Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Cash Flows From Operating Activities
Net income	$ 2,777	$ 2,681	$ 5,027	$ 3,833
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Stock-based compensation			3,159	3,193
Deferred taxes			(987)	(1,706)
Depreciation and amortization	8,313	7,101	16,508	13,807
Acquired in-process research and development ("IPR&D")			1,335	0
Non-cash interest relating to convertible notes and loan cost amortization			4,237	3,790
Changes in operating assets and liabilities:
Accounts receivable, net			2,673	(9,618)
Inventories, net			171	776
Prepaid expenses and other current assets			1,106	836
Accounts payable			4,571	(345)
Accrued royalties			(3,945)	(701)
Accrued compensation and related expenses			(896)	(404)
Current income taxes, net			(572)	(6,389)
Accrued government rebates			(2,674)	(2,357)
Returned goods reserve			1,490	1,802
Accrued expenses and other			320	13
Net Cash and Cash Equivalents Provided by Operating Activities			31,523	6,530
Cash Flows From Investing Activities
Acquisition of product rights, IPR&D, and other related assets			(5,169)	(50,956)
Acquisition of property and equipment, net			(3,364)	(4,442)
Net Cash and Cash Equivalents Used in Investing Activities			(8,533)	(55,398)
Cash Flows From Financing Activities
Payment of debt issuance costs			(153)	0
Payments on term loan agreement			(938)	0
Net borrowings under line of credit agreement			0	30,000
Proceeds from stock option exercises			2,611	131
Treasury stock purchases for restricted stock vestings			(659)	(259)
Net Cash and Cash Equivalents Provided by Financing Activities			861	29,872
Change in Cash, Cash Equivalents, and Restricted Cash			23,851	(18,996)
Cash, cash equivalents, and restricted cash, beginning of period			36,150	32,367	$ 32,367
Cash, cash equivalents, and restricted cash, end of period	60,001	13,371	60,001	13,371	36,150
Reconciliation of cash, cash equivalents, and restricted cash, beginning of period
Cash and cash equivalents			31,144	27,365	27,365
Restricted cash			5,006	5,002	5,002
Cash, cash equivalents, and restricted cash, beginning of period			36,150	32,367	32,367
Reconciliation of cash, cash equivalents, and restricted cash, end of period
Cash and cash equivalents	54,994	8,369	54,994	8,369	31,144
Restricted cash	5,007	5,002	5,007	5,002	5,006
Cash, cash equivalents, and restricted cash, end of period	$ 60,001	$ 13,371	60,001	13,371	$ 36,150
Supplemental disclosure for cash flow information:
Cash paid for interest, net of amounts capitalized			3,179	2,097
Cash paid for income taxes			2,895	9,882
Supplemental non-cash investing and financing activities:
Property and equipment purchased and included in accounts payable			$ 233	$ 109