Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities
Net Income	$ 6,094	$ 15,494	$ (1,076)
Adjustments to reconcile net income/(loss) to net cash and cash equivalents provided by operating activities:
Stock-based compensation	9,217	6,782	6,090
Deferred taxes	(9,134)	(5,180)	3,560
Depreciation and amortization	44,612	33,742	27,928
Acquired product rights and in-process research and development ("IPR&D")	2,324	1,335	0
Non-cash interest relating to convertible notes and loan cost amortization	7,024	8,465	7,666
Loss on repurchase of Convertible notes	0	468	0
Intangible asset impairment charge	75	0	903
Changes in operating assets and liabilities:
Accounts receivable, net	(7,287)	(4,743)	(12,893)
Inventories, net	(7,660)	(379)	5,356
Prepaid expenses and other current assets	403	(1,142)	(17)
Accounts payable	5,039	3,466	3
Accrued royalties	(3,372)	(3,708)	(417)
Current income taxes, net	(6,098)	6,184	(3,560)
Accrued government rebates	(73)	1,044	2,039
Returned goods reserve	4,043	4,278	2,518
Accrued expenses, accrued compensation, and other	424	968	1,319
Net Cash and Cash Equivalents Provided by Operating Activities	45,631	67,074	39,419
Cash Flows From Investing Activities
Acquisition of WellSpring Pharma Services Inc., net of cash acquired	0	(16,467)	0
Acquisition of product rights, IPR&D, and other related assets	(20,914)	(5,169)	(97,624)
Acquisition of property and equipment, net	(6,635)	(5,743)	(10,369)
Net Cash and Cash Equivalents Used in Investing Activities	(27,549)	(27,379)	(107,993)
Cash Flows From Financing Activities
Payment of debt issuance and convertible debt repurchase costs	0	(1,572)	(2,737)
Payments on Term loan agreement	(2,707)	(2,813)	0
Borrowings under Term loan agreement	0	0	75,000
Borrowings under Delayed Draw Term Loan Agreement	118,000	0	0
Proceeds from stock option exercises and ESPP purchases	5,738	2,978	353
Repayment of Convertible Notes	(118,750)	(26,125)	0
Unwinding of portion of call option overlay, net	0	375	0
Treasury stock purchases for restricted stock vestings	(1,031)	(659)	(259)
Net Cash and Cash Equivalents Provided/(Used in) by Financing Activities	1,250	(27,816)	72,357
Net Change in Cash and Cash Equivalents	19,332	11,879	3,783
Cash, cash equivalents, and restricted cash, beginning of period	48,029	36,150	32,367
Cash, cash equivalents, and restricted cash, end of period	67,361	48,029	36,150
Reconciliation of cash, cash equivalents, and restricted cash, beginning of period
Cash and cash equivalents	43,008	31,144	27,365
Restricted cash	5,021	5,006	5,002
Cash, cash equivalents, and restricted cash, beginning of period	48,029	36,150	32,367
Reconciliation of cash, cash equivalents, and restricted cash, end of period
Cash and cash equivalents	62,332	43,008	31,144
Restricted cash	5,029	5,021	5,006
Cash, cash equivalents, and restricted cash, end of period	67,361	48,029	36,150
Supplemental disclosure for cash flow information:
Cash paid for interest, net of amounts capitalized	6,092	6,285	3,759
Cash paid for income taxes	10,033	6,397	17,786
Supplemental non-cash investing and financing activities:
Acquisition of marketing and distribution rights included in accounts payable	500	0	0
Property and equipment purchased and included in accounts payable	$ 723	$ 521	$ 485