Composition of Certain Financial Statement Items (Schedule of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Accrued payroll and employee-related expenses	$ 16,440	$ 22,890
Accrued clinical study expense	2,757	2,723
Accrued interest	2,576	1,016
Deferred rent	1,438	1,443
Accrued royalties	1,304	1,313
Accrued legal costs	1,180	847
Accrued sales and income taxes	935	1,208
Contingent consideration	200	279
Other accrued expenses	5,324	4,350
Total accrued liabilities	32,154	36,069
Less: long-term portion	(1,680)	(1,688)
Accrued liabilities, current portion	$ 30,474	$ 34,381