CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income (loss)	$ 12,776	$ (53,400)
Adjustments for non-cash items:
Depreciation and amortization	53,816	52,691
Accretion of debt discount and debt issuance costs	10,808	9,411
Loss on prepayment of Senior Notes		5,364
Provision for inventory obsolescence	218	2,110
Gain on disposal of property and equipment	(134)	(275)
Stock-based compensation	7,504	6,959
Change in fair value of contingent consideration	(462)	(6,176)
Other	39	264
Changes in assets and liabilities:
Accounts receivable	30,333	23,881
Inventories	7,847	490
Prepaid and other assets	(35,740)	173
Accounts payable and other accrued liabilities	(44,322)	(9,135)
Accrued rebates, returns and discounts	(55,656)	8,470
Interest payable	(938)	(2,716)
Income taxes payable	(126)
Net cash (used in) provided by operating activities	(14,037)	38,111
Investing Activities
Purchases of property and equipment	(772)	(504)
Proceeds from disposal of property and equipment	145	280
Purchases of marketable securities		(2,391)
Proceeds from sale of other assets	80
Maturities of marketable securities	1,200	58,281
Net cash provided by investing activities	653	55,666
Financing Activities
Payment of contingent consideration liability	(184)	(1,293)
Repayment of Senior Notes	(57,500)	(100,000)
Fees for early repayment and modifications of Senior Notes		(4,000)
Proceeds from issuance of common stock	1,684	7,242
Shares withheld for payment of employee's withholding tax liability	(267)	(210)
Net cash (used in) financing activities	(56,267)	(98,261)
Net (decrease) in cash and cash equivalents	(69,651)	(4,484)
Cash and cash equivalents at beginning of year	126,884	117,709
Cash and cash equivalents at end of period	57,233	113,225
Supplemental Disclosure of Cash Flow Information
Net cash paid for income taxes	166	121
Cash paid for interest	25,149	30,187
Capital expenditures incurred but not yet paid	$ 260	$ 130