Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Allowance for uncollectible accounts receivable	$ 645	$ 531
Accrued compensation expense	6,203	5,534
Inventory differences	1,065	2,043
Net operating loss carryforwards	27,742	11,434
Deferred revenue	73	118
Stock-based compensation expense	2,738	2,532
Federal research and development credit carryforward	3,524	2,355
Foreign tax credits	364	600
Other	6,984	5,754
Total deferred income tax assets	49,338	30,901
Deferred income tax liabilities:
Prepaid expenses	(782)	(841)
Property and equipment	(25,108)	(24,467)
Intangible assets	(35,773)	(6,495)
Other	(1,480)	(1,077)
Total deferred income tax liabilities	(63,143)	(32,880)
Valuation allowance	(3,786)	(1,981)
Net deferred income tax liabilities	(17,591)	(3,960)
Reported as:
Deferred income tax assets - Current	8,219	7,025
Deferred income tax assets - Long-term	171	0
Deferred income tax liabilities - Current	0	0
Deferred income tax liabilities - Long-term	(25,981)	(10,985)
Net deferred income tax liabilities	$ (17,591)	$ (3,960)