CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities
Net income (loss)	$ 61,046	$ (69,392)
Adjustments for non-cash items:
Depreciation and amortization	80,729	79,031
Accretion of debt discount and debt issuance costs	16,298	14,249
Loss on prepayment of Senior Notes	0	5,364
Provision for inventory obsolescence	244	2,345
Gain on disposal of property and equipment	659	(275)
Stock-based compensation	10,275	9,922
Change in fair value of contingent consideration	(552)	(7,517)
Other	34	244
Changes in assets and liabilities:
Accounts receivable	28,570	24,864
Receivables from collaborative partners	0	27
Inventories	8,543	272
Prepaid and other assets	(63,039)	(4,428)
Accounts payable and other accrued liabilities	(28,071)	(20,648)
Accrued rebates, returns and discounts	(54,915)	5,463
Interest payable	(2,960)	(4,616)
Income taxes payable	(126)	0
Net cash provided by operating activities	56,735	34,905
Investing Activities
Purchases of property and equipment	(3,987)	(563)
Proceeds from disposal of property and equipment	145	281
Proceeds from sale of other assets	80	0
Investment in convertible instrument	(3,000)	0
Purchases of marketable securities	0	(7,074)
Maturities of marketable securities	1,200	60,681
Net cash (used in) investing activities	(5,562)	53,325
Financing Activities
Payment of contingent consideration liability	(184)	(1,673)
Repayment of Senior Notes	(57,500)	(100,000)
Fees for early repayment and modifications of Senior Notes	0	(4,000)
Proceeds from issuance of common stock	1,852	7,529
Shares withheld for payment of employee's withholding tax liability	(321)	(210)
Net cash (used in) financing activities	(56,153)	(98,354)
Net (decrease) in cash and cash equivalents	(4,980)	(10,124)
Cash and cash equivalents at beginning of year	126,884	117,709
Cash and cash equivalents at end of period	121,904	107,585
Supplemental Disclosure of Cash Flow Information
Net cash paid for income taxes	4,871	121
Cash paid for interest	38,811	44,832
Capital expenditures incurred but not yet paid	$ 30	$ 87