Impax Laboratories (IPXL) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - shares	3 Months Ended
	Mar. 31, 2018	May 03, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Impax Laboratories, LLC
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, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		73,758,396
Entity Current Reporting Status	Yes

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 104,192	$ 181,778
Accounts receivable, net	226,373	240,753
Inventory, net	158,591	158,471
Prepaid expenses and other current assets	20,211	21,086
Income tax receivable	68,294	61,201
Assets held for sale	0	32,266
Total current assets	577,661	695,555
Property, plant and equipment, net	123,288	124,813
Intangible assets, net	248,994	262,467
Goodwill	207,329	207,329
Other non-current assets	63,626	61,136
Total assets	1,220,898	1,351,300
Current liabilities:
Accounts payable	65,261	81,093
Accrued expenses	268,676	248,127
Liabilities held for sale	0	7,170
Current portion of long-term debt, net	17,859	17,848
Total current liabilities	351,796	354,238
Long-term debt, net	771,216	769,524
Deferred income taxes	660	3,226
Other non-current liabilities	37,623	37,111
Total liabilities	1,161,295	1,164,099
Commitments and contingencies (Notes 17 & 18)
Stockholders’ equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; No shares issued or outstanding at March 31, 2018 and December 31, 2017	0	0
Common stock, $0.01 par value, 150,000,000 shares authorized; 74,080,636 issued and 73,836,907 outstanding shares at March 31, 2018; 74,234,076 issued and 73,990,347 outstanding shares at December 31, 2017	741	742
Treasury stock at cost: 243,729 shares at March 31, 2018 and December 31, 2017	(2,157)	(2,157)
Additional paid-in capital	563,974	559,632
Accumulated deficit	(503,004)	(372,445)
Accumulated other comprehensive income	49	1,429
Total stockholders’ equity	59,603	187,201
Total liabilities and stockholders’ equity	$ 1,220,898	$ 1,351,300

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	74,080,636	74,234,076
Common stock, shares outstanding (in shares)	73,836,907	73,990,347
Treasury stock at cost, shares (in shares)	243,729	243,729

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Total revenues	$ 142,355	$ 184,403
Cost of revenues	112,075	120,232
Cost of revenues impairment charges	0	39,280
Gross profit	30,280	24,891
Operating expenses:
Selling, general and administrative	57,323	47,055
Research and development	12,296	22,489
In-process research and development impairment charges	0	6,079
Litigation, settlements and related charges	85,537	1,072
Total operating expenses	155,156	76,695
Loss from operations	(124,876)	(51,804)
Other income (expense):
Interest expense, net	(13,692)	(13,226)
Loss on sale of assets	(385)	0
Loss on debt extinguishment	0	(1,215)
Other, net	731	(1,285)
Loss before income taxes	(138,222)	(67,530)
(Benefit from) provision for income taxes	(7,290)	30,901
Net loss	$ (130,932)	$ (98,431)
Net loss per common share:
Basic (in dollars per share)	$ (1.81)	$ (1.37)
Diluted (in dollars per share)	$ (1.81)	$ (1.37)
Weighted-average common shares outstanding:
Basic (in shares)	72,265,794	71,594,472
Diluted (in shares)	72,265,794	71,594,472
Impax Generics, net
Revenues:
Total revenues	$ 83,141	$ 134,147
Impax Specialty Pharma, net
Revenues:
Total revenues	$ 59,214	$ 50,256

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (130,932)	$ (98,431)
Other comprehensive loss, net of tax:
Change in foreign currency translation adjustments	(531)	8,655
Foreign currency translation adjustments reclassified to other non-operating income	(849)	0
Other comprehensive (loss) income	(1,380)	8,655
Comprehensive loss	$ (132,312)	$ (89,776)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (130,932,000)	$ (98,431,000)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	17,977,000	25,751,000
Non-cash interest expense	6,763,000	6,312,000
Share-based compensation expense	4,816,000	6,957,000
Deferred income taxes, net and uncertain tax positions	(2,591,000)	32,195,000
Intangible asset impairment charges	0	45,359,000
Loss on sale of assets	385,000	0
Loss on debt extinguishment	0	1,215,000
Other	53,000	(245,000)
Changes in certain assets and liabilities:
Accounts receivable	14,754,000	43,033,000
Inventory	2,460,000	(19,153,000)
Prepaid expenses and other assets	(8,513,000)	(6,525,000)
Accounts payable and accrued expenses	8,811,000	806,000
Other liabilities	537,000	2,531,000
Net cash (used in) provided by operating activities	(85,480,000)	39,805,000
Cash flows from investing activities:
Purchases of property, plant and equipment	(3,958,000)	(8,679,000)
Proceeds from cash surrender value of life insurance policy	0	529,000
Proceeds from sale of assets	17,755,000	0
Net cash provided by (used in) investing activities	13,797,000	(8,150,000)
Cash flows from financing activities:
Repayment of term loan	(5,000,000)	(55,000,000)
Payment of deferred financing fees	0	(818,000)
Payment of withholding taxes related to restricted stock awards	(982,000)	(448,000)
Proceeds from exercises of stock options and ESPP	505,000	170,000
Net cash used in financing activities	(5,477,000)	(56,096,000)
Effect of exchange rate changes on cash and cash equivalents	(426,000)	1,560,000
Net decrease in cash and cash equivalents	(77,586,000)	(22,881,000)
Cash and cash equivalents, beginning of period	181,778,000	180,133,000
Cash and cash equivalents, end of period	104,192,000	157,252,000
Supplemental disclosure of cash flow information:
Cash paid for interest	4,393,000	3,871,000
Cash paid for income taxes	$ 2,329,000	$ 3,500,000

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION Impax Laboratories, LLC (“Impax” or the “Company”), formerly known as Impax Laboratories, Inc., 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 Company owns and/or leases facilities in California, Pennsylvania, and New Jersey. In California, the Company utilizes a combination of owned and leased facilities mainly located in Hayward for manufacturing and research and development. The Company’s facilities in Pennsylvania and New Jersey are primarily marketing, finance and administrative. Effective on May 4, 2018, the Company completed its previously announced business combination with Amneal Pharmaceuticals LLC (“Amneal”) pursuant to the Business Combination Agreement dated October 17, 2017, as amended on November 21, 2017 and December 16, 2017 (the “BCA”) with Atlas Holdings, Inc., (now Amneal Pharmaceuticals, Inc., as described below) a Delaware corporation and a then wholly-owned subsidiary of the Company (“Holdco”), K2 Merger Sub Corporation, a Delaware corporation and a then wholly-owned subsidiary of Holdco (“Merger Sub”), and Amneal. The BCA was unanimously approved by the board of directors of the Company on October 16, 2017 and approved by the Company's shareholders on March 27, 2018. At the closing of the transactions contemplated by the BCA on May 4, 2018, (i) Merger Sub merged with and into the Company (the “Impax Merger”), with the Company surviving the Impax Merger as a direct wholly-owned subsidiary of Holdco, (ii) each share of the Company’s common stock, par value $0.01 per share (“Company Common Stock”), issued and outstanding immediately prior to the Impax Merger, other than Company Common Stock held by the Company in treasury, by Amneal or by any of their respective subsidiaries, was converted into the right to receive one fully paid and nonassessable share of Class A common stock of Holdco, par value $0.01 per share (“Holdco Class A Common Stock”), (iii) the Company converted to a limited liability company pursuant to the General Corporation Law of the State of Delaware and the Delaware Limited Liability Company Act, (iv) Holdco contributed to Amneal all of Holdco’s equity interests in the Company to Amneal, in exchange for common units of Amneal (the “Contribution”), (v) Holdco issued an aggregate number of shares of Class B common stock of Holdco, par value $0.01 per share (“Holdco Class B Common Stock”, and together with Holdco Class A Common Stock, “Holdco Common Stock”) to the existing members of Amneal (the “Amneal Members”) and (vi) Holdco became the managing member of Amneal. In connection with the Closing, Holdco was renamed Amneal Pharmaceuticals, Inc. (“New Amneal”). Immediately following the Closing, (i) the Amneal Members held 100% of Holdco Class B Common Stock, which, together with their common units of Amneal, represented approximately 75% of the voting power and economic interests in New Amneal, and (ii) the Company’s stockholders immediately prior to the Closing held 100% of the Holdco Class A Common Stock, which represented approximately 25% of the voting power and economic interests in New Amneal. The accompanying unaudited interim consolidated financial statements have been prepared from the books and records of Impax Laboratories, Inc., the legal entity that existed as of March 31, 2018 prior to the conversion to a limited liability company ("LLC") noted above, in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and Rule 10-01 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, 2017, as filed with the SEC, wherein a more complete discussion of significant accounting policies and certain other information can be found.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Recently Adopted Accounting Guidance In May 2014, the Financial Accounting Standards Board ("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 provided 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 is effective for annual and interim periods beginning after December 15, 2017. In April 2016 and May 2016, the FASB issued ASU 2016-10, " Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing " and ASU 2016-12, " Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ," respectively. Both of these updates provide improvements and clarification to the previously issued revenue recognition guidance. The new standard can be adopted using one of two methods: the full retrospective method, which requires the standard to be applied to each prior period presented, or the modified retrospective method, which requires the cumulative effect of adoption to be recognized as an adjustment to opening retained earnings in the period of adoption. Under Topic 606, the Company will recognize revenue earlier on certain of its less significant transactions involving third-party collaborations and other arrangements. The Company adopted the new guidance effective January 1, 2018 using the modified retrospective transition method, which resulted in a $0.4 million charge to opening retained earnings for 2018 which otherwise would have been recognized as revenue in the three months ended March 31, 2018. There was no effect to total revenues for the three months ended March 31, 2018 as a result of adopting the new accounting on January 1, 2018. The amounts as reported in these unaudited consolidated financial statements were the same as the amounts would have been if the previous accounting guidance was in effect. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): " Classification of Certain Cash Receipts and Cash Payments, " with guidance intended to reduce the diversity in practice regarding how certain cash receipts and cash payments are presented and classified within the statement of cash flows. The update addresses eight specific cash flow issues including debt prepayment or debt extinguishment costs, the settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)), distributions received from equity method investees, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In October 2016, the FASB issued ASU-2016-16, Income Taxes (Topic 740): " Intra-Entity Transfers of Assets Other Than Inventory, " with guidance intended to more faithfully represent the economics of intra-entity asset transfers. The update clarifies that entities must recognize the income tax consequences of intra-entity asset transfers, other than inventory, when the transfer occurs. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU-2017-01, Business Combinations (Topic 805): "Clarifying the Definition of a Business," with guidance intended to assist entities in evaluating whether transactions should be accounted for as acquisitions (or disposals) of businesses. The update provides a screen to determine whether an integrated set of assets and activities constitute a business. If the screen is not met, the guidance (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) removes the evaluation of whether a market participant could replace the missing elements. The guidance is effective for annual and interim periods beginning after December 15, 2017 and will be applied prospectively. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): "Scope of Modification Accounting," which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The guidance is effective for annual and interim periods beginning after December 15, 2017. The amendments in this ASU are applied prospectively to an award modified on or after the adoption date. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. Accounting Guidance Issued Not Yet Adopted 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 will have on its consolidated financial statements and related disclosures. The Company's expects the implementation of this standard to have an impact on its consolidated financial statements and related disclosures as it has aggregate future minimum lease payments of $28.1 million as of December 31, 2017 under the current portfolio of non-cancelable leases for land, office space, and manufacturing, warehouse and research and development facilities with various expiration dates between January 2018 and December 2027. The Company anticipates recognition of additional assets and corresponding liabilities related to these leases on its consolidated balance sheet.

REVENUE RECOGNITION

REVENUE RECOGNITION	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION The Company adopted Accounting Standards Codification 606, Revenue from Contracts with Customers (“Topic 606”), as of January 1, 2018 using the modified retrospective transition method. Topic 606 prescribes a five step model for recognizing revenue which includes (i) identifying contracts with customers; (ii) identifying performance obligations; (iii) determining the transaction price; (iv) allocating the transaction price and (v) recognizing revenue. Product Revenue, 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 product revenues may include deductions from the gross sales price related to estimates for chargebacks, rebates and administrative fees, distribution service fees, returns, shelf-stock adjustments, and other pricing adjustments. The Company records an estimate for these deductions as variable consideration 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 retail pharmacy chains, group purchasing organizations, 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 and Administrative Fees - The Company maintains various rebate and administrative fee 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 for credit expired product under the terms of its published Returns Goods Policy. 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. Profit share and other revenues The Company has entered into agreements, where it licenses certain rights to its products to customers. For arrangements that include sales-based royalties, the Company recognizes revenue when the related sales occur.

FAIR VALUE MEASUREMENT AND FINA

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2018
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, 2018 and December 31, 2017 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, 2018 and December 31, 2017 are indicated below (in thousands): As of March 31, 2018 Fair Value Measurement Based on Carrying Fair Value Quoted Prices in Active Markets Significant Significant Unobservable Assets Deferred Compensation Plan asset (1) $ 42,594 $ 42,594 $ — $ 42,594 $ — Liabilities Term Loan Facility due August 2021, current portion (2) $ 20,000 $ 20,000 $ — $ 20,000 $ — Term Loan Facility due August 2021, long-term portion (2) $ 300,000 $ 300,000 $ — $ 300,000 $ — 2% Convertible Senior Notes due June 2022 (3) $ 600,000 $ 597,000 $ 597,000 $ — $ — Deferred Compensation Plan liabilities (1) $ 33,899 $ 33,899 $ — $ 33,899 $ — Contingent consideration (4) $ — $ — $ — $ — $ — As of December 31, 2017 Fair Value Measurement Based on Carrying Fair Value Quoted Prices in Active Markets Significant Significant Unobservable Assets Deferred Compensation Plan asset (1) $ 43,023 $ 43,023 $ — $ 43,023 $ — Liabilities Term Loan Facility due August 2021, current portion (2) $ 20,000 $ 20,000 $ — $ 20,000 $ — Term Loan Facility due August 2021, long-term portion (2) $ 305,000 $ 305,000 $ — $ 305,000 $ — 2% Convertible Senior Notes due June 2022 (3) $ 600,000 $ 579,378 $ 579,378 $ — $ — Deferred Compensation Plan liabilities (1) $ 33,413 $ 33,413 $ — $ 33,413 $ — Contingent consideration (4) $ — $ — $ — $ — $ — (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 policies (COLIs), 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, 2018 and December 31, 2017 represents the unaccreted discount related to deferred debt issuance costs. (3) 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, 2018 and December 31, 2017 represents the unaccreted discounts related to deferred debt issuance costs and bifurcation of the conversion feature of the notes. (4) Under the terms of the Termination Agreement which was effective August 3, 2016 and was executed as part of our acquisition of certain assets from Teva Pharmaceuticals USA, Inc. and Allergan plc, the ("Teva Transaction"). the Company could be contractually obligated to make payments up to $40.0 million based on the achievement of certain commercial and time-based milestones associated with is methylphenidate hydrochloride product. A discounted cash flow calculation model was used to value the contingent consideration using significant unobservable inputs, including the probability and timing of successful product launch, the expected number of product competitors in the market at the time of launch (as defined in the Termination Agreement) and the expected number of such competitors in the market o the one-year launch anniversary date. The Company conducted a review of the underlying inputs and assumptions at March 31, 2018 and December 31, 2017, and based on timing and probability of the product launch, and corresponding number of competitors expected to be in the market at both launch and the one-year anniversary of launch, the Company concluded that the fair value of its contingent consideration was zero .

ACCOUNTS RECEIVABLE

ACCOUNTS RECEIVABLE	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
ACCOUNTS RECEIVABLE	ACCOUNTS RECEIVABLE The composition of accounts receivable, net is as follows (in thousands): March 31, 2018 December 31, 2017 Gross accounts receivable (1) $ 512,113 $ 634,059 Less: Rebate reserve (112,019 ) (181,611 ) Less: Chargeback reserve (100,516 ) (136,891 ) Less: Distribution services reserve (16,545 ) (11,037 ) Less: Discount reserve (10,801 ) (14,344 ) Less: Uncollectible accounts reserve (2) (45,859 ) (49,423 ) Accounts receivable, net $ 226,373 $ 240,753 (1) Includes estimated $44.3 million as of March 31, 2018 and December 31, 2017 , receivable due from Turing Pharmaceuticals AG ("Turing") for reimbursement of Daraprim® chargebacks and Medicaid rebate liabilities pursuant to an Asset Purchase Agreement between the Company and Turing dated August 7, 2015 (the "Turing APA"). In accordance with the terms of the Turing APA and in accordance with federal laws and regulations, the Company receives, 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 government programs, health plans and other health care providers for products 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®. Refer to "Note 18. Legal and Regulatory Matters" for a description of the Company's suit against Turing related to, among other matters, Turing's failure to reimburse the Company for chargebacks and Medicaid rebate liabilities when due. (2) As a result of the uncertainty of collection from Turing that developed during the first quarter of 2016, the Company recorded a reserve of $48.0 million as of March 31, 2016, which represented the full amount of the estimated receivable due from Turing. During the fourth quarter of 2016, the Company received a $7.7 million payment from Turing. During the three month period ended March 31, 2018, there were no changes to the $44.3 million estimated receivable due from Turing that was fully reserved. A rollforward of the rebate and chargeback reserves activity for the three months ended March 31, 2018 and the year ended December 31, 2017 is as follows (in thousands): Three Months Ended Year Ended Rebate reserve March 31, 2018 December 31, 2017 Beginning balance $ 181,611 $ 293,816 Provision recorded during the period for Impax Generics rebates 104,339 642,447 Credits issued during the period for Impax Generics rebates (173,931 ) (754,652 ) Ending balance $ 112,019 $ 181,611 The payment mechanisms for rebates in the Impax Generics and Impax Specialty Pharma divisions are different, which impacts the location on the Company's consolidated balance sheets. Impax Generics rebates are classified as "Accounts receivable, net" on the Company's consolidated balance sheets. Impax Specialty Pharma rebates are classified as "Accrued expenses" on the Company's consolidated balance sheets. Three Months Ended Year Ended Chargeback reserve March 31, 2018 December 31, 2017 Beginning balance $ 136,891 $ 151,978 Provision recorded during the period 248,590 1,212,039 Credits issued during the period (284,965 ) (1,227,126 ) Ending balance $ 100,516 $ 136,891

INVENTORY

INVENTORY	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory, net of carrying value reserves, as of March 31, 2018 and December 31, 2017 consisted of the following (in thousands): March 31, 2018 December 31, 2017 Raw materials $ 65,275 $ 63,732 Work in process 12,510 3,046 Finished goods 94,272 104,187 Total inventory 172,057 170,965 Less: Non-current inventory 13,466 12,494 Total inventory - current $ 158,591 $ 158,471 Inventory carrying value reserves were $55.0 million and $71.6 million at March 31, 2018 and December 31, 2017 , respectively. The carrying value of unapproved inventory less reserves was $15.7 million and $19.3 million at March 31, 2018 and December 31, 2017 , respectively.

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	3 Months Ended
	Mar. 31, 2018
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, 2018 December 31, 2017 Land $ 3,500 $ 3,500 Buildings and improvements 94,608 96,775 Equipment 82,639 82,442 Office furniture and equipment 10,527 11,082 Construction-in-progress 46,990 46,622 Property, plant and equipment, gross 238,264 240,421 Less: Accumulated depreciation (114,976 ) (115,608 ) Property, plant and equipment, net $ 123,288 $ 124,813 Depreciation expense was $2.9 million and $7.8 million for the three months ended March 31, 2018 and 2017, respectively. Unpaid vendor invoices relating to purchases of property, plant and equipment of $0.6 million and $4.3 million , which were accrued as of March 31, 2018 and 2017, 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, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND GOODWILL	INTANGIBLE ASSETS AND GOODWILL Intangible Assets Changes in the amount of intangible assets for the three months ended March 31, 2018 are set forth in the table below. The table shows 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): Marketed Product Rights IPR&D and Royalties Total Company Gross Carrying Value Accumulated Amortization Intangible Assets, Net Non-amortized Value Intangible Assets, Net Balance as of December 31, 2017 $ 430,009 $ (205,545 ) $ 224,464 $ 38,003 $ 262,467 Additions — — — 1,000 1,000 Amortization — (14,473 ) (14,473 ) — (14,473 ) Balance as of March 31, 2018 $ 430,009 $ (220,018 ) $ 209,991 $ 39,003 $ 248,994 Amortization The Company recognized amortization expense of $14.5 million for the three months ended March 31, 2018 and $17.2 million for the three months ended March 31, 2017 , in cost of revenues in the consolidated statements of operations presented. Impairment The Company did no t recognize any intangible asset impairment charges during the first quarter of 2018. During the first quarter of 2017, the Company recognized a total of $45.4 million of intangible asset impairment charges, of which $39.3 million was recognized in cost of revenues impairment charges and $6.1 million was recognized in in-process research and development impairment charges on the Company's consolidated statement of operations. The $45.4 million impairment charge was almost entirely attributable to three products, two of which are currently marketed products and one of which is an IPR&D product, all acquired as part of the Teva Transaction. For the currently marketed products, the impairment charge was the result of continued significant price and volume erosion during the first quarter of 2017 without an offsetting increase in customer demand, resulting in significantly lower expected future cash flows. For the IPR&D product, the impairment charge was the result of increased estimated research and development expenses and a delay in the anticipated product launch due to a change in the regulatory strategy to secure FDA approval of such product. Goodwill Goodwill had a carrying value on the Company's consolidated balance sheets of $207.3 million at both March 31, 2018 and December 31, 2017 . At March 31, 2018 , the Company attributed $147.6 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, 2018
Payables and Accruals [Abstract]
ACCRUED EXPENSES	ACCRUED EXPENSES The following table sets forth the Company’s accrued expenses (in thousands): March 31, 2018 December 31, 2017 Payroll-related expenses $ 16,267 $ 38,415 Product returns 80,781 76,293 Accrued shelf stock 13,165 7,525 Government rebates 52,934 73,970 Accrued litigation settlements (1) 51,900 4,900 Legal and professional fees 12,185 14,005 Estimated Teva and Allergan chargebacks and rebates (2) 13,277 13,277 Accrued profit sharing and royalty expenses 11,713 8,373 Other 16,454 11,369 Total accrued expenses $ 268,676 $ 248,127 (1) See “Note 18. Legal and Regulatory Matters” for a description of the claims and settlements. (2) In connection with our August 2016 acquisition of certain assets from Teva Pharmaceuticals USA, Inc. ("Teva") and Allergan plc ("Allergan") in the Teva Transaction, the Company agreed to manage the payment process for certain commercial chargebacks and rebates on behalf of Teva and Allergan related to products each of Teva and Allergan sold into the channel prior to the Company's acquisition of the products. On August 18, 2016, the Company received a payment totaling $42.4 million from Teva and Allergan, which represented their combined estimate of the amount of commercial chargebacks and rebates to be paid by the Company on their behalf to wholesalers who purchased products from Teva and Allergan prior to the closing. Pursuant to the agreed upon transition services, Teva and Allergan are obligated to reimburse the Company for additional payments related to chargebacks and rebates for products they sold into the channel prior to the closing and made on their behalf in excess of the $42.4 million . If the total payments made by the Company on behalf of Teva and Allergan are less than $42.4 million , the Company is obligated to refund the difference to Teva and/or Allergan. As of March 31, 2018 , the Company had paid $29.1 million related to chargebacks and rebates on behalf of Teva and/or Allergan as described above and $13.3 million remained in accrued expenses on the Company's consolidated balance sheet. 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 rollforward of the return reserve activity for the three months ended March 31, 2018 and the year ended December 31, 2017 is as follows (in thousands): Three Months Ended Year Ended Returns reserve March 31, 2018 December 31, 2017 Beginning balance $ 76,293 $ 72,888 Provision related to sales recorded in the period 19,709 47,709 Credits issued during the period (15,221 ) (44,304 ) Ending balance $ 80,781 $ 76,293

DEBT

DEBT	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
DEBT	DEBT Royal Bank of Canada Credit Facilities On August 3, 2016, the Company entered into a restatement agreement with Royal Bank of Canada, as administrative agent, and the lenders and guarantors party thereto (the "Restatement Agreement"). The Restatement Agreement amends and restates the Company's existing Revolving Credit Facility Agreement (as amended and restated and amended to date, the "Amended and Restated Credit Agreement") to, among other things, (i) add a term loan feature to allow for the borrowing of up to $400.0 million of term loans (the "Term Loan Facility") by the Company in accordance with the terms of the Amended and Restated Credit Agreement, (ii) increase the aggregate principal amount of revolving loans permitted under the Amended and Restated Credit Agreement (the "Revolving Credit Facility," and, together with the Term Loan Facility, the "RBC Credit Facilities"), from $100.0 million to $200.0 million , and (iii) extend the maturity date of the Revolving Credit Facility from August 4, 2020 to August 3, 2021. On March 27, 2017, the Company entered into Amendment No. 1 by and among the Company, Royal Bank of Canada, as administrative agent, and the lenders party thereto (the “Amendment”) to the Amended and Restated Credit Agreement. Borrowings under the Amended and Restated Credit Agreement 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 0.25% based on the Company's total net leverage ratio. Up to $12.5 million of the Revolving Credit Facility is available for issuance of letters of credit and any such letters of credit will reduce the amount available under the Revolving Credit Facility on a dollar-for-dollar basis. The Company is required to pay a commitment fee to the lenders on the average daily unused portion of the Revolving Credit Facility at 0.50% or 0.375% per annum, depending on the Company's total net leverage ratio. The Amended and Restated Credit Agreement contains certain negative covenants (subject to exceptions, materiality thresholds and other allowances) including, without limitation, negative covenants that limit the Company's and its restricted subsidiaries' ability to incur additional debt, guarantee other obligations, grant liens on assets, make loans, acquisitions or other investments, dispose of assets, make optional payments in connection with or modify certain debt instruments, pay dividends or make other payments on capital stock, engage in mergers or consolidations, enter into arrangements that restrict the Company's and its restricted subsidiaries' ability to pay dividends or grant liens, engage in transactions with affiliates, or change its fiscal year. Prior to the effective date of the Amendment on March 27, 2017, the Amended and Restated Credit Agreement also included a financial maintenance covenant whereby the Company must not permit its total net leverage ratio in any 12 -month period to exceed 5.00 :1.00, as tested at the end of each fiscal quarter. Effective as of March 27, 2017 and pursuant to the Amendment, the total net leverage ratio financial covenant was replaced with a new senior secured net leverage ratio financial covenant. Pursuant to the Amendment, the Company must not permit its senior secured net leverage ratio to exceed 2.50 :1.00 and the interest coverage ratio to be less than 3.00 :1.00, in each case in any 12 -month period, as tested at the end of each fiscal quarter. The Company was in compliance with all of its covenants under the Amended and Restated Credit Agreement as of March 31, 2018 . The Amended and Restated Credit Agreement contains events of default, including, without limitation (subject to customary grace periods and materiality thresholds), events of default upon (i) the failure to make payments pursuant to the terms of the Amended and Restated Credit Agreement, (ii) violation of covenants, (iii) incorrectness of representations and warranties, (iv) cross-default and cross-acceleration to other material indebtedness, (v) bankruptcy events, (vi) material monetary judgments (to the extent not covered by insurance), (vii) certain matters arising under the Employee Retirement Income Security Act of 1974, as amended, that could reasonably be expected to result in a material adverse effect, (viii) the actual or asserted invalidity of the documents governing the RBC Credit Facilities, any material guarantees or the security interests (including priority thereof) required under the Amended and Restated Credit Agreement and (ix) the occurrence of a change of control (as defined therein). Upon the occurrence of certain events of default, the obligations under the Amended and Restated Credit Agreement may be accelerated and any remaining commitments thereunder may be terminated. The full amount of proceeds from the Term Loan Facility of $400.0 million , along with $196.4 million of cash were used to finance the Teva Transaction (including transaction costs) at closing on August 3, 2016. As of March 31, 2018 , $199.7 million Revolving Credit Facility remained available to the Company for working capital and other general corporate purposes. In connection with the Term Loan Facility, the Company incurred $11.0 million of debt issuance costs for banking, legal and accounting fees and other expenses during the third quarter of 2016. In connection with the Amendment, the Company incurred $0.8 million of debt issuance costs for banking fees during the first quarter of 2017. These debt issuance costs were recorded on the Company's consolidated balance sheet as a reduction to the current and long-term portions of debt related to the Term Loan Facility. These deferred debt issuance costs will be accreted to interest expense over the term of the debt using the effective interest method. In connection with the increase in the aggregate principal amount of revolving loans permitted under the Revolving Credit Facility, the Company incurred $0.8 million of debt issuance costs for banking fees which were recorded as an asset with current and long-term portions on the Company's consolidated balance sheet. These deferred debt issuance costs, in addition to the $0.3 million balance remaining from the initial $100.0 million revolving credit facility, will be amortized to interest expense over the term of the Revolving Credit Facility using the straight-line method. For the three months ended March 31, 2018 and 2017, the Company recognized $4.7 million and $4.4 million , respectively, of interest expense related to the Term Loan Facility, of which $4.2 million and $3.8 million , respectively, was cash and $0.5 million and $0.6 million , respectively, was non-cash accretion of the debt discount recorded for deferred debt issuance costs. As of March 31, 2018 , the Term Loan Facility had a carrying value of $313.0 million , of which $17.9 million is classified as current debt and $295.1 million is classified as long-term debt on the Company's consolidated balance sheets. The Term Loan Facility requires the Company to make quarterly principal payments of $5.0 million beginning December 2016 through June 2021, and the remaining principal balance is payable in August 2021. As of March 31, 2018 , the outstanding principal amount for the Term Loan Facility was $320.0 million . Loss on Early Extinguishment of Debt - Voluntary Prepayment of $50.0 Million of Principal - RBC Term Loan Facility On February 28, 2017, the Company made a voluntary prepayment in the amount of $50.3 million under its Term Loan Facility, representing $50.0 million of principal amount and $0.3 million of accrued interest thereon. As a result of this voluntary prepayment, for the quarter ended March 31, 2017, the Company recorded a loss on early extinguishment of debt of $1.2 million to write-off a pro rated portion of the related unaccreted debt issuance costs. 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 on 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 815-40). On November 6, 2017, the Company entered into a supplemental indenture (the “First Supplemental Indenture”) to the Indenture. The First Supplemental Indenture was entered into to effectuate certain amendments to the Indenture in connection with the consummation of Impax’s consent solicitation with respect to the Notes on October 30, 2017, seeking consents from holders of the Notes to the proposed amendments as set forth in the First Supplemental Indenture. See “Note 1. Basis of Presentation” for additional information on the BCA with Amneal. The First Supplemental Indenture (a) amends a covenant in the Indenture relating to the Company’s corporate existence, (b) allows the Company to satisfy its reporting requirements by providing reports of any parent entity, (c) adds a provision to the Indenture requiring the Company to make and consummate a tender offer for any outstanding notes under the Indenture, and (d) expressly authorizes the Company to consummate the transactions contemplated by the BCA. 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 five 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 11. 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 470-20, Debt with Conversion and Other Options , and FASB ASC Topic 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 subsequently amended the Company's Restated Certificate of Incorporation to increase the authorized number of shares of the Company’s common stock in December 2015, the debt discount remained and continues to be accreted to interest expense. See “Note 11. 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 consolidated balance sheets as a reduction to the carrying value of the debt and is being accreted to interest expense over the term of the debt using the effective interest method. For the three months ended March 31, 2018 and March 31, 2017 , the Company recognized $9.2 million and $8.7 million , respectively, of interest expense related to the Notes, of which $3.0 million and $3.0 million , respectively, was cash and $6.2 million and $5.7 million , respectively, 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 $476.0 million and $469.9 million as of March 31, 2018 and December 31, 2017 , respectively. Accrued interest payable on the Notes of $3.5 million as of March 31, 2018 and $0.5 million as of December 31, 2017 is included in accrued expenses on the Company's consolidated balance sheets.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2018
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, 2018 and December 31, 2017 . 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 74,080,636 shares have been issued and 73,836,907 shares were outstanding as of March 31, 2018 . 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, 2018 (in thousands): Shares issued 74,081 Stock options outstanding (1) 3,042 Conversion of Notes payable (2) 9,471 Warrants outstanding (see below) 9,471 Total shares of common stock issued and reserved for issuance 96,065 (1) See “Note 13. Share-based Compensation.” (2) See “Note 10. Debt.” Warrants As discussed in “Note 10. 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. Retained Earnings Effective January 1, 2018, the Company adopted FASB ASU 2014-09, “ Revenue from Contracts with Customers ” (Topic 606) regarding the accounting for and disclosures of revenue recognition. The Company adopted the new guidance using the modified retrospective transition method, which resulted in a $0.4 million charge to opening retained earnings for 2018.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2018
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 (loss) 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, 2018 and 2017 (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Basic Loss Per Common Share: Net loss $ (130,932 ) $ (98,431 ) Weighted-average common shares outstanding 72,266 71,594 Basic loss per share $ (1.81 ) $ (1.37 ) Diluted Loss Per Common Share: Net loss $ (130,932 ) $ (98,431 ) Add-back of interest expense on outstanding convertible notes payable, net of tax — (1) — (1) Adjusted net loss $ (130,932 ) $ (98,431 ) Weighted-average common shares outstanding 72,266 71,594 Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance — (2) — (2) Weighted-average incremental shares assuming conversion of outstanding notes payable — (1) — (1) Diluted weighted-average common shares outstanding 72,266 (2) 71,594 (2) Diluted loss per share $ (1.81 ) $ (1.37 ) (1) For the three months ended March 31, 2018 and 2017, 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 outstanding Notes. (2) For the three months ended March 31, 2018 and 2017, 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, 2018 , shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, included 9.47 million warrants outstanding, 9.47 million shares for conversion of outstanding Notes payable, 3.04 million stock options outstanding and 1.56 million non-vested restricted stock awards. As of March 31, 2017 , 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 Notes payable, 3.34 million stock options outstanding and 2.21 million non-vested restricted stock awards.

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2018
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 option and share of restricted stock over its vesting period. Stock options and restricted stock awards are granted under the Company’s Fourth Amended and Restated 2002 Equity Incentive Plan (the “2002 Plan”) and generally vest over a four year period and, in the case of stock options, have a term of 10 years. Impax Laboratories, Inc. Fourth Amended and Restated 2002 Equity Incentive Plan The aggregate number of shares of common stock authorized for issuance pursuant to the Company's 2002 Plan is 18,050,000 shares. There were 2,192,269 and 2,324,997 stock options outstanding as of March 31, 2018 and December 31, 2017 , respectively, and 1,560,684 and 1,861,489 non-vested restricted stock awards outstanding as of March 31, 2018 and December 31, 2017 , respectively, under the 2002 Plan. 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 zero stock options outstanding as of March 31, 2018 and December 31, 2017 , under the 1999 Plan. The Company has ceased granting equity awards under the 1999 Plan. Awards Granted Out of Plan - CEO Inducement On March 27, 2017, the Company granted Paul M. Bisaro, its new President and Chief Executive Officer, an option to purchase 850,000 shares of the Company’s common stock pursuant to the terms of his Employment Agreement dated as of March 24, 2017 with the Company. The grant was made in accordance with NASDAQ’s employment inducement grant exemption and therefore was not granted under a stockholder approved plan. The grant is subject to the terms of an option agreement with Mr. Bisaro to evidence the award. There were 850,000 stock options outstanding related to this grant as of March 31, 2018 . The following table summarizes all of the Company's stock option activity for the current year through March 31, 2018 : Stock Options Number of Weighted- Outstanding at December 31, 2017 3,174,997 $ 18.36 Options exercised (127,648 ) 9.28 Options forfeited (5,080 ) 8.38 Outstanding at March 31, 2018 3,042,269 $ 18.76 Options exercisable at March 31, 2018 1,875,982 $ 20.08 As of March 31, 2018 , stock options outstanding and exercisable had average remaining contractual lives of 6.59 years and 5.70 years, respectively. Also, as of March 31, 2018 , stock options outstanding and exercisable each had aggregate intrinsic values of $13.7 million and $7.1 million , respectively, and restricted stock awards outstanding had an aggregate intrinsic value of $30.4 million . 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 Weighted- Non-vested at December 31, 2017 1,861,489 $ 25.36 Vested (103,144 ) 26.54 Forfeited (197,661 ) 26.15 Non-vested at March 31, 2018 1,560,684 $ 25.19 Included in the 103,144 shares of restricted stock vested during the three months ended March 31, 2018 are 49,427 shares with a weighted-average fair value of $20.39 per share that were withheld for income tax withholding purposes upon vesting of such awards from stockholders who elected to net share settle such tax withholding obligation. As of March 31, 2018 , the Company had 2,130,036 shares available for issuance of either stock options or restricted stock awards under the 2002 Plan. Although there were also 296,921 shares available for issuance under the 1999 Plan, the Company has ceased granting equity awards under this plan. Additionally, the Company had 1,499,596 shares available for issuance under its 2001 Non-Qualified Employee Stock Purchase Plan, as amended (“ESPP”). The Company's Board of Directors terminated the ESPP effective after the expiration of the final purchase period prior to December 31, 2017. As of March 31, 2018 , the Company had total unrecognized share-based compensation expense of $33.0 million related to all of its share-based awards, which is expected to be recognized over a weighted average period of 1.5 years. The intrinsic value of options exercised during the three months ended March 31, 2018 and 2017 was $11.8 million and immaterial, respectively. The total fair value of restricted stock which vested during the three months ended March 31, 2018 and 2017 was $2.7 million and $2.3 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 over 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 March 31, 2018 2017 Cost of revenues $ 520 $ 1,584 Selling, general and administrative 3,196 1,423 Research and development 1,100 3,950 Total $ 4,816 $ 6,957

RESTRUCTURINGS

RESTRUCTURINGS	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
RESTRUCTURINGS	RESTRUCTURINGS Consolidation and Improvement Plan On May 10, 2017, the Company announced that it has initiated a series of actions designed to improve manufacturing and research and development ("R&D") efficiencies, capitalize on growth opportunities, improve profitability and mitigate current challenges. The actions include: • Consolidating all of Generic R&D, U.S. manufacturing and packing operations to its Hayward, California facility; • Continuing the previously announced closure of the Middlesex, New Jersey manufacturing site, which will now include the closure of the Middlesex Generic R&D site as further discussed below under "Middlesex, New Jersey Manufacturing and Packaging Operations" and "Middlesex, New Jersey Generic R&D"; • Reorganizing certain functions including quality, engineering and supply chain operations as further described below under "Technical Operations Reduction-in-Force"; • Reviewing strategic alternatives for the Company’s Taiwan facility, including a sale of the facility as further described below under "Sale of Impax Laboratories (Taiwan), Inc." and • Rationalizing the generic portfolio to eliminate low-value products and streamline operations such as the Company's divestment during the second quarter of 2017 of 29 ANDAs and one NDA for approved non-strategic generic products, the vast majority of which were not marketed, and all acquired as part of the Tower Acquisition, as described above under "Note 8. Intangible Assets and Goodwill." By consolidating activities as outlined above, the Company expects to achieve cost savings and operating efficiency benefits while maintaining the infrastructure and expertise needed to capitalize on product and pipeline strengths. The Company currently expects to incur estimated charges for each initiative as described below. There are no charges currently expected to be incurred related to the rationalization of the generic product portfolio. 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. As of March 31, 2018 this plan has been completed. As a result of the restructuring, 215 positions were eliminated. The Company incurred aggregate pre-tax charges of $43.6 million in connection with this plan through the period ended March 31, 2018 and does not anticipate any future charges. The following is a summary of the cumulative charges incurred by major type of cost (in thousands): Type of Cost Amount Incurred Employee retention and severance payments $ 12,752 Technical transfer of products 9,716 Asset impairment and accelerated depreciation charges 20,900 Facilities lease terminations and asset retirement obligations 209 Legal and professional fees 9 Total estimated restructuring charges $ 43,586 Employee retention and severance payments are being accrued over the estimated service period. For the three months ended March 31, 2018 and 2017 the Company recorded expense of $0.2 million and $4.3 million , respectively, to cost of revenues on the consolidated statement of operations. For the three months ended March 31, 2018 and March 31, 2017 , the Company incurred charges to general and administrative expenses as follows (in thousands): Three Months Ended March 31, 2018 2017 Employee retention and severance payments $ 25 $ 1,480 Technical transfer of products 172 1,188 Asset impairment and accelerated depreciation charges — 1,561 Facilities lease terminations and asset retirement obligations — 93 Total $ 197 $ 4,322 A rollforward of the charges incurred to general and administrative expense for the three months ended March 31, 2018 is as follows (in thousands): Balance as of Expensed/ Balance as of December 31, 2017 Accrued Expense Cash Payments Non-Cash Items March 31, 2018 Employee retention and severance payments $ 7,386 $ 25 $ (7,073 ) $ — $ 338 Technical transfer of products — 172 (172 ) — — Legal and professional fees 209 — — — 209 Total $ 7,595 $ 197 $ (7,245 ) $ — $ 547 As of March 31, 2018 the Company recognized a liability of $0.5 million , in accrued expenses on the Company's consolidated balance sheet and anticipates remaining payments to be made through the second quarter of 2018. Middlesex, New Jersey Generic R&D In May 2017, as part of its Consolidation and Improvement Plan, the Company announced its plan to close its Middlesex, New Jersey Generic R&D site and consolidate all Generic R&D activities to its Hayward, California facility. As a result, the Company eliminated a total of 31 positions in Middlesex. In connection with this Generic R&D consolidation, the Company incurred aggregate pre-tax charges for employee termination benefits, program termination costs and accelerated depreciation charges of $3.4 million through the end of 2017. As of March 31, 2018 , $2.8 million of employee termination benefits and program termination costs had been paid. Sale of Middlesex, New Jersey Assets In the fourth quarter of 2017, management completed an evaluation of the assets located at the Company's Middlesex, New Jersey facilities in accordance with ASC 360 - Property, Plant and Equipment ("ASC 360") to determine whether all of the "held for sale" criteria under subsection 360-10-45-9 has been met. Based upon management's evaluation of the criteria under ASC 360, the Middlesex, New Jersey assets were determined to meet all of the "held for sale" criteria. As a result, the Company completed an impairment assessment related to the new book value of the assets of $5.6 million and based upon the estimated fair value less estimated costs to sell the assets the Company recorded a fixed asset impairment charges of $3.3 million in the Generic segment of its consolidated statement of operation for the year ended December 31, 2017. On January 16, 2018, the Company sold all of its outstanding membership interest in CorePharma LLC, its wholly-owned subsidiary that held certain assets and leases to the Middlesex, New Jersey facility, including certain specified assets within the entity, to a third party for a purchase price of $2.2 million and received the cash during the first quarter of 2018. Technical Operations Reduction-in-Force In March 2017, the Company's management determined that a reduction-in-force was necessary in the Company's technical operations group in order to achieve greater operational efficiencies and to further streamline the organization. The Company identified 48 positions for elimination and recognized all expense as of December 31, 2017. In connection with this reduction-in-force, the Company incurred aggregate pre-tax charges for employee termination benefits and other associated costs of $3.7 million through the end of 2017. For the three months ended March 31, 2018 and 2017 , the Company recorded $0.0 million and $1.8 million , respectively, of employee termination benefits and other associated costs to cost of revenues on the consolidated statement of operations. The accrued balance of $1.7 million as of December 31, 2017 was paid during the first quarter of 2018. Sale of Impax Laboratories (Taiwan), Inc. In May 2017, as part of its Consolidation and Improvement Plan, the Company announced that it was reviewing strategic alternatives for its Taiwan facility, including a sale of the facility to a qualified buyer capable of reliably producing Rytary® in accordance with FDA requirements as the Company’s CMO or, in the alternative, a closure of the facility following the completion of the technology transfer process to allow Rytary® to be manufactured either in the Company’s Hayward, California facility or at a CMO. Following this announcement, management completed an evaluation of the Taiwan facility in accordance with ASC 360 to determine whether all of the “held for sale” criteria under subsection 360-10-45-9 had been met. Based upon the evaluation of the criteria, including management's assessment of whether it was probable that a sale to a qualified buyer could be completed within one year, the Taiwan facility was determined to be “held and used” as of May 31, 2017. Following the "held and used" determination, management next evaluated the Taiwan facility for recoverability. Recoverability of property is evaluated by a comparison of the carrying amount of an asset or asset group to the future net undiscounted cash flows expected to be generated by the asset or asset group. As the activities at the Taiwan facility were primarily focused on manufacturing Rytary®, which product represented the majority of the unit volume produced and cash flows generated, the Taiwan facility was included in the Impax Specialty Pharma asset group. Based upon the cash flows expected to be generated by the Impax Specialty Pharma asset group, management determined that there was no impairment of the asset group which included the Taiwan facility as of May 31, 2017. As of May 31, 2017, the remaining useful life of the Taiwan facility was estimated to be two years , which was based on the estimated time required to complete the technology transfer process for Rytary® and reflected the new pattern of consumption of the expected benefits of the facility. The Company will recognize accelerated depreciation expense on a straight-line basis through May 31, 2019 to write the building and equipment associated with the Taiwan facility down to their estimated salvage values. For the year ended December 31, 2017 the Company recorded accelerated depreciation of $9.1 million . After May 31, 2017 the Company continued to assess whether the Taiwan facility met the ASC 360 criteria. In the fourth quarter of 2017 based upon management's valuation of the criteria the Taiwan facility was determined to meet all of the “held for sale” criteria. As a result, excluding assets and liabilities subject to customary working capital adjustment, the Company completed an impairment assessment of the net book value of $91.7 million related to the net assets to be sold, and based upon an estimated fair value less estimated costs to sell for the net assets, the Company recorded an asset impairment charge of $74.1 million in the Company's consolidated statement of operations, of which $73.6 million related to property, plant and equipment. The remaining assets and liabilities associated with the Taiwan entity, which were part of the Impax Specialty Pharma segment, were reclassified as held for sale. On February 6, 2018, the Company completed its sale of the outstanding shares of Impax Laboratories (Taiwan), Inc. to Bora Pharmaceuticals C. Ltd ("Bora") for $16.5 million in cash, a $2.0 million note receivable and customary working capital settlement. In connection with closing this transaction and settling working capital, the Company recorded an additional loss on disposal of $1.2 million primarily related to final working capital adjustments. As a result of the sale, the Company reclassified foreign currency translation adjustments, a gain, of $ 0.8 million from accumulated other comprehensive income to loss on sale of assets on the consolidated statement of operations.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company has historically calculated the provision for income taxes during interim reporting periods by applying an estimate of the annual effective tax rate for the full fiscal year to “ordinary” income or loss (pretax income or loss excluding unusual or infrequently occurring discrete items) for the reporting period. For the three months ended March 31, 2017 , however, the Company began using the discrete effective tax rate method to calculate taxes. The Company had determined that since small changes in estimated “ordinary” income (or loss) would result in significant changes in the estimated annual effective tax rate, the historical method would not provide a reliable estimate for the three months ended March 31, 2017 . During the three months ended March 31, 2018 and 2017 , the Company recognized an aggregate consolidated tax benefit of ($7.3) million and aggregate consolidated tax expense of $30.9 million, respectively, for U.S. domestic and foreign income taxes. The effective tax rates for the three month periods ended March 31, 2018 and 2017 were 5.3% and (45.8)% , respectively. The amount of tax benefit recorded for the three months ended March 31, 2018 and the tax expense recorded for the three months ended March 31, 2017 reflect the Company’s estimates as of such dates using the discrete effective tax rate method. Management assesses the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit the use of the existing deferred tax assets. A significant piece of objective evidence that management evaluated was the cumulative loss incurred over the three year period ended December 31, 2017 . Such objective evidence limits management's ability to consider other subjective evidence, such as projected taxable income. On the basis of this evaluation, as of December 31, 2017 , the Company recorded a valuation allowance of $185.9 million . During the three months ended March 31, 2018 , the Company considered new evidence, both positive and negative, that could impact the Company's assessment with regard to future realization of deferred tax assets. Based on the cumulative loss over the three year period ended March 31, 2018 , an additional valuation allowance in the amount of $22.6 million was recorded against the gross deferred tax asset balance for a total valuation allowance of $208.5 million as of March 31, 2018 . Although the Company continued to be in a three year cumulative loss as of the first quarter 2018 and incurred a loss in the first quarter of 2018, the Company recorded a tax benefit of ($7.3) million due to its ability to fully utilize the carryback of the $20.7 million capital loss on the sale of its Taiwan subsidiary in February 2018. Under the Internal Revenue Code's ordering of losses rules, the capital loss amount displaced the Net Operating Loss (NOL) previously utilized and the amount is essentially converted into an NOL before being carried back three years. This $20.7 million capital loss carryback loss was able to be benefited at the 35% rate in the 2015 carryback year.

ALLIANCE AND COLLABORATION AGRE

ALLIANCE AND COLLABORATION AGREEMENTS	3 Months Ended
	Mar. 31, 2018
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 the 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 Milestone 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 $100.0 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. Pursuant to the terms of the Amended and Restated Shire Agreement, the Company is required to pay to Shire a specified profit share based on sales of the AG Product and a specified profit share based on sales of the Company's generic Adderall XR® product. The Company began selling its generic Adderall XR® product during the second quarter of 2016. The Company accrued a profit share payable to Shire of $0.1 million and $0.8 million during the three months ended March 31, 2018 and 2017, respectively, based on sales of the AG Product and the Company's generic Adderall XR® product, in each case with a corresponding charge included in the costs of revenues line on the consolidated statements of operations. 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 10 currently approved products in the United States and its territories; the parties agreed in 2015 to terminate development efforts of one product under the Tolmar Agreement that had been pending approval at the FDA. Under the terms of the Tolmar Agreement, Tolmar is responsible for developing and manufacturing the products, and the Company is responsible for marketing and selling of the products. As of March 31, 2018 , the Company was currently marketing and selling four approved 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 up to an aggregate amount of $25.0 million upon the achievement of certain specified milestone events. As of March 31, 2018 , the Company had paid a total of $20.0 million to Tolmar upon the achievement of certain specified milestone events, including $12.0 million upon the achievement of a regulatory milestone event and $5.0 million upon the achievement of a commercialization event, and does not currently expect to make any additional milestone payments under the agreement. The Company is also required to pay a profit share to Tolmar on sales of the topical products, of which it accrued a profit share payable to Tolmar of $0.6 million and $0.9 million during the three months ended March 31, 2018 and 2017 , respectively, with a corresponding charge included in the cost of revenues line in the Company’s consolidated statement of operations. Strategic Alliance Agreement with Teva The Company is a party to a Strategic Alliance Agreement dated as of June 27, 2001 with Teva, 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. As of March 31, 2018 , the Company was supplying Teva with oxybutynin extended release tablets (Ditropan XL® 5 mg, 10 mg and 15 mg extended release tablets); 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 Teva Agreement. Distribution, License, Development and Supply Agreement with AstraZeneca UK Limited In January 2012, the Company entered into an agreement with AstraZeneca UK Limited to distribute branded products under the terms of a Distribution, License, Development and Supply Agreement ("AZ Agreement"). The parties subsequently entered into a First Amendment to the AZ Agreement dated May 31, 2016 (as amended, the "AZ Amendment"). 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. Under the terms of the AZ Amendment, under certain conditions and depending on the nature and terms of the study agreed to with the FDA, the Company agreed to conduct, at its own expense, the juvenile toxicity study and pediatric study required by the FDA under the Pediatric Research Equity Act (“PREA”) for approval of the nasal formulation of Zomig ® for the acute treatment of migraine in pediatric patients ages six through eleven years old, as further described in the study protocol mutually agreed to by the parties (the “PREA Study”). In consideration for the Company conducting the PREA Study at its own expense, the AZ Amendment provides for the total royalty payments payable by the Company to AstraZeneca on net sales of Zomig ® products under the AZ Agreement to be reduced by certain specified amounts beginning from the quarter ended June 30, 2016 and through the quarter ended December 31, 2020, with such reduced royalty amounts totaling an aggregate amount of $30.0 million . In the event the royalty reduction amounts exceed the royalty payments payable by the Company to AstraZeneca pursuant to the AZ Agreement in any given quarter, AstraZeneca will be required to pay the Company an amount equal to the difference between the royalty reduction amount and the royalty payment payable by the Company to AstraZeneca. The Company’s commitment to perform the PREA Study may be terminated, without penalty, under certain circumstances as set forth in the AZ Amendment. 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. As discussed above, pursuant to the AZ Amendment, the total royalty payments payable by the Company to AstraZeneca on net sales of Zomig ® products under the AZ Agreement is reduced by certain specified amounts beginning from the quarter ended June 30, 2016 and through the quarter ended December 31, 2020, with such reduced royalty amounts totaling an aggregate amount of $30.0 million . The Company accrued a royalty payable to AstraZeneca of $2.2 million and $3.3 million during the three months ended March 31, 2018 and 2017 , respectively, with a corresponding charge included in the cost of revenues line on the consolidated statements of operations. Mebendazole 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 “Mebendazole Product Acquisition Agreement”) with 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. Pursuant to the Mebendazole Product Acquisition Agreement, the Company was required to pay certain milestone payments up to an aggregate amount of $3.5 million upon the approval and launch of the mebendazole tablet product; the Company paid the $3.5 million to Teva during the quarter ended March 31, 2016 upon 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 Mebendazole Product Acquisition Agreement.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2018
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 2027. Purchase Order Commitments As of March 31, 2018 , the Company had $103.5 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.

LEGAL AND REGULATORY MATTERS

LEGAL AND REGULATORY MATTERS	3 Months Ended
	Mar. 31, 2018
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 is 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 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 June 2016, the Court entered an amended judgment in both cases 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. Appeals in these cases are pending. The appeals with respect to the Grunenthal patents are stayed. The Company and ThoRx moved to dismiss the appeals concerning the Endo patents. That motion is pending. 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 ThoRx’s 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 were dismissed in February 2018. 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. The case went to trial in September 2016. On March 29, 2017, the District Court issued a Trial Opinion finding the asserted patents valid and infringed. On April 17, 2017, the District Court entered a Final Judgment and Injunction that, inter alia , bars FDA approval of Lannett’s proposed generic product prior to May 29, 2021. On May 12, 2017, Lannett filed a Notice of Appeal with the United States Court of Appeals for the Federal Circuit. Briefing of Lannett’s appeal has been completed and oral argument occurred on April 5, 2018. Impax Laboratories Inc., et al. v. Par Pharmaceutical, Inc. (Zomig®) On September 23, 2016, the Company filed suit against Par Pharmaceutical, Inc. (“Par”) in the United States District Court for the District of Delaware, alleging patent infringement based on the filing of the Par ANDA relating to Zolmitriptan Nasal Spray, 2.5 mg and 5 mg, generic to Zomig® Nasal Spray. On October 12, 2016, the parties stipulated to stay the case pending the outcome of the related case, Impax Laboratories Inc., et al. v. Lannett matter described above. On April 24, 2017, the parties stipulated that the stay shall remain in effect until the Impax Laboratories Inc., et al. v. Lannett matter is fully resolved. As such, Par has not yet filed an answer or counterclaims to the Company’s complaint. The 30-month stay of approval for applicable to the Par ANDA has been tolled pending resumption of this case. Impax Laboratories Inc., et al. v. Actavis Laboratories FL, Inc. and Actavis Pharma Inc. (Rytary ® ) In September 2015, the Company filed suit against Actavis Laboratories FL, Inc. and Actavis Pharma Inc. (collectively, “Actavis”) in the United States District Court for the District of New Jersey, alleging patent infringement of U.S. Patent Nos. 7,094,427; 8,377,474; 8,454,998; 8,557,283; 9,089,607; 9,089,608, based on the filing of the Actavis ANDA relating to carbidopa and levodopa extended release capsules, generic to Rytary ® . The Company filed related actions alleging infringement of later-issued U.S. Patent No. 9,463,246 in December 2016 and of later-issued U.S. Patent No. 9,533,046 in May 2017. Both related actions were consolidated with the lead action. On December 15, 2017, the Patent and Trademark Office issued an Ex Parte Reexamination Certificate canceling all claims of the ‘427 patent; the parties subsequently stipulated to dismiss with prejudice all claims and counterclaims relating to the ‘427 patent. Fact discovery and claim construction briefing have concluded and a claim construction hearing was held on April 26, 2017. On May 9, 2017, the District Court issued a decision interpreting certain claim terms in dispute in the litigation. Subject to reservation of all rights to appeal the Court’s May 9, 2017 decision, the parties stipulated to dismiss without prejudice all claims and counterclaims relating to the ‘474, ‘998, and ‘607 patents, and the Court entered an order recognizing this stipulation on June 8, 2017. The parties have completed expert discovery and Actavis filed a summary judgment motion on October 23, 2017. On March 8, 2018, the Court issued an Opinion and Order, granting in part Actavis’s motion for summary judgment. A four day trial is scheduled to begin on May 14, 2018. Impax Laboratories, Inc. v. Sandoz Inc. ( Rytary ® ) On March 31, 2017, the Company filed suit against Sandoz Inc. in the United States District Court for the District of New Jersey, alleging infringement of U.S. Patent Nos. 7,094,427; 8,377,474; 8,454,998; 8,557,283; 9,089,607; 9,089,608; 9,463,246; and 9,533,046, based on the filing of Sandoz’s ANDA relating to carbidopa and levodopa extended release capsules, generic to Rytary ® . Sandoz answered the complaint on March 22, 2018. Fact discovery has not yet commenced. Impax Laboratories, Inc. v. Zydus Pharmaceuticals USA, Inc. and Cadila Healthcare Ltd. (Rytary ® ) On December 21, 2017, Impax filed suit against Zydus Pharmaceuticals USA, Inc. and Cadila Healthcare Ltd. (collectively, “Zydus”) in the United States District Court for the District of New Jersey, alleging infringement of U.S. Patent No. 9,089,608, based on the filing of Zydus’s ANDA relating to carbidopa and levodopa extended release capsules, generic to Rytary ® . Zydus has not yet answered or otherwise responded to the Complaint. Bristol-Myers Squibb Company, et al. v. Impax Laboratories, Inc.(Apixiban) On April 10, 2017, Bristol-Myers Squibb Company and Pfizer Inc. filed suit against the Company in the United States District Court for the District of Delaware alleging patent infringement based on the filing of the Company’s ANDA related to Apixaban Tablets, 2.5 mg and 5 mg, generic to Eliquis ® . The Company responded to the complaint on June 2, 2017 and Plaintiffs further responded on June 22, 2017. On September 22, 2017, the parties jointly filed a proposed schedule with the Court, proposing that the Company’s case and a number of related cases be consolidated. On November 3, 2017, the Court consolidated the related cases and set the case schedule. Fact discovery has commenced. The trial is scheduled for October 15, 2019. Biogen MA Inc. v. Impax Laboratories, Inc. (Dimethyl Fumarate) On June 26, 2017, Biogen MA Inc. filed suit against the Company in the U.S. District Court for the District of Delaware alleging patent infringement based on the filing of the Company’s ANDA relating to Dimethyl Fumarate 120 and 240 mg capsules, generic to Tecfidera ® . The Company answered the complaint on October 16, 2017. On February 2, 2017, the Court consolidated the related cases and set the case schedule. A trial with respect to this complaint by Biogen MA Inc. is scheduled to begin on December 9, 2019. On March 5, 2018, Biogen International GmbH filed a complaint in the matter Biogen International GmbH v. Impax Laboratories, Inc. , based on the same ANDA, alleging infringement of two additional patents. The Company answered that complaint on March 26, 2018. No further schedule has been set with respect to this complaint. Shire Development LLC, et al. v. Impax Laboratories, Inc. (Amphetamine Mixed Salts) On April 13, 2018, Shire Development LLC, Shire LLC, and Shire US Inc. filed suit against the Company in the United States District Court for the District of Delaware alleging patent infringement based on the filing of the Company’s ANDA related to Amphetamine Mixed Salts Extended Release Oral Capsules, 12.5 mg, 25 mg, 37.5 mg, and 50 mg, generic to Mydayis ® . The Company has not yet responded to the complaint, and no schedule has yet been set for the case. 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 District Court granted in part and denied in part defendants’ motion to dismiss the consolidated amended complaints. On October 16, 2017, the Court certified the Direct Purchaser Plaintiffs’ and End-Payor Plaintiffs’ classes. On October 30, 2017, the Company filed a petition for interlocutor appeal challenging the Court’s certification of the End-Payor Plaintiffs’ class and motions for Summary Judgment were filed on November 1, 2017. On January 25, 2018, the Court denied Plaintiffs’ and Impax’s summary judgment motions. Trial began on March 12, 2018. During March 2018, the Company separately settled all claims with the direct purchaser plaintiff class, retailer plaintiffs and the end payor plaintiff class for a total settlement amount of $84.5 million . The settlements with the class plaintiffs are subject to court approval. The settlement with the direct purchaser plaintiff class was preliminarily approved by the Court on March 12, 2018, and a fairness hearing is scheduled for July 11, 2018. The settlement with the end payor plaintiff class was preliminarily approved by the Court on April 5, 2018. Opana ER® FTC Antitrust Suit 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. 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. In July 2016, the defendants filed a motion to dismiss the complaint, and a motion to sever the claims regarding Opana® ER from claims with respect to a separate settlement agreement that was challenged by the FTC. On October 20, 2016, the Court granted the motion to sever, formally terminating the suit against the Company, with an order that the FTC re-file no later than November 3, 2016 and dismissed the motion to dismiss as moot. On October 25, 2016, the FTC filed a notice of voluntary dismissal. On January 19, 2017, the FTC filed a Part 3 Administrative complaint against the Company with similar allegations regarding the Company’s June 2010 settlement agreement with Endo that resolved patent litigation in connection with the submission of the Company’s ANDA for generic original Opana® ER. The Company filed its answer to the Administrative Complaint on February 7, 2017. Trial concluded on November 15, 2017. Post-trial briefing is complete and closing arguments were held on February 15, 2018. A decision is pending. Opana ER® Antitrust Class Actions From June 2014 to April 2015, 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 States District Court for the Middle District of Louisiana 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 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 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. 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. In re Generic Pharmaceuticals Pricing Antitrust Litigation From March 2016 to April 2017, 22 complaints were filed as class actions on behalf of direct and indirect purchasers against manufacturers of generic digoxin and doxycycline and the Company alleging a conspiracy to fix, maintain and/or stabilize prices of these generic products. From January 2017 to April 2017, three complaints were filed on behalf of indirect purchasers against manufacturers of generic lidocaine/prilocaine and the Company alleging a conspiracy to fix, maintain and/or stabilize prices of these generic products. On March 2, 2016, Plaintiff International Union of Operating Engineers Local 30 Benefits 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. The plaintiff filed an amended complaint on June 9, 2016. On March 25, 2016, Plaintiff Tulsa Firefighters Health and Welfare Trust, 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 25, 2016, Plaintiff NECA-IBEW Welfare 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 April 4, 2016, Plaintiff Pipe Trade Services MN, 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 April 25, 2016

SEGMENT INFORMATION

SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2018
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 generic products are reported under the caption "Impax Generics, net." 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® (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 branded products are reported under the caption “Impax Specialty Pharma, net.” 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 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 in “Management's Discussion and Analysis of Financial Condition and Results of Operations - Critical Accounting Policies and Estimates” and "Item 15. Exhibits and Financial Statement Schedules - Notes to Consolidated Financial Statements - Note 2. Summary of Significant Accounting Policies" to the Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2017. 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, 2018 Impax Impax Corporate Total Revenues, net $ 83,141 $ 59,214 $ — $ 142,355 Cost of revenues 95,037 17,038 — 112,075 Selling, general and administrative 7,556 17,620 32,147 57,323 Research and development 9,616 2,680 — 12,296 Litigation, settlements and related charges 84,597 940 — 85,537 (Loss) income before income taxes $ (113,665 ) $ 20,936 $ (45,493 ) $ (138,222 ) Three Months Ended March 31, 2017 Impax Impax Corporate Total Revenues, net $ 134,147 $ 50,256 $ — $ 184,403 Cost of revenues 103,335 16,897 — 120,232 Cost of revenues impairment charges 39,280 — — 39,280 Selling, general and administrative 6,468 16,330 24,257 47,055 Research and development 17,396 5,093 — 22,489 In-process research and development impairment charges 6,079 — — 6,079 Litigation, settlements and related charges 368 704 — 1,072 (Loss) income before income taxes $ (38,779 ) $ 11,232 $ (39,983 ) $ (67,530 ) Significant Products The Company generally consolidates net revenue by "product family," meaning that it consolidates net revenue from products containing the same active ingredient(s) irrespective of dosage strength, delivery method or packaging size. The Company's significant product families, as determined based on net revenue, and their percentage of the Company's consolidated net revenue for each of the three months ended March 31, 2018 and 2017 are set forth below (in thousands): Segment Product Family Three Months Ended March 31, 2018 $ % Impax Specialty Pharma Rytary® family $ 26,508 19 % (1) Impax Generics Epinephrine Auto-Injector family (generic Adrenaclick®) $ 14,783 10 % (2) Impax Specialty Pharma Albenza family $ 13,607 10 % (3) Impax Specialty Pharma Oxymorphone HCI ER family $ 13,387 9 % (4) Impax Specialty Pharma Zomig® family $ 10,478 7 % (5) Segment Product Family Three Months Ended March 31, 2017 $ % Impax Generics Epinephrine Auto-Injector family (generic Adrenaclick®) $ 20,318 11 % (2) Impax Generics Rytary® family $ 19,905 11 % (1) Impax Specialty Pharma Oxymorphone HCI ER family $ 18,970 10 % (4) Impax Specialty Pharma Budesonide family $ 15,827 9 % (6) Impax Generics Amphetamine Salts ER (CII) family (generic Adderall®) $ 12,173 7 % (7) (1) Rytary® product family consists of the capsules product in four different strengths and is indicated for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication or manganese intoxication. (2) Epinephrine Auto-Injector (generic Adrenaclick®) product family consists of the injector product in two different strengths and is indicated in the emergency treatment of allergic reactions (Type 1) including anaphylaxis. (3) Albenza® product family consists of one strength and is indicated for the treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium and the treatment of cystic hydatid disease of the liver, lung and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus. (4) Oxymorphone Hydrochloride Extended Release product family consists of the oxymorphone hydrochloride extended release tablet formulation of the product in seven different strengths and is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate. (5) Zomig® product family consists of products in tablet, orally disintegrating tablet and nasal spray dosage forms, each dosage form in two different strengths, and is indicated for the acute treatment of migraine with or without aura in adults. Zomig® (zolmitriptan) Nasal Spray is also indicated in pediatric patients 12 years of age or older. (6) Budesonide product family consists of the budesonide inhalation suspension formulation of the product in two different strengths and is indicated for the maintenance treatment of asthma and as prophylactic therapy in children 12 months to eight years of age. (7) Amphetamine Salts extended release (ER) capsules, CII (generic Adderall XR®) product family consists of the capsules product in six different strengths and is indicated for the treatment of attention deficit hyperactivity disorder. Foreign Operations During 2017 we announced that we entered into a stock and asset purchase agreement with Bora Pharmaceuticals Co., Ltd., pursuant to which we agreed to sell Impax Taiwan, our wholly-owned subsidiary which owns our manufacturing facility in Taiwan, R.O.C. The sale of Impax Taiwan subsequently closed in February 2018. On the Company's consolidated balance sheets at March 31, 2018 and December 31, 2017 , Impax Taiwan represents $0.0 million and $22.9 million , respectively, of net carrying value of assets, composed principally of a building and manufacturing equipment which are included in assets and liabilities held for sale. See "Note 14. Restructurings" for additional information related to the closure or sale of the Taiwan facility.

SUPPLEMENTARY FINANCIAL INFORMA

SUPPLEMENTARY FINANCIAL INFORMATION	3 Months Ended
	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
SUPPLEMENTARY FINANCIAL INFORMATION	SUPPLEMENTARY FINANCIAL INFORMATION Selected financial information for the quarterly period noted is as follows: (in thousands, except share and per share amounts) Quarter Ended March 31, 2018 Revenue: Impax Generics, gross $ 474,043 Less: Chargebacks 240,041 Rebates 104,339 Product Returns 16,174 Other credits 31,329 Impax Generic Product sales, net 82,160 Rx Partner 909 Other Revenues 72 Impax Generic Division revenues, net 83,141 Impax Specialty Pharma, gross 97,215 Less: Chargebacks 8,548 Rebates 5,601 Product Returns 3,535 Other credits 20,317 Impax Specialty Pharma, net 59,214 Total revenues 142,355 Gross Profit 30,280 Net Loss $ (130,932 ) Net loss per common share: Basic $ (1.81 ) Diluted $ (1.81 ) Weighted-average common shares outstanding: Basic 72,265,794 Diluted 72,265,794 (in thousands, except share and per share amounts) Quarter Ended March 31, 2017 Revenue: Impax Generics, gross $ 630,672 Less: Chargebacks 298,744 Rebates 164,792 Product Returns 9,733 Other credits 28,481 Impax Generic Product sales, net 128,922 Rx Partner 5,159 Other Revenues 66 Impax Generic Division revenues, net 134,147 Impax Specialty Pharma, gross 84,133 Less: Chargebacks 9,828 Rebates 4,483 Product Returns 1,844 Other credits 17,722 Impax Specialty Pharma, net 50,256 Other Revenues — Impax Specialty Pharma, net 50,256 Total revenues 184,403 Gross profit 24,891 Net loss $ (98,431 ) Net loss per common share: Basic $ (1.37 ) Diluted $ (1.37 ) Weighted-average common shares outstanding: Basic 71,594,472 Diluted 71,594,472

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS As described in “Note 1. Basis of Presentation” Impax completed its business combination with Amneal on May 4, 2018 pursuant to the BCA. The following events occurred subsequent to the closing (the “Closing”) of the transactions contemplated by the BCA: • Shares of Impax common stock ceased trading on the NASDAQ Global Select Market (“Nasdaq”) at the close of business on May 4, 2018. On May 4, 2018, Nasdaq filed a notification on Form 25 with the SEC with respect to shares of Impax common stock to request removal of Impax common stock from listing on the NASDAQ and from registration under Section 12(b) of the Securities and Exchange Act of 1934, as amended. • In accordance with the terms of the BCA, in connection with the Closing on May 4, 2018, (i) each share of Impax common stock was cancelled and automatically converted into the right to receive one fully paid and nonassessable share of Class A common stock of Amneal Pharmaceuticals, Inc. (“Class A Common Stock”); (ii) approximately 1.3 million of Impax common stock issued with respect to unvested restricted stock awards issued and outstanding immediately prior to the Closing were fully vested and exchanged for shares of Class A Common Stock; and (iii) approximately 3.0 million outstanding stock options issued under the Impax equity plans or as inducement grants outstanding immediately prior to the Closing were fully vested and exchanged into for options to acquire a number of shares of Class A Common Stock equal to the number of shares of Impax Common Stock subject to such Impax Option immediately prior to the Closing at a price per share equal to the exercise price per share of Impax common stock otherwise purchasable pursuant to such Impax option. • In connection with the Closing, the Company repaid in full all outstanding amounts under its Amended and Restated Credit Agreement, dated as of August 3, 2016 and as amended on March 27, 2017 by and among Impax, Royal Bank of Canada, as administrative agent and collateral agent, and the lenders and other parties from time to time party thereto (the “Credit Agreement”), and terminated the Credit Agreement and all commitments by the lenders to extent further credit thereunder. • In connection with the Closing, on May 4, 2018, the Company, Amneal Pharmaceuticals, Inc. and Wilmington Trust, National Association, as trustee (the “Trustee”), entered into the Second Supplemental Indenture (the “Second Supplemental Indenture”) with respect to the Indenture dated as of June 30, 2015 (the “Indenture”), as amended by the First Supplemental Indenture dated as of November 6, 2017, governing the Company’s 2.00% Convertible Senior Notes due 2022 (the “Notes”). The Second Supplemental Indenture (x) made New Amneal a party to the Indenture and (y) changed the right to convert each $1,000 principal amount of the Notes into a right to convert such principal amount of Notes into shares of Class A Common Stock, cash or a combination of cash and shares of Class A Common Stock, at the Company’s election, in each case reflecting a conversion rate of 15.7853 shares of Class A Common Stock per $1,000 principal amount of Notes surrendered for conversion. Further, as described in “Note 10. Debt”, concurrently with the offering of the Notes, the Company had entered into convertible note hedge transactions (the “Convertible Note Hedge Transactions”) with respect to shares of the Company’s common stock with Royal Bank of Canada (the “Counterparty”). On May 7, 2018 Impax and the Counterparty entered into a termination agreement terminating in full the Convertible Note Hedge Transactions and the Warrant Transactions (the “Termination Agreement”). • As of May 4, 2018 and subsequent to that date, certain executives separated from their respective positions at Impax. Each of these separations constituted a termination of employment by Impax without cause following a change of control for purposes of the executives’ respective employment agreements. These executives will receive certain termination benefits during the second quarter in accordance with their employment agreements. The foregoing subsequent events did not impact the Impax Statement of Operations, Balance Sheet or Cash Flow Statement for the quarter ended March 31, 2018.

SUMMARY OF SIGNIFICANT ACCOUN28

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance In May 2014, the Financial Accounting Standards Board ("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 provided 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 is effective for annual and interim periods beginning after December 15, 2017. In April 2016 and May 2016, the FASB issued ASU 2016-10, " Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing " and ASU 2016-12, " Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ," respectively. Both of these updates provide improvements and clarification to the previously issued revenue recognition guidance. The new standard can be adopted using one of two methods: the full retrospective method, which requires the standard to be applied to each prior period presented, or the modified retrospective method, which requires the cumulative effect of adoption to be recognized as an adjustment to opening retained earnings in the period of adoption. Under Topic 606, the Company will recognize revenue earlier on certain of its less significant transactions involving third-party collaborations and other arrangements. The Company adopted the new guidance effective January 1, 2018 using the modified retrospective transition method, which resulted in a $0.4 million charge to opening retained earnings for 2018 which otherwise would have been recognized as revenue in the three months ended March 31, 2018. There was no effect to total revenues for the three months ended March 31, 2018 as a result of adopting the new accounting on January 1, 2018. The amounts as reported in these unaudited consolidated financial statements were the same as the amounts would have been if the previous accounting guidance was in effect. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): " Classification of Certain Cash Receipts and Cash Payments, " with guidance intended to reduce the diversity in practice regarding how certain cash receipts and cash payments are presented and classified within the statement of cash flows. The update addresses eight specific cash flow issues including debt prepayment or debt extinguishment costs, the settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)), distributions received from equity method investees, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In October 2016, the FASB issued ASU-2016-16, Income Taxes (Topic 740): " Intra-Entity Transfers of Assets Other Than Inventory, " with guidance intended to more faithfully represent the economics of intra-entity asset transfers. The update clarifies that entities must recognize the income tax consequences of intra-entity asset transfers, other than inventory, when the transfer occurs. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU-2017-01, Business Combinations (Topic 805): "Clarifying the Definition of a Business," with guidance intended to assist entities in evaluating whether transactions should be accounted for as acquisitions (or disposals) of businesses. The update provides a screen to determine whether an integrated set of assets and activities constitute a business. If the screen is not met, the guidance (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) removes the evaluation of whether a market participant could replace the missing elements. The guidance is effective for annual and interim periods beginning after December 15, 2017 and will be applied prospectively. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): "Scope of Modification Accounting," which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The guidance is effective for annual and interim periods beginning after December 15, 2017. The amendments in this ASU are applied prospectively to an award modified on or after the adoption date. The Company adopted this guidance as of January 1, 2018 and the guidance did not have any impact on the Company's consolidated financial statements. Accounting Guidance Issued Not Yet Adopted 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 will have on its consolidated financial statements and related disclosures. The Company's expects the implementation of this standard to have an impact on its consolidated financial statements and related disclosures as it has aggregate future minimum lease payments of $28.1 million as of December 31, 2017 under the current portfolio of non-cancelable leases for land, office space, and manufacturing, warehouse and research and development facilities with various expiration dates between January 2018 and December 2027. The Company anticipates recognition of additional assets and corresponding liabilities related to these leases on its consolidated balance sheet.
Revenue Recognition	Product Revenue, 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 product revenues may include deductions from the gross sales price related to estimates for chargebacks, rebates and administrative fees, distribution service fees, returns, shelf-stock adjustments, and other pricing adjustments. The Company records an estimate for these deductions as variable consideration 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 retail pharmacy chains, group purchasing organizations, 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 and Administrative Fees - The Company maintains various rebate and administrative fee 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 for credit expired product under the terms of its published Returns Goods Policy. 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. Profit share and other revenues The Company has entered into agreements, where it licenses certain rights to its products to customers. For arrangements that include sales-based royalties, the Company recognizes revenue when the related sales occur.

FAIR VALUE MEASUREMENT AND FI29

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 and December 31, 2017 are indicated below (in thousands): As of March 31, 2018 Fair Value Measurement Based on Carrying Fair Value Quoted Prices in Active Markets Significant Significant Unobservable Assets Deferred Compensation Plan asset (1) $ 42,594 $ 42,594 $ — $ 42,594 $ — Liabilities Term Loan Facility due August 2021, current portion (2) $ 20,000 $ 20,000 $ — $ 20,000 $ — Term Loan Facility due August 2021, long-term portion (2) $ 300,000 $ 300,000 $ — $ 300,000 $ — 2% Convertible Senior Notes due June 2022 (3) $ 600,000 $ 597,000 $ 597,000 $ — $ — Deferred Compensation Plan liabilities (1) $ 33,899 $ 33,899 $ — $ 33,899 $ — Contingent consideration (4) $ — $ — $ — $ — $ — As of December 31, 2017 Fair Value Measurement Based on Carrying Fair Value Quoted Prices in Active Markets Significant Significant Unobservable Assets Deferred Compensation Plan asset (1) $ 43,023 $ 43,023 $ — $ 43,023 $ — Liabilities Term Loan Facility due August 2021, current portion (2) $ 20,000 $ 20,000 $ — $ 20,000 $ — Term Loan Facility due August 2021, long-term portion (2) $ 305,000 $ 305,000 $ — $ 305,000 $ — 2% Convertible Senior Notes due June 2022 (3) $ 600,000 $ 579,378 $ 579,378 $ — $ — Deferred Compensation Plan liabilities (1) $ 33,413 $ 33,413 $ — $ 33,413 $ — Contingent consideration (4) $ — $ — $ — $ — $ — (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 policies (COLIs), 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, 2018 and December 31, 2017 represents the unaccreted discount related to deferred debt issuance costs. (3) 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, 2018 and December 31, 2017 represents the unaccreted discounts related to deferred debt issuance costs and bifurcation of the conversion feature of the notes. (4) Under the terms of the Termination Agreement which was effective August 3, 2016 and was executed as part of our acquisition of certain assets from Teva Pharmaceuticals USA, Inc. and Allergan plc, the ("Teva Transaction"). the Company could be contractually obligated to make payments up to $40.0 million based on the achievement of certain commercial and time-based milestones associated with is methylphenidate hydrochloride product. A discounted cash flow calculation model was used to value the contingent consideration using significant unobservable inputs, including the probability and timing of successful product launch, the expected number of product competitors in the market at the time of launch (as defined in the Termination Agreement) and the expected number of such competitors in the market o the one-year launch anniversary date. The Company conducted a review of the underlying inputs and assumptions at March 31, 2018 and December 31, 2017, and based on timing and probability of the product launch, and corresponding number of competitors expected to be in the market at both launch and the one-year anniversary of launch, the Company concluded that the fair value of its contingent consideration was zero .

ACCOUNTS RECEIVABLE (Tables)

ACCOUNTS RECEIVABLE (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of Accounts Receivable Composition	The composition of accounts receivable, net is as follows (in thousands): March 31, 2018 December 31, 2017 Gross accounts receivable (1) $ 512,113 $ 634,059 Less: Rebate reserve (112,019 ) (181,611 ) Less: Chargeback reserve (100,516 ) (136,891 ) Less: Distribution services reserve (16,545 ) (11,037 ) Less: Discount reserve (10,801 ) (14,344 ) Less: Uncollectible accounts reserve (2) (45,859 ) (49,423 ) Accounts receivable, net $ 226,373 $ 240,753 (1) Includes estimated $44.3 million as of March 31, 2018 and December 31, 2017 , receivable due from Turing Pharmaceuticals AG ("Turing") for reimbursement of Daraprim® chargebacks and Medicaid rebate liabilities pursuant to an Asset Purchase Agreement between the Company and Turing dated August 7, 2015 (the "Turing APA"). In accordance with the terms of the Turing APA and in accordance with federal laws and regulations, the Company receives, 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 government programs, health plans and other health care providers for products 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®. Refer to "Note 18. Legal and Regulatory Matters" for a description of the Company's suit against Turing related to, among other matters, Turing's failure to reimburse the Company for chargebacks and Medicaid rebate liabilities when due. (2) As a result of the uncertainty of collection from Turing that developed during the first quarter of 2016, the Company recorded a reserve of $48.0 million as of March 31, 2016, which represented the full amount of the estimated receivable due from Turing. During the fourth quarter of 2016, the Company received a $7.7 million payment from Turing. During the three month period ended March 31, 2018, there were no changes to the $44.3 million estimated receivable due from Turing that was fully reserved.
Schedules of Rebate and Chargeback Activity	A rollforward of the rebate and chargeback reserves activity for the three months ended March 31, 2018 and the year ended December 31, 2017 is as follows (in thousands): Three Months Ended Year Ended Rebate reserve March 31, 2018 December 31, 2017 Beginning balance $ 181,611 $ 293,816 Provision recorded during the period for Impax Generics rebates 104,339 642,447 Credits issued during the period for Impax Generics rebates (173,931 ) (754,652 ) Ending balance $ 112,019 $ 181,611 The payment mechanisms for rebates in the Impax Generics and Impax Specialty Pharma divisions are different, which impacts the location on the Company's consolidated balance sheets. Impax Generics rebates are classified as "Accounts receivable, net" on the Company's consolidated balance sheets. Impax Specialty Pharma rebates are classified as "Accrued expenses" on the Company's consolidated balance sheets. Three Months Ended Year Ended Chargeback reserve March 31, 2018 December 31, 2017 Beginning balance $ 136,891 $ 151,978 Provision recorded during the period 248,590 1,212,039 Credits issued during the period (284,965 ) (1,227,126 ) Ending balance $ 100,516 $ 136,891

INVENTORY (Tables)

INVENTORY (Tables)	3 Months Ended
	Mar. 31, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory, Net of Carrying Value Reserves	Inventory, net of carrying value reserves, as of March 31, 2018 and December 31, 2017 consisted of the following (in thousands): March 31, 2018 December 31, 2017 Raw materials $ 65,275 $ 63,732 Work in process 12,510 3,046 Finished goods 94,272 104,187 Total inventory 172,057 170,965 Less: Non-current inventory 13,466 12,494 Total inventory - current $ 158,591 $ 158,471

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment, net of accumulated depreciation, consists of the following (in thousands): March 31, 2018 December 31, 2017 Land $ 3,500 $ 3,500 Buildings and improvements 94,608 96,775 Equipment 82,639 82,442 Office furniture and equipment 10,527 11,082 Construction-in-progress 46,990 46,622 Property, plant and equipment, gross 238,264 240,421 Less: Accumulated depreciation (114,976 ) (115,608 ) Property, plant and equipment, net $ 123,288 $ 124,813

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The table shows 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): Marketed Product Rights IPR&D and Royalties Total Company Gross Carrying Value Accumulated Amortization Intangible Assets, Net Non-amortized Value Intangible Assets, Net Balance as of December 31, 2017 $ 430,009 $ (205,545 ) $ 224,464 $ 38,003 $ 262,467 Additions — — — 1,000 1,000 Amortization — (14,473 ) (14,473 ) — (14,473 ) Balance as of March 31, 2018 $ 430,009 $ (220,018 ) $ 209,991 $ 39,003 $ 248,994

ACCRUED EXPENSES (Tables)

ACCRUED EXPENSES (Tables)	3 Months Ended
	Mar. 31, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	The following table sets forth the Company’s accrued expenses (in thousands): March 31, 2018 December 31, 2017 Payroll-related expenses $ 16,267 $ 38,415 Product returns 80,781 76,293 Accrued shelf stock 13,165 7,525 Government rebates 52,934 73,970 Accrued litigation settlements (1) 51,900 4,900 Legal and professional fees 12,185 14,005 Estimated Teva and Allergan chargebacks and rebates (2) 13,277 13,277 Accrued profit sharing and royalty expenses 11,713 8,373 Other 16,454 11,369 Total accrued expenses $ 268,676 $ 248,127 (1) See “Note 18. Legal and Regulatory Matters” for a description of the claims and settlements. (2) In connection with our August 2016 acquisition of certain assets from Teva Pharmaceuticals USA, Inc. ("Teva") and Allergan plc ("Allergan") in the Teva Transaction, the Company agreed to manage the payment process for certain commercial chargebacks and rebates on behalf of Teva and Allergan related to products each of Teva and Allergan sold into the channel prior to the Company's acquisition of the products. On August 18, 2016, the Company received a payment totaling $42.4 million from Teva and Allergan, which represented their combined estimate of the amount of commercial chargebacks and rebates to be paid by the Company on their behalf to wholesalers who purchased products from Teva and Allergan prior to the closing. Pursuant to the agreed upon transition services, Teva and Allergan are obligated to reimburse the Company for additional payments related to chargebacks and rebates for products they sold into the channel prior to the closing and made on their behalf in excess of the $42.4 million . If the total payments made by the Company on behalf of Teva and Allergan are less than $42.4 million , the Company is obligated to refund the difference to Teva and/or Allergan. As of March 31, 2018 , the Company had paid $29.1 million related to chargebacks and rebates on behalf of Teva and/or Allergan as described above and $13.3 million remained in accrued expenses on the Company's consolidated balance sheet.
Schedule of Return Reserve Activity	A rollforward of the return reserve activity for the three months ended March 31, 2018 and the year ended December 31, 2017 is as follows (in thousands): Three Months Ended Year Ended Returns reserve March 31, 2018 December 31, 2017 Beginning balance $ 76,293 $ 72,888 Provision related to sales recorded in the period 19,709 47,709 Credits issued during the period (15,221 ) (44,304 ) Ending balance $ 80,781 $ 76,293

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 (in thousands): Shares issued 74,081 Stock options outstanding (1) 3,042 Conversion of Notes payable (2) 9,471 Warrants outstanding (see below) 9,471 Total shares of common stock issued and reserved for issuance 96,065 (1) See “Note 13. Share-based Compensation.” (2) See “Note 10. Debt.”

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 and 2017 (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Basic Loss Per Common Share: Net loss $ (130,932 ) $ (98,431 ) Weighted-average common shares outstanding 72,266 71,594 Basic loss per share $ (1.81 ) $ (1.37 ) Diluted Loss Per Common Share: Net loss $ (130,932 ) $ (98,431 ) Add-back of interest expense on outstanding convertible notes payable, net of tax — (1) — (1) Adjusted net loss $ (130,932 ) $ (98,431 ) Weighted-average common shares outstanding 72,266 71,594 Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance — (2) — (2) Weighted-average incremental shares assuming conversion of outstanding notes payable — (1) — (1) Diluted weighted-average common shares outstanding 72,266 (2) 71,594 (2) Diluted loss per share $ (1.81 ) $ (1.37 ) (1) For the three months ended March 31, 2018 and 2017, 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 outstanding Notes. (2) For the three months ended March 31, 2018 and 2017, 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, 2018 , shares issuable but not included in the Company's calculation of diluted EPS, which could potentially dilute future earnings, included 9.47 million warrants outstanding, 9.47 million shares for conversion of outstanding Notes payable, 3.04 million stock options outstanding and 1.56 million non-vested restricted stock awards. As of March 31, 2017 , 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 Notes payable, 3.34 million stock options outstanding and 2.21 million non-vested restricted stock awards.

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes all of the Company's stock option activity for the current year through March 31, 2018 : Stock Options Number of Weighted- Outstanding at December 31, 2017 3,174,997 $ 18.36 Options exercised (127,648 ) 9.28 Options forfeited (5,080 ) 8.38 Outstanding at March 31, 2018 3,042,269 $ 18.76 Options exercisable at March 31, 2018 1,875,982 $ 20.08
Schedule of Share-based Compensation, Restricted Stock Awards Activity	A summary of the non-vested restricted stock awards is as follows: Restricted Stock Awards Number of Weighted- Non-vested at December 31, 2017 1,861,489 $ 25.36 Vested (103,144 ) 26.54 Forfeited (197,661 ) 26.15 Non-vested at March 31, 2018 1,560,684 $ 25.19
Schedule of Employee Share-based Compensation Expense	The amount of share-based compensation expense recognized by the Company is as follows (in thousands): Three Months Ended March 31, 2018 2017 Cost of revenues $ 520 $ 1,584 Selling, general and administrative 3,196 1,423 Research and development 1,100 3,950 Total $ 4,816 $ 6,957

RESTRUCTURINGS (Tables)

RESTRUCTURINGS (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Summary of Restructuring Charges	For the three months ended March 31, 2018 and March 31, 2017 , the Company incurred charges to general and administrative expenses as follows (in thousands): Three Months Ended March 31, 2018 2017 Employee retention and severance payments $ 25 $ 1,480 Technical transfer of products 172 1,188 Asset impairment and accelerated depreciation charges — 1,561 Facilities lease terminations and asset retirement obligations — 93 Total $ 197 $ 4,322 The following is a summary of the cumulative charges incurred by major type of cost (in thousands): Type of Cost Amount Incurred Employee retention and severance payments $ 12,752 Technical transfer of products 9,716 Asset impairment and accelerated depreciation charges 20,900 Facilities lease terminations and asset retirement obligations 209 Legal and professional fees 9 Total estimated restructuring charges $ 43,586
Schedule of Restructuring Reserve by Type of Cost	A rollforward of the charges incurred to general and administrative expense for the three months ended March 31, 2018 is as follows (in thousands): Balance as of Expensed/ Balance as of December 31, 2017 Accrued Expense Cash Payments Non-Cash Items March 31, 2018 Employee retention and severance payments $ 7,386 $ 25 $ (7,073 ) $ — $ 338 Technical transfer of products — 172 (172 ) — — Legal and professional fees 209 — — — 209 Total $ 7,595 $ 197 $ (7,245 ) $ — $ 547

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2018
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, 2018 Impax Impax Corporate Total Revenues, net $ 83,141 $ 59,214 $ — $ 142,355 Cost of revenues 95,037 17,038 — 112,075 Selling, general and administrative 7,556 17,620 32,147 57,323 Research and development 9,616 2,680 — 12,296 Litigation, settlements and related charges 84,597 940 — 85,537 (Loss) income before income taxes $ (113,665 ) $ 20,936 $ (45,493 ) $ (138,222 ) Three Months Ended March 31, 2017 Impax Impax Corporate Total Revenues, net $ 134,147 $ 50,256 $ — $ 184,403 Cost of revenues 103,335 16,897 — 120,232 Cost of revenues impairment charges 39,280 — — 39,280 Selling, general and administrative 6,468 16,330 24,257 47,055 Research and development 17,396 5,093 — 22,489 In-process research and development impairment charges 6,079 — — 6,079 Litigation, settlements and related charges 368 704 — 1,072 (Loss) income before income taxes $ (38,779 ) $ 11,232 $ (39,983 ) $ (67,530 )
Schedule of Product Information	The Company's significant product families, as determined based on net revenue, and their percentage of the Company's consolidated net revenue for each of the three months ended March 31, 2018 and 2017 are set forth below (in thousands): Segment Product Family Three Months Ended March 31, 2018 $ % Impax Specialty Pharma Rytary® family $ 26,508 19 % (1) Impax Generics Epinephrine Auto-Injector family (generic Adrenaclick®) $ 14,783 10 % (2) Impax Specialty Pharma Albenza family $ 13,607 10 % (3) Impax Specialty Pharma Oxymorphone HCI ER family $ 13,387 9 % (4) Impax Specialty Pharma Zomig® family $ 10,478 7 % (5) Segment Product Family Three Months Ended March 31, 2017 $ % Impax Generics Epinephrine Auto-Injector family (generic Adrenaclick®) $ 20,318 11 % (2) Impax Generics Rytary® family $ 19,905 11 % (1) Impax Specialty Pharma Oxymorphone HCI ER family $ 18,970 10 % (4) Impax Specialty Pharma Budesonide family $ 15,827 9 % (6) Impax Generics Amphetamine Salts ER (CII) family (generic Adderall®) $ 12,173 7 % (7) (1) Rytary® product family consists of the capsules product in four different strengths and is indicated for the treatment of Parkinson’s disease, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide intoxication or manganese intoxication. (2) Epinephrine Auto-Injector (generic Adrenaclick®) product family consists of the injector product in two different strengths and is indicated in the emergency treatment of allergic reactions (Type 1) including anaphylaxis. (3) Albenza® product family consists of one strength and is indicated for the treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium and the treatment of cystic hydatid disease of the liver, lung and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus. (4) Oxymorphone Hydrochloride Extended Release product family consists of the oxymorphone hydrochloride extended release tablet formulation of the product in seven different strengths and is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate. (5) Zomig® product family consists of products in tablet, orally disintegrating tablet and nasal spray dosage forms, each dosage form in two different strengths, and is indicated for the acute treatment of migraine with or without aura in adults. Zomig® (zolmitriptan) Nasal Spray is also indicated in pediatric patients 12 years of age or older. (6) Budesonide product family consists of the budesonide inhalation suspension formulation of the product in two different strengths and is indicated for the maintenance treatment of asthma and as prophylactic therapy in children 12 months to eight years of age. (7) Amphetamine Salts extended release (ER) capsules, CII (generic Adderall XR®) product family consists of the capsules product in six different strengths and is indicated for the treatment of attention deficit hyperactivity disorder.

SUPPLEMENTARY FINANCIAL INFOR40

SUPPLEMENTARY FINANCIAL INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Selected financial information for the quarterly period noted is as follows: (in thousands, except share and per share amounts) Quarter Ended March 31, 2018 Revenue: Impax Generics, gross $ 474,043 Less: Chargebacks 240,041 Rebates 104,339 Product Returns 16,174 Other credits 31,329 Impax Generic Product sales, net 82,160 Rx Partner 909 Other Revenues 72 Impax Generic Division revenues, net 83,141 Impax Specialty Pharma, gross 97,215 Less: Chargebacks 8,548 Rebates 5,601 Product Returns 3,535 Other credits 20,317 Impax Specialty Pharma, net 59,214 Total revenues 142,355 Gross Profit 30,280 Net Loss $ (130,932 ) Net loss per common share: Basic $ (1.81 ) Diluted $ (1.81 ) Weighted-average common shares outstanding: Basic 72,265,794 Diluted 72,265,794 (in thousands, except share and per share amounts) Quarter Ended March 31, 2017 Revenue: Impax Generics, gross $ 630,672 Less: Chargebacks 298,744 Rebates 164,792 Product Returns 9,733 Other credits 28,481 Impax Generic Product sales, net 128,922 Rx Partner 5,159 Other Revenues 66 Impax Generic Division revenues, net 134,147 Impax Specialty Pharma, gross 84,133 Less: Chargebacks 9,828 Rebates 4,483 Product Returns 1,844 Other credits 17,722 Impax Specialty Pharma, net 50,256 Other Revenues — Impax Specialty Pharma, net 50,256 Total revenues 184,403 Gross profit 24,891 Net loss $ (98,431 ) Net loss per common share: Basic $ (1.37 ) Diluted $ (1.37 ) Weighted-average common shares outstanding: Basic 71,594,472 Diluted 71,594,472

BASIS OF PRESENTATION - Narrati

BASIS OF PRESENTATION - Narrative (Details)	May 04, 2018$ / sharesshares	Mar. 31, 2018segment$ / shares	May 03, 2018	Dec. 31, 2017$ / shares
Business Acquisition [Line Items]
Number of reportable segments | segment		2
Common stock, par value (in dollars per share)		$ 0.01		$ 0.01
Subsequent Event | Holdco | Common Class A
Business Acquisition [Line Items]
Conversion of stock, converted (in shares) | shares	1
Amneal | Subsequent Event
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	$ 0.01
Amneal | Subsequent Event | Common Class A | Holdco
Business Acquisition [Line Items]
Percentage of ownership before transaction			100.00%
Amneal | Subsequent Event | Common Class A | New Amneal
Business Acquisition [Line Items]
Percentage of voting interests acquired			25.00%
Amneal | Subsequent Event | Holdco | Common Class A
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	0.01
Amneal | Subsequent Event | Holdco | Common Class B
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	$ 0.01
Amneal | Subsequent Event | Amneal | New Amneal
Business Acquisition [Line Items]
Percentage of voting interests acquired	75.00%
Amneal | Subsequent Event | Amneal | Common Class B | Holdco
Business Acquisition [Line Items]
Percentage of ownership after transaction	100.00%

SUMMARY OF SIGNIFICANT ACCOUN42

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accumulated deficit	$ (503,004)		$ (372,445)
Total minimum lease payments			$ 28,100
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accumulated deficit		$ 400

REVENUE RECOGNITION - Narrative

REVENUE RECOGNITION - Narrative (Details)	3 Months Ended
	Mar. 31, 2018
Minimum
Principal Transaction Revenue [Line Items]
Cash discount, discount rate	2.00%
Cash discount, invoice terms	30 days
Maximum
Principal Transaction Revenue [Line Items]
Cash discount, discount rate	3.00%
Cash discount, invoice terms	90 days

FAIR VALUE MEASUREMENT AND FI44

FAIR VALUE MEASUREMENT AND FINANCIAL INSTRUMENTS - Schedule of Carrying Amounts and Fair Values (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Aug. 03, 2016
Assets
Deferred Compensation Plan asset	$ 42,594,000	$ 43,023,000
Liabilities
Term Loan Facility due August 2021, current portion, carrying amount	17,859,000	17,848,000
Term Loan Facility due August 2021, long-term portion, carrying amount	771,216,000	769,524,000
Deferred Compensation Plan liabilities	33,899,000	33,413,000
Contingent consideration, carrying amount	0	0
Contingent consideration, fair value	0	0
Contingent consideration, fair value	0	0
Teva transaction | Maximum
Liabilities
Maximum contingent consideration payments (up to)			$ 40,000,000
2% Convertible senior notes due June 2022
Liabilities
2% convertible senior notes due June 2022, carrying amount	600,000,000	600,000,000
2% convertible senior notes due June 2022, fair value	597,000,000	579,378,000
Term Loan
Liabilities
Term Loan Facility due August 2021, current portion, carrying amount	20,000,000	20,000,000
Term Loan Facility due August 2021, current portion, fair value	20,000,000	20,000,000
Term Loan Facility due August 2021, long-term portion, carrying amount	300,000,000	305,000,000
Term Loan Facility due August 2021, long-term portion, fair value	300,000,000	305,000,000
Quoted Prices in Active Markets (Level 1)
Assets
Deferred Compensation Plan asset	0	0
Liabilities
Deferred Compensation Plan liabilities	0	0
Contingent consideration, fair value	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	$ 597,000,000	$ 579,378,000
Interest rate, stated percentage	2.00%	2.00%
Quoted Prices in Active Markets (Level 1) | Term Loan
Liabilities
Term Loan Facility due August 2021, current portion, fair value	$ 0	$ 0
Term Loan Facility due August 2021, long-term portion, fair value	0	0
Significant Other Observable Inputs (Level 2)
Assets
Deferred Compensation Plan asset	42,594,000	43,023,000
Liabilities
Deferred Compensation Plan liabilities	33,899,000	33,413,000
Contingent consideration, fair value	0	0
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 Other Observable Inputs (Level 2) | Term Loan
Liabilities
Term Loan Facility due August 2021, current portion, fair value	20,000,000	20,000,000
Term Loan Facility due August 2021, long-term portion, fair value	300,000,000	305,000,000
Significant Unobservable Inputs (Level 3)
Assets
Deferred Compensation Plan asset	0	0
Liabilities
Deferred Compensation Plan liabilities	0	0
Contingent consideration, fair value	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
Significant Unobservable Inputs (Level 3) | Term Loan
Liabilities
Term Loan Facility due August 2021, current portion, fair value	0	0
Term Loan Facility due August 2021, long-term portion, fair value	$ 0	$ 0

ACCOUNTS RECEIVABLE - Compositi

ACCOUNTS RECEIVABLE - Composition of Accounts Receivable Net (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	$ 512,113,000			$ 634,059,000
Less: Rebate reserve	(112,019,000)			(181,611,000)
Less: Chargeback reserve	(100,516,000)			(136,891,000)
Less: Distribution services reserve	(16,545,000)			(11,037,000)
Less: Discount reserve	(10,801,000)			(14,344,000)
Less: Uncollectible accounts reserve	(45,859,000)			(49,423,000)
Accounts receivable, net	226,373,000			240,753,000
Receivable from Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	44,300,000			$ 44,300,000
Turing Pharmaceuticals AG
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross accounts receivable	44,300,000
Reserve for Turing receivable			$ 48,000,000
Reduction in the reserve resulting from payments received		$ 7,700,000
Change in reserve	$ 0

ACCOUNTS RECEIVABLE - Roll Forw

ACCOUNTS RECEIVABLE - Roll Forward of the Rebate Reserves Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Rebate reserve
Beginning balance	$ 181,611
Ending balance	112,019	$ 181,611
Rebate reserve
Rebate reserve
Beginning balance	181,611	293,816
Provision recorded during the period for Impax Generics rebates	104,339	642,447
Credits issued during the period for Impax Generics rebates	(173,931)	(754,652)
Ending balance	$ 112,019	$ 181,611

ACCOUNTS RECEIVABLE - Roll Fo47

ACCOUNTS RECEIVABLE - Roll Forward of the Chargeback Reserves Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Chargeback reserve
Beginning balance	$ 136,891
Ending balance	100,516	$ 136,891
Chargeback reserve
Chargeback reserve
Beginning balance	136,891	151,978
Provision recorded during the period	248,590	1,212,039
Credits issued during the period	(284,965)	(1,227,126)
Ending balance	$ 100,516	$ 136,891

INVENTORY - Net of Carrying Val

INVENTORY - Net of Carrying Value Reserves (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 65,275	$ 63,732
Work in process	12,510	3,046
Finished goods	94,272	104,187
Total inventory	172,057	170,965
Less: Non-current inventory	13,466	12,494
Total inventory - current	$ 158,591	$ 158,471

INVENTORY - Narrative (Details)

INVENTORY - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Inventory valuation reserves	$ 55	$ 71.6
Unapproved Inventory
Inventory [Line Items]
Unapproved product inventory, net	$ 15.7	$ 19.3

PROPERTY, PLANT AND EQUIPMENT -

PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Land	$ 3,500	$ 3,500
Buildings and improvements	94,608	96,775
Equipment	82,639	82,442
Office furniture and equipment	10,527	11,082
Construction-in-progress	46,990	46,622
Property, plant and equipment, gross	238,264	240,421
Less: Accumulated depreciation	(114,976)	(115,608)
Property, plant and equipment, net	$ 123,288	$ 124,813

PROPERTY, PLANT AND EQUIPMENT51

PROPERTY, PLANT AND EQUIPMENT - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 2.9	$ 7.8
Unpaid vendor invoices, excluded from cash flows	$ 0.6	$ 4.3

INTANGIBLE ASSETS AND GOODWIL52

INTANGIBLE ASSETS AND GOODWILL - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Marketed Product Rights
Gross Carrying Value, Beginning of Period	$ 430,009
Accumulated Amortization, Beginning of Period	(205,545)
Intangible Assets, Net, Beginning of Period	224,464
Amortization	(14,473)	$ (17,200)
Gross Carrying Value, End of Period	430,009
Accumulated Amortization, End of Period	(220,018)
Intangible Assets, Net, End of Period	209,991
IPR&D and Royalties
Non-amortized Value, Beginning of Period	38,003
Additions	1,000
Non-amortized Value, End of Period	39,003
Total Company
Intangible Assets, Net, Beginning of Period	262,467
Additions	1,000
Amortization	(14,473)	$ (17,200)
Intangible Assets, Net, End of Period	$ 248,994

INTANGIBLE ASSETS AND GOODWIL53

INTANGIBLE ASSETS AND GOODWILL - Narrative (Details)	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)product	Dec. 31, 2017USD ($)
Amortized intangible assets:
Amortization expense	$ 14,473,000	$ 17,200,000
Intangible asset impairment charges	0	$ 45,359,000
Goodwill	207,329,000		$ 207,329,000
Impax Generics
Amortized intangible assets:
Goodwill	147,600,000
Impax Specialty Pharma
Amortized intangible assets:
Goodwill	$ 59,700,000
Teva transaction
Amortized intangible assets:
Intangible assets, number of products impaired | product		3
Cost of revenues
Amortized intangible assets:
Intangible asset impairment charges		$ 39,300,000
IPR&D
Amortized intangible assets:
Intangible asset impairment charges		$ 6,100,000
Marketed Product Rights | Teva transaction
Amortized intangible assets:
Finite-lived intangible assets, number of products impaired | product		2
IPR&D | Teva transaction
Amortized intangible assets:
Indefinite-lived intangible assets, number of products impaired | product		1

ACCRUED EXPENSES - Schedule of

ACCRUED EXPENSES - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Aug. 18, 2016	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payroll-related expenses		$ 16,267	$ 38,415
Product returns		80,781	76,293
Accrued shelf stock		13,165	7,525
Government rebates		52,934	73,970
Accrued litigation settlements		51,900	4,900
Legal and professional fees		12,185	14,005
Estimated Teva and Allergan chargebacks and rebates		13,277	13,277
Accrued profit sharing and royalty expenses		11,713	8,373
Other		16,454	11,369
Total accrued expenses		268,676	$ 248,127
Teva transaction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated Teva and Allergan chargebacks and rebates		13,300
Acquired balances	$ 42,400
Chargeback and reserve payments		$ 29,100

ACCRUED EXPENSES - Return Reser

ACCRUED EXPENSES - Return Reserve Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 76,293
Ending balance	80,781	$ 76,293
Returns Reserve
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	76,293	72,888
Provision related to sales recorded in the period	19,709	47,709
Credits issued during the period	(15,221)	(44,304)
Ending balance	$ 80,781	$ 76,293

DEBT - Narrative (Details)

DEBT - Narrative (Details)	Feb. 28, 2017USD ($)	Aug. 03, 2016USD ($)	Jun. 30, 2015USD ($)day$ / shares	Mar. 31, 2018USD ($)$ / shares	Mar. 31, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2017USD ($)	Mar. 27, 2017	Mar. 26, 2017	Dec. 31, 2016USD ($)	Aug. 02, 2016USD ($)
Debt Instrument [Line Items]
Current portion of long-term debt, net				$ 17,859,000			$ 17,848,000
Long-term debt, net				771,216,000			769,524,000
Loss on debt extinguishment				0	$ 1,215,000
Convertible debt			$ 600,000,000
Carrying value of convertible debt				476,000,000			469,900,000
Conversion Option
Debt Instrument [Line Items]
Fair value of conversion option derivative liability			$ 167,000,000
Convertible Debt
Debt Instrument [Line Items]
Interest expense				9,200,000	8,700,000
Increase in accrued interest				3,000,000	3,000,000
Non-cash accretion				$ 6,200,000	5,700,000
Interest rate, stated percentage			2.00%
Conversion ratio			0.0157858	0.0157858
Exercise price (in dollars per share) | $ / shares			$ 63.35	$ 63.35
Number of trading days (at least) | day			20
Number of consecutive trading days | day			30
Percentage of stock price trigger			130.00%
Debt issuance costs			$ 18,700,000
Interest payable				$ 3,500,000			500,000
Convertible Debt | Conversion Circumstance 2
Debt Instrument [Line Items]
Number of trading days (at least) | day			5
Number of consecutive trading days | day			10
Percentage of stock price trigger			98.00%
Teva transaction
Debt Instrument [Line Items]
Cash		$ 196,400,000
Term Loan
Debt Instrument [Line Items]
Current portion of long-term debt, net				20,000,000			20,000,000
Long-term debt, net				300,000,000			$ 305,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity		$ 200,000,000		199,700,000							$ 100,000,000
Leverage ratio (not to exceed)								2.5	5
Interest coverage ratio (less than)								3
Debt issuance costs for lines of credit										$ 300,000
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Commitment fee percentage		0.50%
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Commitment fee percentage		0.375%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Change in margin		0.25%
Revolving Credit Facility | Term Loan
Debt Instrument [Line Items]
Borrowing capacity		$ 400,000,000
Interest expense				4,700,000	4,400,000
Increase in accrued interest				4,200,000	3,800,000
Non-cash accretion				500,000	600,000
Long-term debt				313,000,000
Current portion of long-term debt, net				17,900,000
Long-term debt, net				295,100,000
Principal payment				5,000,000
Outstanding principal				$ 320,000,000
Repayment of debt and accrued interest	$ 50,300,000
Repayment of debt principal	50,000,000
Interest payment	$ 300,000
Loss on debt extinguishment					1,200,000
Revolving Credit Facility | Term Loan | Teva transaction
Debt Instrument [Line Items]
Proceeds from issuance of debt		400,000,000
Payments of debt issuance costs					$ 800,000	$ 11,000,000
Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity		$ 12,500,000

STOCKHOLDERS' EQUITY - Narrativ

STOCKHOLDERS' EQUITY - Narrative (Details) $ / shares in Units, $ in Thousands	Jun. 30, 2015USD ($)$ / sharesshares	Mar. 31, 2018USD ($)shares$ / shares	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)$ / sharesshares
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		2,000,000		2,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)		0		0
Preferred stock, shares outstanding (in shares)		0		0
Common stock, shares authorized (in shares)		150,000,000		150,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.01		$ 0.01
Common stock, shares issued (in shares)		74,080,636		74,234,076
Common stock, shares outstanding (in shares)		73,836,907		73,990,347
Accumulated deficit | $		$ (503,004)		$ (372,445)
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Class of Stock [Line Items]
Accumulated deficit | $			$ 400
Convertible Debt
Class of Stock [Line Items]
Number of call options (in shares)		600,000
Consideration for call options | $		$ 147,000
Conversion ratio	0.0157858	0.0157858
Exercise price (in dollars per share) | $ / shares	$ 63.35	$ 63.35
Warrant
Class of Stock [Line Items]
Warrants to purchase common stock (in shares)	9,470,000	9,471,000
Proceeds from sale of warrants | $	$ 88,300
Exercise price of warrants (in dollars per share) | $ / shares	$ 81.277

STOCKHOLDERS' EQUITY - Common S

STOCKHOLDERS' EQUITY - Common Stock Reserved for Future Issuance (Details) - shares	Jun. 30, 2015	Mar. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Shares issued (in shares)		74,080,636	74,234,076
Total shares of common stock issued and reserved for issuance (in shares)		96,065,000
Warrant
Class of Stock [Line Items]
Stock options outstanding (in shares)		9,471,000
Warrants outstanding (in shares)		9,471,000
Warrant
Class of Stock [Line Items]
Conversion of Notes payable (in shares)	9,470,000	9,471,000
Employee Stock Option
Class of Stock [Line Items]
Stock options outstanding (in shares)		3,042,000
Warrants outstanding (in shares)		3,042,000

EARNINGS PER SHARE - Reconcilia

EARNINGS PER SHARE - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic Loss Per Common Share:
Net loss	$ (130,932)	$ (98,431)
Weighted-average common shares outstanding (in shares)	72,265,794	71,594,472
Basic loss per share (in dollars per share)	$ (1.81)	$ (1.37)
Diluted Loss Per Common Share:
Net loss	$ (130,932)	$ (98,431)
Add-back of interest expense on outstanding convertible notes payable, net of tax	0	0
Adjusted net loss	$ (130,932)	$ (98,431)
Weighted-average common shares outstanding (in shares)	72,265,794	71,594,472
Weighted-average incremental shares related to assumed exercise of warrants and stock options, vesting of non-vested shares and ESPP share issuance (in shares)	0	0
Weighted-average incremental shares assuming conversion of outstanding notes payable (in shares)	0	0
Diluted weighted-average common shares outstanding (in shares)	72,265,794	71,594,472
Diluted loss per share (in dollars per share)	$ (1.81)	$ (1.37)
Warrant
Diluted Loss Per Common Share:
Antidilutive securities (in shares)	9,470,000	9,470,000
Convertible Debt Securities
Diluted Loss Per Common Share:
Antidilutive securities (in shares)	9,470,000	9,470,000
Employee Stock Option
Diluted Loss Per Common Share:
Antidilutive securities (in shares)	3,040,000	3,340,000
Restricted Stock
Diluted Loss Per Common Share:
Antidilutive securities (in shares)	1,560,000	2,210,000

SHARE-BASED COMPENSATION - Narr

SHARE-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 27, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)		3,042,269		3,174,997
Weighted average contractual life		6 years 7 months 2 days
Weighted average remaining contractual life		5 years 8 months 12 days
Intrinsic value of options outstanding		$ 13,700
Intrinsic value of exercisable options		7,100
Unrecognized share-based compensation expense		$ 33,000
Period of recognition		1 year 6 months 7 days
Intrinsic value of options exercisable		$ 11,800	$ 0
Dividend yield		0.00%
President and CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding (in shares)		850,000
Options granted (in shares)	850,000
Amended and Restated 2002 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		18,050,000
Stock options outstanding (in shares)		2,192,269		2,324,997
Restricted stock awards outstanding (in shares)		1,560,684		1,861,489
Number of shares available for grant (in shares)		2,130,036
The 1999 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		5,000,000
Stock options outstanding (in shares)		0		0
Number of shares available for grant (in shares)		296,921
The ESPP Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)		1,499,596
Stock Options And Restricted Stock Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of awards		10 years
Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards intrinsic value		$ 30,400
Vested (in shares)		103,144
Fair value of restricted stock vested		$ 2,700	$ 2,300
Restricted Stock | Withheld for Minimum Withholding Tax Purposes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)		49,427
Vested (in dollars per share)		$ 20.39

SHARE-BASED COMPENSATION - Summ

SHARE-BASED COMPENSATION - Summary of Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Number of Shares Under Option
Outstanding at December 31, 2017 (in shares) | shares	3,174,997
Options exercised (in shares) | shares	(127,648)
Options forfeited (in shares) | shares	(5,080)
Outstanding at March 31, 2018 (in shares) | shares	3,042,269
Options exercisable at March 31, 2018 (in shares) | shares	1,875,982
Weighted- Average Exercise Price per Share
Outstanding at December 31, 2017 (in dollars per share) | $ / shares	$ 18.36
Options exercised ( in dollars per share) | $ / shares	9.28
Options forfeited (in dollars per share) | $ / shares	8.38
Outstanding at March 31, 2018 (in dollars per share) | $ / shares	18.76
Options exercisable at March 31, 2018 (in dollars per share) | $ / shares	$ 20.08

SHARE-BASED COMPENSATION - Su62

SHARE-BASED COMPENSATION - Summary of Non-vested Restricted Stock Awards (Details) - Restricted Stock Awards	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Number of Restricted Stock Awards
Non-vested at December 31, 2017 (in shares) | shares	1,861,489
Vested (in shares) | shares	(103,144)
Forfeited (in shares) | shares	(197,661)
Non-vested at March 31, 2018 (in shares) | shares	1,560,684
Weighted- Average Grant Date Fair Value
Non-vested at December 31, 2017 (in dollars per share) | $ / shares	$ 25.36
Vested (in dollars per share) | $ / shares	26.54
Forfeited (in dollars per share) | $ / shares	26.15
Non-vested at March 31, 2018 (in dollars per share) | $ / shares	$ 25.19

SHARE-BASED COMPENSATION - Shar

SHARE-BASED COMPENSATION - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 4,816	$ 6,957
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	520	1,584
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	3,196	1,423
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 1,100	$ 3,950

RESTRUCTURINGS - Narrative (Det

RESTRUCTURINGS - Narrative (Details) $ in Thousands	Feb. 06, 2018USD ($)	May 31, 2017	May 31, 2017position	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 30, 2017asset	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)position	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Mar. 31, 2018USD ($)position	Jan. 16, 2018USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				$ 547	$ 7,595			$ 7,595	$ 547	$ 7,595	$ 547
Program termination costs that were paid				7,245
Assets				1,220,898	1,351,300			1,351,300	1,220,898	1,351,300	1,220,898
Foreign currency translation adjustment				849			$ 0
Sale Of Middlesex, New Jersey Assets | Disposal Group, Held-for-sale, Not Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Impairment charge					3,300
Sale Of Middlesex, New Jersey Assets | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Disposal group consideration												$ 2,200
Sale Of Taiwan Facility | Disposal Group, Held-for-sale, Not Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Impairment charge					74,100
Cash received from divestiture of business	$ 16,500
Holdback receivable	2,000
Loss on sale of assets, primarily related to final working capital adjustments	1,200
Foreign currency translation adjustment	$ 800
Sale Of Taiwan Facility | Disposal Group, Held-for-sale, Not Discontinued Operations | Property, Plant and Equipment
Restructuring Cost and Reserve [Line Items]
Impairment charge					73,600
Middlesex, New Jersey Assets
Restructuring Cost and Reserve [Line Items]
Assets					5,600			5,600		5,600
Taiwan Facility
Restructuring Cost and Reserve [Line Items]
Useful life		2 years
Accelerated depreciation										9,100
Assets					91,700			91,700		91,700
Employee retention and severance payments
Restructuring Cost and Reserve [Line Items]
Restructuring reserve				338	7,386			7,386	338	7,386	$ 338
Program termination costs that were paid				7,073
Employee retention and severance payments | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Employee retention and severance cost expense				200			4,300
Manufacturing and Packaging Site
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position											215
Aggregate pre-tax charges				43,586					43,586		$ 43,586
Manufacturing and Packaging Site | Employee retention and severance payments
Restructuring Cost and Reserve [Line Items]
Aggregate pre-tax charges				12,752					12,752		$ 12,752
Consolidation and Improvement Plan Generic R&D
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position			31
Aggregate pre-tax charges					3,400			$ 3,400		3,400
Consolidation and Improvement Plan Generic R&D | Employee Termination Benefits
Restructuring Cost and Reserve [Line Items]
Program termination costs that were paid									$ 2,800
Technical Operations Group Reduction-in-force
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position								48
Technical Operations Group Reduction-in-force | Employee Termination Benefits
Restructuring Cost and Reserve [Line Items]
Aggregate pre-tax charges					$ 3,700			$ 3,700		$ 3,700
Program termination costs that were paid				1,700
Costs incurred				$ 0			$ 1,800
Tower | ANDA
Restructuring Cost and Reserve [Line Items]
Number of assets sold for approved non-strategic generic products | asset						29
Tower | NDA
Restructuring Cost and Reserve [Line Items]
Number of assets sold for approved non-strategic generic products | asset						1

RESTRUCTURINGS - Summary of Tot

RESTRUCTURINGS - Summary of Total Estimated Charges (Details) - Manufacturing and Packaging Site $ in Thousands	Mar. 31, 2018USD ($)
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	$ 43,586
Employee retention and severance payments
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	12,752
Technical transfer of products
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	9,716
Asset impairment and accelerated depreciation charges
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	20,900
Facilities lease terminations and asset retirement obligations
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	209
Legal and professional fees
Restructuring Cost and Reserve [Line Items]
Total estimated restructuring charges	$ 9

RESTRUCTURINGS - Summary of Cha

RESTRUCTURINGS - Summary of Charges to General and Administrative Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Total	$ 197	$ 4,322
Employee retention and severance payments
Restructuring Cost and Reserve [Line Items]
Total	25	1,480
Technical transfer of products
Restructuring Cost and Reserve [Line Items]
Total	172	1,188
Asset impairment and accelerated depreciation charges
Restructuring Cost and Reserve [Line Items]
Total	0	1,561
Facilities lease terminations and asset retirement obligations
Restructuring Cost and Reserve [Line Items]
Total	$ 0	$ 93

RESTRUCTURINGS - Summary of Res

RESTRUCTURINGS - Summary of Reserve Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, Beginning of Period	$ 7,595
Expensed / Accrued Expense	197	$ 4,322
Cash Payments	(7,245)
Non-Cash Items	0
Restructuring reserve, End of Period	547
Employee retention and severance payments
Restructuring Reserve [Roll Forward]
Restructuring reserve, Beginning of Period	7,386
Expensed / Accrued Expense	25	1,480
Cash Payments	(7,073)
Non-Cash Items	0
Restructuring reserve, End of Period	338
Technical transfer of products
Restructuring Reserve [Roll Forward]
Restructuring reserve, Beginning of Period	0
Expensed / Accrued Expense	172	$ 1,188
Cash Payments	(172)
Non-Cash Items	0
Restructuring reserve, End of Period	0
Legal and professional fees
Restructuring Reserve [Roll Forward]
Restructuring reserve, Beginning of Period	209
Expensed / Accrued Expense	0
Cash Payments	0
Non-Cash Items	0
Restructuring reserve, End of Period	$ 209

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Feb. 28, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Tax expense (benefit)	$ (7,290)	$ 30,901
Effective income tax rate reconciliation, percent	5.30%	(45.80%)
Valuation allowance	$ 208,500			$ 185,900
Additional valuation allowance	$ 22,600
Number of years in cumulative loss	3 years
Capital Loss Carryforward | Disposal Group, Held-for-sale, Not Discontinued Operations | Sale Of Taiwan Facility
Operating Loss Carryforwards [Line Items]
Loss on sale of assets			$ 20,700

ALLIANCE AND COLLABORATION AG69

ALLIANCE AND COLLABORATION AGREEMENTS - Narrative (Details)	Jun. 30, 2016USD ($)	Aug. 31, 2013USD ($)	Jun. 30, 2012USD ($)product	Mar. 31, 2018USD ($)product	Mar. 31, 2016USD ($)	Dec. 31, 2015product	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Profit share payable				$ 11,713,000			$ 8,373,000
Teva
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum achievement payments		$ 3,500,000
Milestone payment					$ 3,500,000
Products Approved
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of products | product				4
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]
Profit share payable				100,000				$ 800,000
Tolmar Incorporated
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Profit share payable				600,000				900,000
Number of products | product			11
Number of products with terminated development efforts | product						1
Tolmar Incorporated | Up-front Payment Arrangement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront payment			$ 21,000,000
Tolmar Incorporated | Milestone Payments
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum achievement payments			$ 25,000,000
Achievement payments made				20,000,000
Regulatory milestone event amount				12,000,000
Commercialization event amount				$ 5,000,000
Tolmar Incorporated | Products Approved
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of products | product			10
Teva Pharmaceutical Industries Limited
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Service agreement term				10 years
Astra Zeneca
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Reduced royalty amounts	$ 30,000,000
Royalty payable				$ 2,200,000				$ 3,300,000
IND-enabling Animal Studies for New Development Candidate | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				12 months
IND-enabling Animal Studies for New Development Candidate | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				18 months
Phase 1 Trials | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				1 year
Phase 1 Trials | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				2 years
Phase 2 Trials | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				1 year
Phase 2 Trials | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				3 years
Phase 3 Trials | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				2 years
Phase 3 Trials | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				4 years
Bioequivalence Studies | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				3 months
Bioequivalence Studies | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				1 year
Preparation And Submission Of Regulatory Filings | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				6 months
Preparation And Submission Of Regulatory Filings | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				12 months
Acceptance Of Regulatory Filings For Substantive Review
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				2 months
Potential Marketing Approval One | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				1 year
Potential Marketing Approval One | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				3 years
Potential Marketing Approval Two | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				1 year
Potential Marketing Approval Two | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Completion period				3 years

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
Open purchase order commitments	$ 103.5
Purchase commitment period (less than)	1 year

LEGAL AND REGULATORY MATTERS -

LEGAL AND REGULATORY MATTERS - Narrative (Details) $ in Millions

Jan. 19, 2018company

Jan. 27, 2017complaint

May 02, 2016USD ($)

Mar. 31, 2018USD ($)

Mar. 31, 2018

Apr. 30, 2017complaint

Apr. 30, 2015complaint

Apr. 30, 2017complaint

Jan. 31, 2016complaint

Mar. 05, 2018patent

Apr. 06, 2017drug

Feb. 15, 2017litigation

Loss Contingencies [Line Items]

Period to file suit for patent infringement

45 days

Stay period for approval of abbreviated new drug application

30 months

Biogen MA Inc. vs Impax Laboratories, Inc.

Loss Contingencies [Line Items]

Alleged infringement, number of additional patents | patent

2

Solodyn

Loss Contingencies [Line Items]

Number of complaints

18

Total settlement amount | $

$ 84.5

Opana ER

Loss Contingencies [Line Items]

Number of complaints

14

Generic Drug Pricing Class Action

Loss Contingencies [Line Items]

Number of complaints

3

22

Generic Digoxin and Doxycycline Antitrust Litigation

Loss Contingencies [Line Items]

Number of complaints

2

Number of generic drugs included in consolidation of civil actions | drug

18

Number of companies complaint filed against | company

35

Turing Pharmaceuticals AG

Loss Contingencies [Line Items]

Chargebacks not reimbursed for (more than) | $

$ 40.9

Teva

Loss Contingencies [Line Items]

Number of litigations | litigation

2

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)segmentproduct	Dec. 31, 2017USD ($)
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 other branded products | product	4
Assets | $	$ 1,220,898	$ 1,351,300
Taiwan Facility
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets | $	$ 0	$ 22,900

SEGMENT INFORMATION - Segment I

SEGMENT INFORMATION - Segment Information Reconciled to Consolidated Financial Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues, net	$ 142,355	$ 184,403
Cost of revenues	112,075	120,232
Cost of revenues impairment charges	0	39,280
Selling, general and administrative	57,323	47,055
Research and development	12,296	22,489
In-process research and development impairment charges	0	6,079
Litigation, settlements and related charges	85,537	1,072
(Loss) income before income taxes	(138,222)	(67,530)
Corporate and Other
Segment Reporting Information [Line Items]
Revenues, net	0	0
Cost of revenues	0	0
Cost of revenues impairment charges		0
Selling, general and administrative	32,147	24,257
Research and development	0	0
In-process research and development impairment charges		0
Litigation, settlements and related charges	0	0
(Loss) income before income taxes	(45,493)	(39,983)
Impax Generics
Segment Reporting Information [Line Items]
Revenues, net	83,141	134,147
Impax Generics | Operating Segments
Segment Reporting Information [Line Items]
Revenues, net	83,141	134,147
Cost of revenues	95,037	103,335
Cost of revenues impairment charges		39,280
Selling, general and administrative	7,556	6,468
Research and development	9,616	17,396
In-process research and development impairment charges		6,079
Litigation, settlements and related charges	84,597	368
(Loss) income before income taxes	(113,665)	(38,779)
Impax Specialty Pharma
Segment Reporting Information [Line Items]
Revenues, net	59,214	50,256
Impax Specialty Pharma | Operating Segments
Segment Reporting Information [Line Items]
Revenues, net	59,214	50,256
Cost of revenues	17,038	16,897
Cost of revenues impairment charges		0
Selling, general and administrative	17,620	16,330
Research and development	2,680	5,093
In-process research and development impairment charges		0
Litigation, settlements and related charges	940	704
(Loss) income before income taxes	$ 20,936	$ 11,232

SEGMENT INFORMATION - Schedule

SEGMENT INFORMATION - Schedule of Product Line Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Product Information [Line Items]
Total revenues	$ 142,355	$ 184,403
Impax Specialty Pharma
Product Information [Line Items]
Total revenues	59,214	50,256
Impax Specialty Pharma | Rytary® family
Product Information [Line Items]
Total revenues	$ 26,508
Percentage of revenue	19.00%
Impax Specialty Pharma | Albenza family
Product Information [Line Items]
Total revenues	$ 13,607
Percentage of revenue	10.00%
Impax Specialty Pharma | Oxymorphone HCI ER family
Product Information [Line Items]
Total revenues	$ 13,387	$ 18,970
Percentage of revenue	9.00%	10.00%
Impax Specialty Pharma | Zomig® family
Product Information [Line Items]
Total revenues	$ 10,478
Percentage of revenue	7.00%
Impax Specialty Pharma | Budesonide family
Product Information [Line Items]
Total revenues		$ 15,827
Percentage of revenue		9.00%
Impax Generics
Product Information [Line Items]
Total revenues	$ 83,141	$ 134,147
Impax Generics | Rytary® family
Product Information [Line Items]
Total revenues		$ 19,905
Percentage of revenue		11.00%
Impax Generics | Epinephrine Auto-Injector family (generic Adrenaclick®)
Product Information [Line Items]
Total revenues	$ 14,783	$ 20,318
Percentage of revenue	10.00%	11.00%
Impax Generics | Amphetamine Salts ER (CII) family (generic Adderall®)
Product Information [Line Items]
Total revenues		$ 12,173
Percentage of revenue		7.00%

SUPPLEMENTARY FINANCIAL INFOR75

SUPPLEMENTARY FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Less:
Total revenues	$ 142,355	$ 184,403
Gross Profit	30,280	24,891
Net Loss	$ (130,932)	$ (98,431)
Net loss per common share:
Basic (in dollars per share)	$ (1.81)	$ (1.37)
Diluted (in dollars per share)	$ (1.81)	$ (1.37)
Weighted-average common shares outstanding:
Basic (in shares)	72,265,794	71,594,472
Diluted (in shares)	72,265,794	71,594,472
Chargebacks
Less:
Sales Allowances	$ 248,590		$ 1,212,039
Rebates
Less:
Sales Allowances	104,339		$ 642,447
Impax Generics
Revenue:
Impax sales, gross	474,043	$ 630,672
Less:
Product Returns	16,174	9,733
Impax product sales, net	82,160	128,922
Total revenues	83,141	134,147
Impax Generics | Rx Partner
Less:
Other revenues	909	5,159
Impax Generics | Other Revenues
Less:
Other revenues	72	66
Impax Generics | Chargebacks
Less:
Sales Allowances	240,041	298,744
Impax Generics | Rebates
Less:
Sales Allowances	104,339	164,792
Impax Generics | Other credits
Less:
Sales Allowances	31,329	28,481
Impax Specialty Pharma
Revenue:
Impax sales, gross	97,215	84,133
Less:
Product Returns	3,535	1,844
Impax product sales, net		50,256
Total revenues	59,214	50,256
Impax Specialty Pharma | Other Revenues
Less:
Other revenues		0
Impax Specialty Pharma | Chargebacks
Less:
Sales Allowances	8,548	9,828
Impax Specialty Pharma | Rebates
Less:
Sales Allowances	5,601	4,483
Impax Specialty Pharma | Other credits
Less:
Sales Allowances	$ 20,317	$ 17,722

SUBSEQUENT EVENTS - Narrative (

SUBSEQUENT EVENTS - Narrative (Details)	May 04, 2018shares	May 03, 2018shares	Jun. 30, 2015	Mar. 31, 2018
Convertible Debt
Subsequent Event [Line Items]
Interest rate, stated percentage			2.00%
Conversion ratio			0.0157858	0.0157858
Subsequent Event
Subsequent Event [Line Items]
Outstanding stock options issued (in shares)		3,000,000
Subsequent Event | Convertible Debt
Subsequent Event [Line Items]
Interest rate, stated percentage	2.00%
Conversion ratio	0.0157853
Subsequent Event | Restricted Stock Awards
Subsequent Event [Line Items]
Common stock, unvested restricted stock awards issued and outstanding (in shares)		1,300,000
Subsequent Event | Amneal Pharmaceuticals, Inc. | Common Class A
Subsequent Event [Line Items]
Conversion of stock, converted (in shares)	1