Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets:
Allowance for uncollectible accounts receivable	$ 693	$ 606
Accrued compensation expense	9,244	7,414
Inventory differences	2,207	1,269
Net operating loss carryforwards	21,187	20,226
Deferred revenue	552	46
Stock-based compensation expense	4,672	2,833
Operating lease assets	16,838
Federal R&D Tax Credits	1,376
Other	6,189	9,243
Total deferred income tax assets	62,958	41,637
Deferred income tax liabilities:
Prepaid expenses	(1,128)	(1,142)
Property and equipment	(21,242)	(20,045)
Intangible assets	(53,933)	(58,883)
Foreign withholding tax	(5,240)	(5,590)
Operating lease liabilities	(15,847)
Other	(2,372)	(4,350)
Total deferred income tax liabilities	(99,762)	(90,010)
Valuation allowance	(4,644)	(4,989)
Net deferred income tax liabilities	(41,448)	(53,362)
Reported as:
Deferred income tax assets	3,788	3,001
Deferred income tax liabilities	(45,236)	(56,363)
Net deferred income tax liabilities	$ (41,448)	$ (53,362)