Income Taxes (Details 4) $ in Thousands, € in Millions	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Apr. 30, 2014 EUR (€)	Apr. 30, 2014 USD ($)
Deferred tax assets:
Net operating loss carryforward	$ 8,616	$ 7,877
State income taxes	300	270
Inventory capitalization and reserve	5,365	6,843
Deferred revenue	584	864
Accrued payroll and benefits	1,793	1,571
Share-based compensation	10,125	8,437
Research and development credits	13,071	9,863
Alternative minimum tax	529	447
Accrued professional fees	987	568
Product return allowance	1,545	1,221
Accrued chargebacks	5,910	4,792
Bad debt reserve	253	67
Intangibles	3,370	3,861
Accrued for workers’ compensation insurance	1,035	864
Total deferred tax assets	53,483	47,545
Deferred tax liabilities:
Depreciation/amortization	15,065	15,649
Intangibles	5,430	4,753
Federal impact of state deferred taxes	3,380	2,910
Other	1,241	937
Total deferred tax liabilities	25,116	24,249
Valuation allowance	(923)	(3,862)	€ (3.2)	$ (4,400)
Net deferred tax assets	$ 27,444	$ 19,434