CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating Activities
Net (loss) income	$ (27,906)	$ 12,776
Adjustments for non-cash items:
Depreciation and amortization	51,503	53,816
Accretion of debt discount and debt issuance costs	12,220	10,808
Provision for inventory obsolescence	196	218
Gain on disposal of property and equipment	6	(134)
Stock-based compensation	5,336	7,504
Change in fair value of contingent consideration	(85)	(462)
Other	3,144	39
Changes in assets and liabilities:
Accounts receivable	2,900	30,333
Inventories	195	7,847
Prepaid and other assets	30,492	(35,740)
Accounts payable and other accrued liabilities	(14,890)	(44,322)
Accrued rebates, returns and discounts	(11,951)	(55,656)
Interest payable	(2,451)	(938)
Income taxes payable	0	(126)
Net cash provided by (used in) operating activities	48,709	(14,037)
Investing Activities
Purchases of property and equipment	(621)	(772)
Proceeds from disposal of property and equipment	0	145
Proceeds from sale of other assets	0	80
Purchases of marketable securities	(7,864)	0
Maturities of marketable securities	750	1,200
Net cash (used in) provided by investing activities	(7,735)	653
Financing Activities
Payment of contingent consideration liability	0	(184)
Repayment of Senior Notes	(80,000)	(57,500)
Fees for modification of Senior Notes	(3,249)	0
Proceeds from issuance of common stock	183	1,684
Shares withheld for payment of employee's withholding tax liability	(509)	(267)
Net cash (used in) financing activities	(83,575)	(56,267)
Net (decrease) in cash and cash equivalents	(42,601)	(69,651)
Cash and cash equivalents at beginning of year	110,949	126,884
Cash and cash equivalents at end of year	68,348	57,233
Supplemental Disclosure of Cash Flow Information
Net cash paid for income taxes	420	166
Cash paid for interest	21,571	25,149
Capital expenditures incurred but not yet paid	$ 287	$ 260