retail supply chain; the introduction of new products; and changes in market sales information. The Company also considers other factors, including significant market changes which may impact future expected returns and actual product returns. The Company monitors actual returns on a quarterly basis and may record specific provisions for returns it believes are not covered by historical percentages. • Shelf-Stock Adjustments Based upon competitive market conditions, the Company may reduce the selling price of certain Impax Generics division products. The Company may issue a credit against the sales amount to a customer based upon their remaining inventory of the product in question, provided the customer agrees to continue to make future purchases of product from the Company. This type of customer credit is referred to as a shelf-stock adjustment, which is the difference between the initial sales price and the revised lower sales price, multiplied by an estimate of the number of product units on hand at a given date. Decreases in selling prices are discretionary decisions made by the Company in response to market conditions, including estimated launch dates of competing products and declines in market price. The Company records an estimate for shelf-stock adjustments in the period it agrees to grant such a credit memo to a customer. • Cash Discounts The Company offers cash discounts to its customers, generally 2% to 3% of the gross selling price, as an incentive for paying within invoice terms, which generally range from 30 to 90 days. An estimate of cash discounts is recorded in the same period when revenue is recognized. • Medicaid and Other U.S. Government Pricing Programs As required by law, the Company provides a rebate on drugs dispensed under the Medicaid program, Medicare Part D, TRICARE, and other U.S. government pricing programs. The Company determines its estimated government rebate accrual primarily based on historical experience of claims submitted by the various states and other jurisdictions and any new information regarding changes in the various programs which may impact the Company’s estimate of government rebates. In determining the appropriate accrual amount, the Company considers historical payment rates and processing lag for outstanding claims and payments. The Company records estimates for government rebates as a deduction from gross sales, with a corresponding adjustment to accrued liabilities. • Rx Partner and OTC Partner The Rx Partner and OTC Partner contracts include revenue recognized under alliance and collaboration agreements between the Company and unrelated third-party pharmaceutical companies. The Company has entered into these alliance agreements to develop marketing and/or distribution relationships with its partners to fully leverage its technology platform. The Rx Partners and OTC Partners alliance agreements obligate the Company to deliver multiple goods and/or services over extended periods. Such deliverables include manufactured pharmaceutical products, exclusive and semi-exclusive marketing rights, distribution licenses, and research and development services. In exchange for these deliverables the Company receives payments from its agreement partners for product shipments and research and development services, and may also receive other payments including royalties, profit sharing payments, and upfront and periodic milestone payments. Revenue received from the alliance agreement partners for product shipments under these agreements is not subject to deductions for chargebacks, rebates, product returns, and other pricing adjustments. Royalty and profit sharing amounts the Company receives under these agreements are calculated by the respective agreement partner, with such royalty and profit share amounts generally based upon estimates of net product sales or gross profit which include estimates of deductions for chargebacks, rebates, product returns, and other adjustments the alliance agreement partners may negotiate with their respective customers. The Company records the agreement partner's adjustments to such estimated amounts in the period the agreement partner reports the amounts to the Company. The Company applies the guidance of ASC 605-25 to the Strategic Alliance Agreement, as amended, with Teva Pharmaceuticals Curacao N.V., a subsidiary of Teva Pharmaceutical Industries Limited (the “Teva Agreement”). The Company looks to the underlying delivery of goods and/or services which give rise to the payment of consideration under the Teva Agreement to determine the appropriate revenue recognition. The Company initially defers consideration received as a result of research and development-related activities performed under the Teva Agreement. The Company recognizes deferred revenue on a straight-line basis over the expected period of performance for such services. Consideration received as a result of the manufacture and delivery of products under the Teva Agreement is recognized at the time title and risk of loss passes to the customer, which is generally when product is received by Teva. The Company recognizes profit share revenue in the period earned. OTC Partner revenue is related to agreements with Pfizer, Inc., formerly Wyeth LLC (“Pfizer”) and L. Perrigo Company (“Perrigo”) with respect to the supply of over-the-counter pharmaceutical products. The OTC Partner sales channel is no longer a core area of the business, and the over-the-counter pharmaceutical products the Company sells through this sales channel are older products which are only sold to Pfizer and Perrigo. The Company is currently only required to manufacture the over-the-counter pharmaceutical products under its agreements with Pfizer and Perrigo. The Company recognizes profit share revenue in the period earned. • Research Partner The Research Partner contract revenue results from development agreements the Company enters into with unrelated third-party pharmaceutical companies. The development agreements generally obligate the Company to provide research and development services over multiple periods. In exchange for this service, the Company generally receives upfront payments upon signing of each development agreement and is eligible to receive contingent milestone payments, payment of which is based upon the achievement of contractually specified events. Additionally, the Company may also receive royalty payments from the sale, if any, of a successfully developed and commercialized product under one of these development agreements. The Company recognizes revenue received from the achievement of contingent research and development milestones in the period such payment is earned. Royalty revenue, if any, will be recognized as current period revenue when earned.
Concentration Risk, Credit Risk, Policy	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are cash, cash equivalents, and accounts receivable. The Company limits its credit risk associated with cash and cash equivalents by placing its investments with high quality money market funds, corporate debt, and short-term commercial paper and in securities backed by the U.S. Government. The Company limits its credit risk with respect to accounts receivable by performing credit evaluations when deemed necessary. The Company does not require collateral to secure amounts owed to it by its customers. In July 2015, the Company received an unsolicited offer from Turing Pharmaceuticals AG (“Turing”) to purchase the U.S. rights to Daraprim®, one of the marketed products acquired in the Tower acquisition, as well as the active pharmaceutical ingredient for the product and the finished goods inventory on hand. Pursuant to the terms of the Asset Purchase Agreement between the Company and Turing dated August 7, 2015 (the “Turing APA”), the Company also granted a limited license to sell the existing Daraprim® product under the Company’s labeler code with the Company’s trade dress. The sale closed on August 7, 2015. In accordance with the terms of the Turing APA and in accordance with federal laws and regulations, the Company received, and is initially responsible for processing and paying (subject to reimbursement by Turing), all chargebacks and rebates resulting from utilization by Medicaid, Medicare and other federal, state and local governmental programs, health plans and other health care providers for product sold under the Company’s labeler code. Under the terms of the Turing APA, Turing is responsible for liabilities related to chargebacks and rebates that arise as a result of Turing’s marketing or selling related activities in connection with Daraprim®.
New Accounting Pronouncements, Policy	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued Accounting Standards Update ("ASU") 2014-09, “Revenue from Contracts with Customers” (Topic 606) regarding the accounting for and disclosures of revenue recognition, with an effective date for annual and interim periods beginning after December 15, 2016. This update provides a single comprehensive model for accounting for revenue from contracts with customers. The model requires that revenue recognized reflect the actual consideration to which the entity expects to be entitled in exchange for the goods or services defined in the contract, including in situations with multiple performance obligations. In July 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date”, which deferred the effective date, of the previously issued revenue recognition guidance by one year. The guidance will be effective for annual and interim periods beginning after December 15, 2017. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In July 2015, the FASB issued ASU 2015-11, Inventory (Topic 330): “Simplifying the Measurement of Inventory”, with guidance regarding the accounting for and measurement of inventory. The update requires that inventory measured using first-in, first-out (FIFO) shall be measured at the lower of cost and net realizable value. When there is evidence that the net realizable value of inventory is lower than its cost, the difference shall be recognized as a loss in earnings in the period in which it occurs. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In September 2015, the FASB issued ASU 2015-16, Business Combinations (Topic 805): “Simplifying the Accounting for Measurement-Period Adjustments”, with guidance regarding the accounting for and disclosure of measurement-period adjustments that occur in periods after a business combination is consummated. This update requires that the acquirer recognize measurement-period adjustments in the reporting period in which they are determined and, as such, eliminates the previous requirement to retrospectively account for these adjustments. This update also requires an entity to present separately on the face of the income statement, or disclose in the notes, the amount recorded in the current-period income statement that would have been recorded in previous reporting periods if the adjustments had been recognized as of the acquisition date. The effective date for annual and interim periods begins after December 15, 2015. The Company adopted this guidance during 2016, and it did not have a material effect on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), with guidance regarding the accounting for and disclosure of leases. The update requires lessees to recognize all leases, including operating leases, with a term greater than 12 months on the balance sheet. This update also requires lessees and lessors to disclose key information about their leasing transactions. The guidance will be effective for annual and interim periods beginning after December 15, 2018. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-06, Contingent Put and Call Options in Debt Instruments (Topic 815), with guidance regarding the accounting for embedded derivatives related to debt contracts. The update clarifies that determining whether the economic characteristics of a put or call are clearly and closely related to its debt host requires only an assessment of the four-step decision sequence outlined in FASB ASC paragraph 815-15-25-24. The update also indicates that entities are not required to separately assess whether the contingency itself is clearly and closely related. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting (Topic 718), with guidance regarding the simplification of accounting for share-based payment award transactions. The update changes the accounting for such areas as the accounting and cash flow classification for excess tax benefits and deficiencies; forfeitures; and tax withholding requirements and cash flow classification. The guidance will be effective for annual and interim periods beginning after December 15, 2016. The Company is currently evaluating the effect that this guidance may have on its consolidated financial statements.

BUSINESS ACQUISITION (Tables)

BUSINESS ACQUISITION (Tables)	3 Months Ended
	Mar. 31, 2016
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following tables summarize the final fair values of the tangible and identifiable intangible assets acquired and liabilities assumed in the transaction at the acquisition date, net of cash acquired of $41.5 million (in thousands): Accounts receivable (1) $ 56,851 Inventory 31,259 Income tax receivable and other prepaid expenses 2,407 Deferred income taxes 37,041 Property, plant and equipment 27,540 Intangible assets 632,600 Intangible assets held for sale 4,000 Goodwill 180,808 Other non-current assets 3,844 Total assets assumed 976,350 Current liabilities 67,706 Other non-current liabilities 7,291 Deferred tax liabilities 210,005 Total liabilities assumed 285,002 Cash paid, net of cash acquired (2) $ 691,348 (1) The accounts receivable acquired in the Tower acquisition had a fair value of $56.9 million , net of an allowance for doubtful accounts of $9.0 million , which represented the Company’s best estimate on March 9, 2015 (the closing date of the transaction) of the contractual cash flows not expected to be collected by the acquired companies. (2) The initial net purchase price of $697.2 million was subject to post-closing working capital adjustments, which resulted in the return of $5.9 million to the Company during the third quarter of 2015.
Schedule of Finite-Lived Intangible Assets	The following tables show the gross carrying values and accumulated amortization, where applicable, of the Company’s intangible assets by type for the Company’s consolidated balance sheets presented (in thousands): March 31, 2016 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 544,976 $ (91,618 ) $ 453,358 Royalties 2,200 (246 ) 1,954 547,176 (91,864 ) 455,312 Non-amortized intangible assets: Acquired IPR&D product rights 62,840 — 62,840 Acquired future royalty rights 78,600 — 78,600 141,440 — 141,440 Total intangible assets $ 688,616 $ (91,864 ) $ 596,752 December 31, 2015 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 458,675 $ (82,906 ) $ 375,769 Royalties 2,200 (189 ) 2,011 460,875 (83,095 ) 377,780 Non-amortized intangible assets: Acquired IPR&D product rights 145,640 — 145,640 Acquired future royalty rights 78,600 — 78,600 224,240 — 224,240 Total intangible assets $ 685,115 $ (83,095 ) $ 602,020
Business Acquisition, Pro Forma Information	The following table reflects the unaudited pro forma combined results of operations for the three months ended March 31, 2015 (assuming the closing of the Tower acquisition occurred on January 1, 2014) (in thousands): Three Months Ended March 31, 2015 Total revenues $ 175,533 Net loss $ (6,595 )
Tower And Lineage
Business Acquisition [Line Items]
Schedule of Finite-Lived Intangible Assets	The following table identifies the Company’s allocations, by category, of the Tower purchase price to the intangible assets acquired: Estimated Fair Weighted-Average (years) Currently marketed product rights $ 381,100 13 Current and future royalty rights 80,800 12 In-process research and development product rights 170,700 n/a Total intangible assets $ 632,600 12

FAIR VALUE MEASUREMENT AND FI32

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The carrying amounts and fair values of the Company’s financial instruments at March 31, 2016 and December 31, 2015 are indicated below (in thousands): As of March 31, 2016 Fair Value Measurement Based on Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Deferred Compensation Plan assets (1) $ 30,733 $ 30,733 $ — $ 30,733 $ — Liabilities 2% Convertible senior notes due June 2022 (2) $ 600,000 $ 536,472 $ 536,472 $ — $ — Deferred Compensation Plan liabilities (1) $ 27,766 $ 27,766 $ — $ 27,766 $ — As of December 31, 2015 Fair Value Measurement Based on Carrying Amount Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Deferred Compensation Plan assets (1) $ 30,726 $ 30,726 $ — $ 30,726 $ — Liabilities 2% Convertible senior notes due June 2022 (2) $ 600,000 $ 602,250 $ 602,250 $ — $ — Deferred Compensation Plan liabilities (1) $ 25,581 $ 25,581 $ — $ 25,581 $ — (1) The Deferred Compensation Plan liabilities are non-current liabilities recorded at the value of the amount owed to the plan participants, with changes in value recognized as compensation expense in the Company’s consolidated statements of operations. The calculation of the Deferred Compensation Plan obligation is derived from observable market data by reference to hypothetical investments selected by the participants and is included in the line items captioned “Other non-current liabilities” on the Company’s consolidated balance sheets. The Company invests participant contributions in corporate-owned life insurance (“COLI”) policies, for which the cash surrender value is included in the line item captioned “Other non-current assets” on the Company’s consolidated balance sheets. (2) The difference between the amount shown as the carrying value in the above tables and the amount shown on the Company’s consolidated balance sheets at March 31, 2016 and December 31, 2015 represents the unaccreted discounts related to deferred debt issuance costs and bifurcation of the conversion feature of the notes.

ACCOUNTS RECEIVABLE (Tables)

ACCOUNTS RECEIVABLE (Tables)	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The composition of accounts receivable, net is as follows (in thousands): March 31, 2016 December 31, 2015 Gross accounts receivable (1) $ 729,060 $ 738,730 Less: Rebate reserve (320,013 ) (265,229 ) Less: Chargeback reserve (104,293 ) (102,630 ) Less: Distribution services reserve (11,638 ) (12,576 ) Less: Discount reserve (15,469 ) (18,657 ) Less: Uncollectible accounts reserve (2) (63,199 ) (15,187 ) Accounts receivable, net $ 214,448 $ 324,451 (1) Includes estimated $48.0 million and $40.6 million as of March 31, 2016 and December 31, 2015, respectively, receivable due from Turing for reimbursement of Daraprim® chargebacks and Medicaid rebate liabilities. (2) As a result of the uncertainty of collection that has developed since the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2015, the Company recorded a reserve of $48.0 million as of March 31, 2016, which represents the full amount of the estimated receivable due from Turing as of that date. See "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" for additional information regarding the Turing receivable.
Allowance for Credit Losses on Financing Receivables	A roll-forward of the rebate and chargeback reserves activity for the three months ended March 31, 2016 and the year ended December 31, 2015 is as follows (in thousands): Rebate reserve March 31, 2016 December 31, 2015 Beginning balance $ 265,229 $ 88,812 Acquired balances — 75,447 Provision recorded during the period for Impax Generics rebates 185,476 571,642 Credits issued during the period for Impax Generics rebates (130,692 ) (470,672 ) Ending balance $ 320,013 $ 265,229 The payment mechanisms for rebates in the Impax Generics and Impax Specialty Pharma divisions are different, which impacts the location on the Company's balance sheet. Impax Specialty Pharma rebates are classified as Accrued Expenses on the Company's consolidated balance sheets. Chargeback reserve March 31, 2016 December 31, 2015 Beginning balance $ 102,630 $ 43,125 Acquired balances — 24,532 Provision recorded during the period 223,465 833,157 Credits issued during the period (221,802 ) (798,184 ) Ending balance $ 104,293 $ 102,630

INVENTORY (Tables)

INVENTORY (Tables)	3 Months Ended
	Mar. 31, 2016
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	Inventory, net of carrying value reserves, at March 31, 2016 and December 31, 2015 consisted of the following (in thousands): March 31, 2016 December 31, 2015 Raw materials $ 57,065 $ 52,366 Work in-process 5,935 4,417 Finished goods 89,827 82,311 Total inventory 152,827 139,094 Less: Non-current inventory 19,264 13,512 Total current inventory $ 133,563 $ 125,582

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment, net of accumulated depreciation, consists of the following (in thousands): March 31, 2016 December 31, 2015 Land $ 5,603 $ 5,773 Buildings and improvements 169,400 165,322 Equipment 136,599 135,998 Office furniture and equipment 14,975 14,548 Construction in-progress 30,238 25,659 Property, plant and equipment, gross 356,815 347,300 Less: Accumulated depreciation (137,415 ) (133,144 ) Property, plant and equipment, net $ 219,400 $ 214,156

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL (Tables)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following tables show the gross carrying values and accumulated amortization, where applicable, of the Company’s intangible assets by type for the Company’s consolidated balance sheets presented (in thousands): March 31, 2016 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 544,976 $ (91,618 ) $ 453,358 Royalties 2,200 (246 ) 1,954 547,176 (91,864 ) 455,312 Non-amortized intangible assets: Acquired IPR&D product rights 62,840 — 62,840 Acquired future royalty rights 78,600 — 78,600 141,440 — 141,440 Total intangible assets $ 688,616 $ (91,864 ) $ 596,752 December 31, 2015 Gross Carrying Value Accumulated Amortization Intangible Assets, Net Amortized intangible assets: Marketed product rights $ 458,675 $ (82,906 ) $ 375,769 Royalties 2,200 (189 ) 2,011 460,875 (83,095 ) 377,780 Non-amortized intangible assets: Acquired IPR&D product rights 145,640 — 145,640 Acquired future royalty rights 78,600 — 78,600 224,240 — 224,240 Total intangible assets $ 685,115 $ (83,095 ) $ 602,020

ACCRUED EXPENSES (Tables)

ACCRUED EXPENSES (Tables)	3 Months Ended
	Mar. 31, 2016
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	The following table sets forth the Company’s accrued expenses (in thousands): March 31, 2016 December 31, 2015 Payroll-related expenses $ 23,500 $ 37,419 Product returns 56,044 48,950 Accrued shelf stock 9,995 6,619 Government rebates (1) 99,606 91,717 Legal and professional fees 8,965 5,929 Income taxes payable 2,558 830 Physician detailing sales force fees 327 1,132 Interest payable 3,500 500 Other 8,617 11,615 Total accrued expenses $ 213,112 $ 204,711 (1) Includes estimated $42.9 million and $40.6 million as of March 31, 2016 and December 31, 2015, respectively, of liabilities for Daraprim® chargebacks and rebates resulting from utilization by Medicaid, Medicare and other federal, state and local governmental programs, health plans and other health care providers for product sold under the Company’s labeler code, which amounts are subject to reimbursement by Turing in accordance with the terms of the Company's purchase agreement with Turing. The Company made payments of $5.1 million on Turing's behalf during the first quarter of 2016. See "Note 4. Summary of Significant Accounting Policies - Concentration of Credit Risk" for additional information related to the Turing receivable.
Schedule of Product Warranty Liability	A roll-forward of the return reserve activity for the three months ended March 31, 2016 and the year ended December 31, 2015 is as follows (in thousands): Returns Reserve March 31, 2016 December 31, 2015 Beginning balance $ 48,950 $ 27,174 Acquired balances — 11,364 Provision related to sales recorded in the period 13,421 43,967 Credits issued during the period (6,327 ) (33,555 ) Ending balance $ 56,044 $ 48,950

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity Note [Abstract]
Common Stock Reserved for Future Issuance	In addition, the Company had reserved for issuance the following amounts of shares of its common stock for the purposes described below as of March 31, 2016 (in thousands): Shares issued 73,340 Stock options outstanding (1) 2,480 Conversion of Notes payable (2) 9,471 Warrants outstanding (see below) 9,471 Total shares of common stock issued and reserved for issuance 94,762 (1) See “Note 16. Share-based Compensation.” (2) See “Note 13. Debt.”

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following is a reconciliation of basic and diluted net loss per share of common stock for the three months ended March 31, 2016 and 2015 (in thousands, except per share amounts): Three Months Ended 2016 2015 Basic Loss Per Common Share: Net loss $ (10,408 ) $ (6,333 ) Weighted-average common shares outstanding 70,665 68,968 Basic loss per share $ (0.15 ) $ (0.09 ) Diluted Loss Per Common Share: Net loss $ (10,408 ) $ (6,333 ) Add-back of interest expense on outstanding convertible notes payable, net of tax — (1) — (2) Adjusted net loss $ (10,408 ) $ (6,333 ) Weighted-average common shares outstanding 70,665 68,968 Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance — (3) — (4) Weighted-average incremental shares assuming conversion of outstanding notes payable — (1) — (2) Diluted weighted-average common shares outstanding 70,665 (3) 68,968 (4) Diluted net loss per share $ (0.15 ) $ (0.09 ) (1) For the three month period ended March 31, 2016, the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. Accordingly, there were no numerator or denominator adjustments related to the Company’s convertible notes payable. (2) Not applicable to the period presented. (3) For the three month period ended March 31, 2016 , the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. As of March 31, 2016 , shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, include 9.47 million warrants outstanding, 9.47 million shares for conversion of outstanding convertible notes payable, 2.48 million stock options outstanding and 2.15 million non-vested restricted stock awards. (4) For the three month period ended March 31, 2015, the Company incurred a net loss, which cannot be diluted, so basic and diluted loss per common share were the same. As of March 31, 2015, shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, include 3.16 million stock options outstanding and 2.48 million non-vested restricted stock awards.

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	The stock option activity for all of the Company’s equity compensation plans noted above is summarized as follows: Stock Options Number of Shares Under Option Weighted- Average Exercise Price per Share Outstanding at December 31, 2015 2,405,371 $ 21.39 Options granted 426,390 $ 13.10 Options exercised (351,574 ) $ 20.95 Options forfeited — $ — Outstanding at March 31, 2016 2,480,187 $ 23.50 Options exercisable at March 31, 2016 1,376,812 $ 16.35
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	A summary of the non-vested restricted stock awards is as follows: Restricted Stock Awards Number of Restricted Stock Awards Weighted- Average Grant Date Fair Value Non-vested at December 31, 2015 2,146,498 $ 33.20 Granted 186,264 $ 33.42 Vested (72,690 ) $ 35.67 Forfeited (106,989 ) $ 32.49 Non-vested at March 31, 2016 2,153,083 $ 33.17
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The amount of share-based compensation expense recognized by the Company is as follows (in thousands): Three Months Ended 2016 2015 Manufacturing expenses $ 1,368 $ 1,046 Research and development 1,340 1,365 Selling, general and administrative 4,570 4,077 Total $ 7,278 $ 6,488

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The tables below present segment information reconciled to total Company financial results, with segment operating income or loss including gross profit less direct research and development expenses and direct selling expenses as well as any litigation settlements, to the extent specifically identified by segment (in thousands): Three Months Ended March 31, 2016 Impax Generics Impax Corporate and Other Total Company Revenues, net $ 170,079 $ 55,429 $ — $ 225,508 Cost of revenues $ 110,122 $ 12,796 $ — $ 122,918 Selling, general and administrative $ 4,774 $ 13,818 $ 25,706 $ 44,298 Research and development $ 14,595 $ 4,427 $ — $ 19,022 Patent litigation expense $ 114 $ 1,205 $ — $ 1,319 Income (loss) before income taxes $ 40,474 $ 23,183 $ (81,151 ) $ (17,494 ) Three Months Ended March 31, 2015 Impax Generics Impax Specialty Pharma Corporate and Other Total Company Revenues, net $ 128,741 $ 14,355 $ — $ 143,096 Cost of revenues $ 76,472 $ 7,390 $ — $ 83,862 Selling, general and administrative $ 4,286 $ 14,856 $ 31,018 $ 50,160 Research and development $ 10,863 $ 4,099 $ — $ 14,962 Patent litigation expense $ 778 $ 182 $ — $ 960 Income (loss) before income taxes $ 36,342 $ (12,172 ) $ (34,875 ) $ (10,705 )

SUPPLEMENTARY FINANCIAL INFOR42

SUPPLEMENTARY FINANCIAL INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	(in thousands, except share and per share amounts) Quarter Ended March 31, 2016 Revenue: Impax Generic Product sales, gross $ 611,281 Less: Chargebacks 217,354 Rebates 185,476 Product Returns 11,913 Other credits 29,354 Impax Generic Product sales, net 167,184 Rx Partner 2,835 Other Revenues 60 Impax Generic Division revenues, net 170,079 Impax Specialty Pharma sales, gross 82,073 Less: Chargebacks 6,111 Rebates 2,853 Product Returns 1,508 Other credits 16,172 Impax Specialty Pharma sales, net 55,429 Other Revenues — Impax Specialty Pharma revenues, net 55,429 Total revenues 225,508 Gross profit 102,590 Net loss $ (10,408 ) Net loss per common share: Basic $ (0.15 ) Diluted $ (0.15 ) Weighted-average common shares outstanding: Basic 70,665,394 Diluted 70,665,394 (in thousands, except share and per share amounts) Quarter Ended March 31, 2015 Revenue: Impax Generic Product sales, gross $ 355,321 Less: Chargebacks 126,607 Rebates 83,130 Product Returns 6,427 Other credits 13,198 Impax Generic Product sales, net 125,959 Rx Partner 2,239 Other Revenues 543 Impax Generic Division revenues, net 128,741 Impax Specialty Pharma sales, gross 29,219 Less: Chargebacks 5,561 Rebates 2,132 Product Returns 2,620 Other credits 4,778 Impax Specialty Pharma sales, net 14,128 Other Revenues 227 Impax Specialty Pharma revenues, net 14,355 Total revenues 143,096 Gross profit 59,234 Net loss $ (6,333 ) Net loss per common share: Basic $ (0.09 ) Diluted $ (0.09 ) Weighted-average common shares outstanding: Basic 68,967,875 Diluted 68,967,875

DESCRIPTION OF BUSINESS (Detail

DESCRIPTION OF BUSINESS (Details)	Mar. 09, 2015USD ($)	Mar. 31, 2016USD ($)segmentsales_channelfacilitypropertyproduct	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired (in dollars)		$ 0	$ 697,183,000
Number of reportable segments | segment		2
Number of channels | sales_channel		4
Number of internally developed branded pharmaceutical product candidate | product		1
Number of other branded products | product		4
California
Business Acquisition [Line Items]
Number of owned properties | property		5
Hayward California
Business Acquisition [Line Items]
Number of leased properties | facility		2
Tower And Lineage
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired (in dollars)	$ 691,300,000			$ 691,348,000
Cash acquired from acquisition	$ 41,500,000
Severance costs					$ 2,400,000
Business combination, number of positions eliminated					10

BUSINESS ACQUISITION (Details)

BUSINESS ACQUISITION (Details)	Mar. 09, 2015USD ($)	Sep. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2016USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill				$ 210,166,000	$ 210,166,000	$ 208,382,000
Impax Specialty Pharma
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill						59,700,000
Impax Generics
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill						148,700,000
Tower And Lineage
Acquired Finite-Lived Intangible Assets [Line Items]
Business combination, consideration transferred	$ 691,300,000	$ 697,200,000
Business combination, acquisition related costs			$ 12,000,000	$ 10,900,000
Severance costs					$ 2,400,000
Business combination, number of positions eliminated					10
Restructuring reserve (less than)						100,000
Cash acquired from acquisition	41,500,000
Business combination, acquired receivables, fair value	56,900,000
Business combination, acquired receivables, estimated uncollectible	9,000,000
Business combination, provisional information, initial accounting incomplete, adjustment, consideration transferred		$ 5,900,000
Business combination, cash acquired and other working capital adjustments	41,500,000
Goodwill	180,800,000					$ 180,808,000
Severance and retention costs			3,000,000
Tower And Lineage | Fair Value Adjustment to Inventory
Acquired Finite-Lived Intangible Assets [Line Items]
Assets, fair value adjustment			1,000,000
Tower And Lineage | Term Loan
Acquired Finite-Lived Intangible Assets [Line Items]
Line of credit facility, commitment fee amount			2,300,000
Tower And Lineage | Term Loan | Wells Fargo Bank, N.A.
Acquired Finite-Lived Intangible Assets [Line Items]
Long-term debt			435,000,000
Tower And Lineage | Impax Specialty Pharma
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	59,700,000
Tower And Lineage | Impax Generics
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 121,100,000
General and Administrative Expense | Tower And Lineage
Acquired Finite-Lived Intangible Assets [Line Items]
Business combination, acquisition related costs			$ 5,700,000
Currently marketed product rights
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate	15.00%
In-process research and development product rights
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate	16.00%

BUSINESS ACQUISTION - Fair Valu

BUSINESS ACQUISTION - Fair Values of Tangible and Identifiable Intangible Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 09, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Goodwill		$ 208,382		$ 210,166
Cash paid, net of cash acquired (2)		0	$ 697,183
Tower And Lineage
Restructuring Cost and Reserve [Line Items]
Accounts receivable (1)		56,851
Inventory		31,259
Income tax receivable and other prepaid expenses		2,407
Deferred income taxes		37,041
Property, plant and equipment		27,540
Intangible assets		632,600
Goodwill	$ 180,800	180,808
Other non-current assets		3,844
Total assets assumed		976,350
Current liabilities		67,706
Other non-current liabilities		7,291
Deferred tax liabilities		210,005
Total liabilities assumed		285,002
Cash paid, net of cash acquired (2)	$ 691,300			$ 691,348
Discontinued Operations, Held-for-sale | Tower And Lineage
Restructuring Cost and Reserve [Line Items]
Intangible assets		$ 4,000

BUSINESS ACQUISITIONS - Acquire

BUSINESS ACQUISITIONS - Acquired Intangible Assets (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Amortized intangible assets:
Weighted-Average Estimated Useful Life (years)	10 years 10 months 24 days
Tower And Lineage
Amortized intangible assets:
Estimated Fair Value	$ 632,600
Weighted-Average Estimated Useful Life (years)	12 years
Currently marketed product rights | Tower And Lineage
Amortized intangible assets:
Estimated Fair Value	$ 381,100
Weighted-Average Estimated Useful Life (years)	13 years
Current and future royalty rights | Tower And Lineage
Amortized intangible assets:
Estimated Fair Value	$ 80,800
Weighted-Average Estimated Useful Life (years)	12 years
In-process research and development product rights | Tower And Lineage
Amortized intangible assets:
Estimated Fair Value	$ 170,700

BUSINESS ACQUISITION - The Unau

BUSINESS ACQUISITION - The Unaudited Condensed Pro Forma Consolidated Statements of Operations (Details) - Tower And Lineage $ in Thousands	3 Months Ended
	Mar. 31, 2015USD ($)
Business Acquisition [Line Items]
Total revenues	$ 175,533
Net loss	$ (6,595)

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details)	Mar. 31, 2016
Prohealth Biotech
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	57.54%

SUMMARY OF SIGNIFICANT ACCOUN49

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	May. 02, 2016	Mar. 31, 2016	Mar. 31, 2015	May. 06, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, increase (decrease)		$ (61,960)	$ (21,637)
Accounts receivable, gross, current		729,060			$ 738,730
Accrued liabilities, current		213,112			204,711
Reserve for Turing receivable		$ 48,043	$ 0
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash discount, discount rate		2.00%
Cash discount, invoice terms		30 days
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash discount, discount rate		3.00%
Cash discount, invoice terms		90 days
Turing Pharmaceuticals AG | Subsequent Event
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loss contingency, damages sought, value	$ 20,000
Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net		$ 42,900			$ 40,600
Accounts receivable, increase (decrease)		7,400
Accounts receivable, gross, current		48,000
Accounts receivable, payments made on behalf of counterparty		5,100
Reserve for Turing receivable		48,043
Turing Pharmaceuticals AG | Subsequent Event
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, payments made on behalf of counterparty				$ 19,200
Chargeback and Medical Rebates | Overdue Unpaid Invoices from Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, estimated balance		20,000
Daraprim
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued liabilities, current		$ 42,900

FAIR VALUE MEASUREMENT AND FI50

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Deferred compensation plan assets, carrying amount	$ 30,733	$ 30,726
Liabilities
Deferred compensation plan liabilities, carrying amount	27,766	25,581
2% Convertible senior notes due June 2022
Liabilities
2% convertible senior notes due June 2022, carrying amount	600,000	600,000
2% convertible senior notes due June 2022, fair value	536,472	602,250
Quoted Prices in Active Markets (Level 1)
Assets
Deferred compensation plan assets, carrying amount	0	0
Liabilities
Deferred compensation plan liabilities, carrying amount	0	0
Quoted Prices in Active Markets (Level 1) | 2% Convertible senior notes due June 2022
Liabilities
2% convertible senior notes due June 2022, fair value	536,472	602,250
Significant Other Observable Inputs (Level 2)
Assets
Deferred compensation plan assets, carrying amount	30,733	30,726
Liabilities
Deferred compensation plan liabilities, carrying amount	27,766	25,581
Significant Other Observable Inputs (Level 2) | 2% Convertible senior notes due June 2022
Liabilities
2% convertible senior notes due June 2022, fair value	0	0
Significant Unobservable Inputs (Level 3)
Assets
Deferred compensation plan assets, carrying amount	0	0
Liabilities
Deferred compensation plan liabilities, carrying amount	0	0
Significant Unobservable Inputs (Level 3) | 2% Convertible senior notes due June 2022
Liabilities
2% convertible senior notes due June 2022, fair value	$ 0	$ 0

FAIR VALUE MEASUREMENT AND FI51

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS-PHANTOM (Details)	Mar. 31, 2016	Dec. 31, 2015
Convertible Debt Securities | Quoted Prices in Active Markets (Level 1)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Debt instrument, interest rate, stated percentage	2.00%	2.00%

SHORT-TERM INVESTMENTS (Details

SHORT-TERM INVESTMENTS (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Investments Schedule [Abstract]
Maturities of short-term investments	$ 0	$ 200,064,000
Short-term investments	$ 0		$ 0

ACCOUNTS RECEIVABLE, Compositio

ACCOUNTS RECEIVABLE, Composition of Accounts Receivable Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable (1)	$ 729,060		$ 738,730
Less: Rebate reserve	(320,013)		(265,229)
Less: Chargeback reserve	(104,293)		(102,630)
Less: Distribution services reserve	(11,638)		(12,576)
Less: Discount reserve	(15,469)		(18,657)
Uncollectible Accounts Reserve	63,199		15,187
Reserve for Turing receivable	(48,043)	$ 0
Accounts receivable, net	214,448		324,451
Receivable from Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable (1)	48,000		$ 40,600
Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable (1)	48,000
Reserve for Turing receivable	$ (48,043)

ACCOUNTS RECEIVABLE, Roll Forwa

ACCOUNTS RECEIVABLE, Roll Forward of the Rebate Reserves Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Rebate reserve
Beginning balance	$ 265,229
Ending balance	320,013	$ 265,229
Chargeback Reserve
Rebate reserve
Provision recorded during the period for Impax Generics rebates	223,465	833,157
Credits issued during the period	(221,802)	(798,184)
Rebate Reserve
Rebate reserve
Beginning balance	265,229	88,812
Acquired balances	0	75,447
Provision recorded during the period for Impax Generics rebates	185,476	571,642
Credits issued during the period	(130,692)	(470,672)
Ending balance	$ 320,013	$ 265,229

ACCOUNTS RECEIVABLE, Roll For55

ACCOUNTS RECEIVABLE, Roll Forward of the Chargeback Reserves Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Chargeback reserve
Beginning balance	$ 102,630
Ending balance	104,293	$ 102,630
Chargeback Reserve
Chargeback reserve
Beginning balance	102,630	43,125
Acquired balances	0	24,532
Provision recorded during the period	223,465	833,157
Credits issued during the period	(221,802)	(798,184)
Ending balance	$ 104,293	$ 102,630

INVENTORY, Net of Carrying Valu

INVENTORY, Net of Carrying Value Reserves (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 57,065	$ 52,366
Work in-process	5,935	4,417
Finished goods	89,827	82,311
Total inventory	152,827	139,094
Less: Non-current inventory	19,264	13,512
Total current inventory	$ 133,563	$ 125,582

INVENTORY (Details)

INVENTORY (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Inventory [Line Items]
Inventory valuation reserves	$ 30.9	$ 24.1
Unapproved Inventory
Inventory [Line Items]
Unapproved product inventory, net	$ 5.3	$ 8.7
Raw Materials
Inventory [Line Items]
Inventory turnover period, minimum life	3 years
Inventory turnover period, maximum life	5 years
Finished Goods [Member]
Inventory [Line Items]
Inventory turnover period, maximum life	2 years

PROPERTY, PLANT AND EQUIPMENT,

PROPERTY, PLANT AND EQUIPMENT, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Land	$ 5,603	$ 5,773
Buildings and improvements	169,400	165,322
Equipment	136,599	135,998
Office furniture and equipment	14,975	14,548
Construction in-progress	30,238	25,659
Property, plant and equipment, gross	356,815	347,300
Less: Accumulated depreciation	(137,415)	(133,144)
Property, plant and equipment, net	$ 219,400	$ 214,156

PROPERTY, PLANT AND EQUIPMENT59

PROPERTY, PLANT AND EQUIPMENT, SCHEDULE (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation	$ 6.3	$ 5.4
Property Plant And Equipment Unpaid Vendor Invoices Excluded From Statement Of Cash Flows	$ 4.5	$ 1.3

INTANGIBLE ASSETS AND GOODWILL,

INTANGIBLE ASSETS AND GOODWILL, Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Amortized intangible assets:
Gross Carrying Value	$ 547,176	$ 460,875
Accumulated Amortization	(91,864)	(83,095)
Intangible Assets, Net	455,312	377,780
Non-amortized intangible assets:
Carrying value	141,440	224,240
Total intangible assets, gross	688,616	685,115
Total intangible assets, net	596,752	602,020
Acquired IPR&D product rights
Non-amortized intangible assets:
Carrying value	62,840	145,640
Acquired future royalty rights
Non-amortized intangible assets:
Carrying value	78,600	78,600
Marketed product rights
Amortized intangible assets:
Gross Carrying Value	544,976	458,675
Accumulated Amortization	(91,618)	(82,906)
Intangible Assets, Net	453,358	375,769
Royalties
Amortized intangible assets:
Gross Carrying Value	2,200	2,200
Accumulated Amortization	(246)	(189)
Intangible Assets, Net	$ 1,954	$ 2,011

INTANGIBLE ASSETS AND GOODWIL61

INTANGIBLE ASSETS AND GOODWILL (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Amortized intangible assets:
Acquired finite-lived intangible assets, weighted average useful life	10 years 10 months 24 days
Gross Carrying Value	$ 547,176		$ 460,875
Carrying value	141,440		224,240
Amortization of Intangible Assets	8,800	$ 4,300
Goodwill	208,382		210,166
Minimum
Expected Amortization Expense
2,016	37,800
2,017	37,800
2,018	37,800
2,019	37,800
2,020	37,800
Maximum
Expected Amortization Expense
2,016	59,100
2,017	59,100
2,018	59,100
2,019	59,100
2,020	59,100
Impax Generics
Amortized intangible assets:
Goodwill	148,700
Impax Specialty Pharma
Amortized intangible assets:
Goodwill	59,700
Teva
Amortized intangible assets:
Milestone payment, capitalized	3,500
Marketed Product Rights
Amortized intangible assets:
Gross Carrying Value	544,976		458,675
Marketed Product Rights | EMVERM
Amortized intangible assets:
Gross Carrying Value	$ 86,300
In-process research and development
Amortized intangible assets:
Indefinite-lived Intangible Assets (Excluding Goodwill), Fair Value Disclosure			82,800
In-process research and development | EMVERM
Amortized intangible assets:
Carrying value			$ 82,800

ACCRUED EXPENSES (Details)

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payroll-related expenses	$ 23,500	$ 37,419
Product returns	56,044	48,950
Accrued shelf stock	9,995	6,619
Government rebates (1)	99,606	91,717
Legal and professional fees	8,965	5,929
Income taxes payable	2,558	830
Physician detailing sales force fees	327	1,132
Interest payable	3,500	500
Other	8,617	11,615
Total accrued expenses	213,112	204,711
Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	42,900	$ 40,600
Accounts receivable, payments made on behalf of counterparty	$ 5,100

ACCRUED EXPENSES, Product Retur

ACCRUED EXPENSES, Product Returns (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 48,950
Ending balance	56,044	$ 48,950
Returns Reserve
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	48,950	27,174
Acquired balances	0	11,364
Provision related to sales recorded in the period	13,421	43,967
Credits issued during the period	(6,327)	(33,555)
Ending balance	$ 56,044	$ 48,950

DEBT (Details)

DEBT (Details)	Aug. 04, 2015USD ($)	Jun. 30, 2015USD ($)$ / shares	Mar. 31, 2016USD ($)day$ / shares	Jun. 30, 2015USD ($)$ / shares	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)	Mar. 09, 2015USD ($)
Debt Instrument [Line Items]
Proceeds from Convertible Debt		$ 436,400,000		$ 600,000,000
Convertible Debt, Noncurrent			$ 429,900,000			$ 424,600,000
Cash paid for interest			$ 7,000		$ 2,317,000
Conversion Option
Debt Instrument [Line Items]
Derivative Liability, Fair Value, Gross Liability		167,000,000		167,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Percentage to Increase or Decrease Applicable Margin	0.75%
Barclays Senior Credit Facilities
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		17,800,000		$ 17,800,000
Barclays Senior Credit Facilities | Revolver
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 50,000,000
Barclays Senior Credit Facilities | Term Loan
Debt Instrument [Line Items]
Interest Expense, Debt					4,000,000
Accretion Expense					200,000
Long-term debt							$ 435,000,000
Repayments of Long-term Debt		435,000,000
Cash paid for interest		1,400,000			3,800,000
Gains (Losses) on Extinguishment of Debt		$ 16,900,000
Debt Instrument, Fee Amount					$ 2,300,000
Convertible Debt
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		2.00%	2.00%	2.00%
Conversion of Stock, Conversion Ratio			15.7858	0.0157858
Debt Instrument, Convertible, Conversion Price (in Dollars per share) | $ / shares		$ 63.35	$ 63.35	$ 63.35
Debt Instrument, Convertible, Threshold Trading Days | day			20
Debt Instrument, Convertible, Threshold Consecutive Trading Days			30 days
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger			130.00%
Debt Issuance Cost		$ 18,700,000		$ 18,700,000
Interest Expense, Debt			$ 8,300,000
Debt Instrument, Increase, Accrued Interest			3,000,000
Accretion Expense			5,300,000
Interest Payable			$ 3,500,000			$ 500,000
Convertible Debt | Conversion Circumstance 2
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days | day			5
Debt Instrument, Convertible, Threshold Consecutive Trading Days			10 days
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger			98.00%

STOCKHOLDERS' EQUITY (Details)

STOCKHOLDERS' EQUITY (Details) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2016USD ($)shares$ / shares	Jun. 30, 2015$ / shares	Dec. 31, 2015USD ($)$ / sharesshares
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	2,000,000		2,000,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share) | $ / shares	$ 0.01		$ 0.01
Preferred stock, shares issued	0		0
Preferred Stock, Shares Outstanding	0		0
Common stock, shares authorized	150,000,000		150,000,000
Common Stock, Par or Stated Value Per Share (in Dollars per share) | $ / shares	$ 0.01		$ 0.01
Common Stock, Shares, Issued	73,339,655		72,926,205
Common stock, shares outstanding	73,095,926		72,682,476
Warrant
Class of Stock [Line Items]
Debt Conversion, Converted Instrument, Warrants or Options Issued	9,471,000
Proceeds from Warrant Exercises (in Dollars) | $	$ 88.3
Investment Warrants, Exercise Price (in Dollars per share) | $ / shares	$ 81.277
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt | $			$ 21
Convertible Debt
Class of Stock [Line Items]
Debt Instrument, Convertible, Number of Equity Instruments	600,000
Payments for Hedge, Financing Activities | $	$ 147
Conversion of Stock, Conversion Ratio	15.7858	0.0157858
Debt Instrument, Convertible, Conversion Price (in Dollars per share) | $ / shares	$ 63.35	$ 63.35

STOCKHOLDERS' EQUITY, Common St

STOCKHOLDERS' EQUITY, Common Stock Reserved for Future Issuance (Details) - shares	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Shares issued	73,339,655	72,926,205
Total shares of common stock issued and reserved for issuance	94,762,000
Warrant
Class of Stock [Line Items]
Common shares reserved for issuance	9,471,000
Employee Stock Option
Class of Stock [Line Items]
Common shares reserved for issuance	2,480,000
Warrant
Class of Stock [Line Items]
Conversion of Notes payable	9,471,000

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	9,470
Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	9,470
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,480	3,160
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,150	2,480

EARNINGS PER SHARE, Reconciliat

EARNINGS PER SHARE, Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net loss	$ (10,408)	$ (6,333)
Weighted-average common shares outstanding	70,665,394	68,967,875
Basic loss per share (in Dollars per share)	$ (0.15)	$ (0.09)
Add-back of interest expense on outstanding convertible notes payable, net of tax	$ 0	$ 0
Adjusted net loss	$ (10,408)	$ (6,333)
Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance	0	0
Weighted-average incremental shares assuming conversion of outstanding notes payable	0	0
Diluted weighted-average common shares outstanding	70,665,394	68,967,875
Diluted net income (loss) per share (in Dollars per share)	$ (0.15)	$ (0.09)

SHARE-BASED COMPENSATION (Detai

SHARE-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Oct. 31, 2000
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,480,187		2,405,371
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	7 years 8 months 16 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 6 months 29 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 26.1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 22.3
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number (in Shares)	2,195,692
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)	1,405,039
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized (in Dollars)	$ 65.5
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 1 month 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value (in Dollars)	$ 4	$ 4.2
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
Stock Options And Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Stock Options And Restricted Stock Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Stock Options And Restricted Stock Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding	$ 68.9
Share Based Compensation Arrangement by Share-based Payment Award Equity Instruments Other Than Options Vested and Expected to Vest Outstanding, Number (in Shares)	1,906,109
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	72,690
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value (in Dollars)	$ 2.6	$ 0.6
The 1999 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized				5,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	938		10,938
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)	296,921
Amended and Restated 2002 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	14,950,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,479,249		2,394,433
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	2,153,083		2,146,498
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)	1,036,675
The ESPP Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)	71,443
Withheld for Minimum Withholding Tax Purposes | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	27,206
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 36.89

SHARE-BASED COMPENSATION, Summa

SHARE-BASED COMPENSATION, Summary of Stock Option Activity (Details) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2016
Number of Shares Under Option
Outstanding at December 31, 2015	2,405,371
Options granted	426,390
Options exercised	(351,574)
Options forfeited	0
Outstanding at March 31, 2016	2,480,187
Options exercisable at March 31, 2016		1,376,812
Weighted- Average Exercise Price per Share
Outstanding at December 31, 2015	$ 21.39
Options granted	13.10
Options exercised	20.95
Options forfeited	0
Outstanding at March 31, 2016	$ 21.39	$ 23.50
Options exercisable at March 31, 2016		$ 16.35

SHARE-BASED COMPENSATION, Sum71

SHARE-BASED COMPENSATION, Summary of Non-vested Restricted Stock Awards (Details) - Restricted Stock Awards	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Number of Restricted Stock Awards
Non-vested at December 31, 2015 | shares	2,146,498
Granted | shares	186,264
Vested | shares	(72,690)
Forfeited | shares	(106,989)
Non-vested at March 31, 2016 | shares	2,153,083
Weighted- Average Grant Date Fair Value
Non-vested at December 31, 2015 | $ / shares	$ 33.20
Granted | $ / shares	33.42
Vested | $ / shares	35.67
Forfeited | $ / shares	32.49
Non-vested at March 31, 2016 | $ / shares	$ 33.17

SHARE-BASED COMPENSATION, Share

SHARE-BASED COMPENSATION, Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 7,278	$ 6,488
Manufacturing Expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	1,368	1,046
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	1,340	1,365
Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 4,570	$ 4,077

RESTRUCTURINGS (Details)

RESTRUCTURINGS (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)position	Dec. 31, 2015USD ($)position	Jun. 30, 2015USD ($)position
Cost of Sales
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 1.4
Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Estimated Completion Period	2 years
Restructuring and Related Cost, Expected Number of Positions Eliminated | position	215
Technical Operations and R&D
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated | position		27
Severance costs (in Dollars)		$ 2.5
Payments for Restructuring (in Dollars)	$ 1.1
Packaging and Distribution Operations
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated | position			93
Restructuring and Related Cost, Incurred Cost			$ 2.6
Payments for Restructuring (in Dollars)	1.6
Asset Impairment and Accelerated Depreciation
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Accelerated Depreciation	0.6
Legal and Professional Fees [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.1
Employee Retention and Termination
Restructuring Cost and Reserve [Line Items]
Severance costs (in Dollars)	0.7
Asset Retirement Obligation Costs | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	2
Minimum | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Aggregate Pre-Tax Charges Estimated Next Two Fiscal Years, Amount	45
Restructuring and Related Cost, Expected Cost	45
Minimum | Product Transfer | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	12
Minimum | Asset Impairment and Accelerated Depreciation | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	19
Minimum | Employee Retention and Termination | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	12
Maximum | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Aggregate Pre-Tax Charges Estimated Next Two Fiscal Years, Amount	53
Restructuring and Related Cost, Expected Cost	53
Maximum | Product Transfer | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	14
Maximum | Asset Impairment and Accelerated Depreciation | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	23
Maximum | Employee Retention and Termination | Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 14

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (benefit) for income taxes	$ 7,086	$ 4,372
Effective income tax rate reconciliation, excluding discrete items, percent	34.00%
Effective income tax rate reconciliation, percent	41.00%	41.00%
Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (benefit) for income taxes	$ 17,400

ALLIANCE AND COLLABORATION AG75

ALLIANCE AND COLLABORATION AGREEMENTS (Details)

1 Months Ended

3 Months Ended

12 Months Ended

25 Months Ended

Apr. 30, 2013USD ($)

Jun. 30, 2012product

Jun. 30, 2010USD ($)

Dec. 31, 2009USD ($)

Sep. 30, 2009USD ($)

Mar. 31, 2009USD ($)

Dec. 31, 2008USD ($)

Jun. 30, 2002

Mar. 31, 2016USD ($)product

Jun. 30, 2015USD ($)

Mar. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Mar. 31, 2014USD ($)

Dec. 31, 2013USD ($)

Mar. 31, 2013USD ($)

Dec. 31, 2013USD ($)

Dec. 31, 2012USD ($)

Dec. 31, 2011product

Dec. 31, 2009payment

Mar. 31, 2011USD ($)

Dec. 31, 2010USD ($)

Dec. 31, 2015USD ($)

Mar. 31, 2012USD ($)

Jan. 31, 2012

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Accrued profit sharing and royalty expenses

$ 38,709,000

$ 65,725,000

Research and Development Expense

19,022,000

$ 14,962,000

Teva

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Milestone Payment, Paid

3,500,000

Tolmar Incorporated

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Maximum Loan Amount Pursuant to Loan and Security Agreement

$ 15,000,000

15,000,000

$ 15,000,000

Acceptance Of Regulatory Filings For Substantive Review

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

2 months

Minimum | IND-enabling Animal Studies for New Development Candidate

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

12 months

Minimum | Phase 1 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

1 year

Minimum | Phase 2 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

1 year

Minimum | Phase 3 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

2 years

Minimum | Bioequivalence Studies

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

3 months

Minimum | Preparation And Submission Of Regulatory Filings

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

6 months

Minimum | Potential Marketing Approval One

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

1 year

Minimum | Potential Marketing Approval Two

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

1 year

Minimum | Tolmar Product Rights

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Finite-Lived Intangible Asset, Useful Life

5 years

Maximum | IND-enabling Animal Studies for New Development Candidate

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

18 months

Maximum | Phase 1 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

2 years

Maximum | Phase 2 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

3 years

Maximum | Phase 3 Trials

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

4 years

Maximum | Bioequivalence Studies

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

1 year

Maximum | Preparation And Submission Of Regulatory Filings

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

12 months

Maximum | Potential Marketing Approval One

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

3 years

Maximum | Potential Marketing Approval Two

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Completion Period

3 years

Maximum | Tolmar Product Rights

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Finite-Lived Intangible Asset, Useful Life

12 years

Specified Threshold

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Product Sales

$ 100,000,000

Shire Laboratories Incorporated

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Accrued profit sharing and royalty expenses

4,000,000

5,800,000

Tolmar Incorporated

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Accrued profit sharing and royalty expenses

$ 24,700,000

7,500,000

Number Of Products | product

11

Collaborative Arrangement Up Front Payment

$ 21,000,000

Tolmar Incorporated | Products Approved

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | product

10

Tolmar Incorporated | Products in Development

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | payment

2

Research and Development Expense

1,550,000

Tolmar Incorporated | Up-front Payment Arrangement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Up Front Payment

21,000,000

Tolmar Incorporated | Milestone Payments

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Required Payment Net

$ 5,000,000

$ 12,000,000

1,000,000

Research and Development Expense

1,000,000

Tolmar Incorporated | Milestone Payments | Diclofenac Sodium Gel

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Required Payment Net

$ 2,000,000

Teva Pharmaceutical Industries Limited

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Service Agreement Term

10 years

Pfizer Incorporated

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Service Agreement Term

15 years

Valeant Pharmaceuticals International

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | product

5

Valeant Pharmaceuticals International | Products Approved

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | product

1

Valeant Pharmaceuticals International | Generic Products

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | product

4

4

Valeant Pharmaceuticals International | Branded Advanced Form of Solodyn Product

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Number Of Products | product

1

Valeant Pharmaceuticals International | Up-front Payment Arrangement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Contingent Payments Received And Potentially To Be Received

$ 40,000,000

Valeant Pharmaceuticals International | Milestone Payments

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Contingent Payments Received And Potentially To Be Received

$ 2,000,000

$ 5,000,000

$ 5,000,000

$ 3,000,000

Collaborative Arrangement Maximum Contingent Payments Amount

$ 8,000,000

Valeant Pharmaceuticals International | Milestone Payment Arrangement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Contingent Payments Received And Potentially To Be Received

$ 15,000,000

$ 12,000,000

Endo Pharmaceuticals Incorporation

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Gain (Loss) Related to Litigation Settlement

$ 102,049,000

Deferred Revenue Estimated Period Of Recognition

112 months

Litigation Settlement, Amount

$ 102,049,000

Endo Pharmaceuticals Incorporation | Up-front Payment Arrangement

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Deferred Revenue, Additions

$ 10,000,000

Deferred Revenue

$ 0

$ 0

Endo Pharmaceuticals Incorporation | Milestone Payments

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Maximum Contingent Payments Amount

30,000,000

Astra Zeneca

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Quarterly Payments Made

$ 43,564,000

Collaborative Arrangement Copromotion Service Fee Percentage

100.00%

Accrued Royalties

4,019,000

$ 4,025,000

DURECT Corporation

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaborative Arrangement Up Front Payment

$ 2,000,000

Collaborative Arrangement Maximum Contingent Payments Amount

$ 61,000,000

Other Income | Shire Laboratories Incorporated

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Gain (Loss) Related to Litigation Settlement

$ 48,000,000

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase Commitment, Remaining Minimum Amount Committed	$ 66.1
Purchase Commitment Period (less than)	1 year
Contractual Obligation	$ 1.8

LEGAL AND REGULATORY MATTERS (D

LEGAL AND REGULATORY MATTERS (Details) $ in Millions	May. 02, 2016USD ($)	Mar. 31, 2016complaint	Feb. 29, 2016complaint	Jan. 31, 2016complaint
Loss Contingencies [Line Items]
Loss Contingency Patent Infringement Period Within Which Patent Holder May File Suit for Patent Infringement (in days)		45 days
Loss Contingency Patent Infringement Litigation Maximum Stay Period For Approval Of Abbreviated New Drug Application		30 months
Solodyn
Loss Contingencies [Line Items]
Number of Class Action Complaints				18
Opana ER
Loss Contingencies [Line Items]
Number of Class Action Complaints			14
Generic Drug Pricing Class Action
Loss Contingencies [Line Items]
Number of Class Action Complaints		8
Subsequent Event | Turing Pharmaceuticals AG
Loss Contingencies [Line Items]
Chargebacks not reimbursed for (more than) | $	$ 20

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)segmentproduct	Dec. 31, 2015USD ($)
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of reportable segments | segment	2
Number of internally developed branded pharmaceutical product candidate | product	1
Number of products sold and distributed | product	4
Assets | $	$ 1,886,299	$ 1,922,487
Taiwan Facility
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets | $	$ 134,700	$ 131,600

SEGMENT INFORMATION, Segment In

SEGMENT INFORMATION, Segment Information Reconciled to Consolidated Financial Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 225,508	$ 143,096
Cost of revenues	122,918	83,862
Selling, general and administrative	44,298	50,160
Research and development	19,022	14,962
Patent litigation	1,319	960
Income (loss) before income taxes	(17,494)	(10,705)
Corporate and Other
Segment Reporting Information [Line Items]
Selling, general and administrative	25,706	31,018
Income (loss) before income taxes	(81,151)	(34,875)
Impax Generics
Segment Reporting Information [Line Items]
Total revenues	170,079	128,741
Impax Generics | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	170,079	128,741
Cost of revenues	110,122	76,472
Selling, general and administrative	4,774	4,286
Research and development	14,595	10,863
Patent litigation	114	778
Income (loss) before income taxes	40,474	36,342
Impax Specialty Pharma
Segment Reporting Information [Line Items]
Total revenues	55,429	14,355
Impax Specialty Pharma | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	55,429	14,355
Cost of revenues	12,796	7,390
Selling, general and administrative	13,818	14,856
Research and development	4,427	4,099
Patent litigation	1,205	182
Income (loss) before income taxes	$ 23,183	$ (12,172)

SUPPLEMENTARY FINANCIAL INFOR80

SUPPLEMENTARY FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Less:
Total revenues	$ 225,508	$ 143,096
Gross profit	102,590	59,234
Net loss	$ (10,408)	$ (6,333)
Net loss per common share:
Basic (in Dollars per share)	$ (0.15)	$ (0.09)
Diluted (in Dollars per share)	$ (0.15)	$ (0.09)
Weighted-average common shares outstanding:
Basic (in Shares)	70,665,394	68,967,875
Diluted (in Shares)	70,665,394	68,967,875
Impax Generics
Revenue:
Impax sales, gross	$ 611,281	$ 355,321
Less:
Product Returns	11,913	6,427
Impax product sales, net	167,184	125,959
Total revenues	170,079	128,741
Impax Specialty Pharma
Revenue:
Impax sales, gross	82,073	29,219
Less:
Product Returns	1,508	2,620
Impax product sales, net	55,429	14,128
Total revenues	55,429	14,355
Rx Partner | Impax Generics
Less:
Other Revenues	2,835	2,239
Other Revenues | Impax Generics
Less:
Other Revenues	60	543
Other Revenues | Impax Specialty Pharma
Less:
Other Revenues	0	227
Chargeback Reserve
Less:
Sales Allowances	223,465		$ 833,157
Chargeback Reserve | Impax Generics
Less:
Sales Allowances	217,354	126,607
Chargeback Reserve | Impax Specialty Pharma
Less:
Sales Allowances	6,111	5,561
Rebate Reserve
Less:
Sales Allowances	185,476		$ 571,642
Rebate Reserve | Impax Generics
Less:
Sales Allowances	185,476	83,130
Rebate Reserve | Impax Specialty Pharma
Less:
Sales Allowances	2,853	2,132
Other Credits | Impax Generics
Less:
Sales Allowances	29,354	13,198
Other Credits | Impax Specialty Pharma
Less:
Sales Allowances	$ 16,172	$ 4,778