Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Allowance for credit losses on trade receivables	$ 1,198	$ 693
Accrued compensation expense	9,694	9,244
Inventory differences	3,161	2,207
Net operating loss carryforwards	18,622	21,187
Deferred revenue	617	552
Stock-based compensation expense	7,360	4,672
Operating lease assets	15,182	16,838
Federal R&D tax credit	3,607	1,376
Other	13,993	6,189
Total deferred income tax assets	73,434	62,958
Deferred income tax liabilities:
Prepaid expenses	(1,078)	(1,128)
Property and equipment	(20,671)	(21,242)
Intangible assets	(47,178)	(53,933)
Foreign withholding tax	(5,358)	(5,240)
Operating lease liabilities	(13,855)	(15,847)
Other	(3,796)	(2,372)
Total deferred income tax liabilities	(91,936)	(99,762)
Valuation allowance	(10,213)	(4,644)
Net deferred income tax liabilities	(28,715)	(41,448)
Reported as:
Deferred income tax assets	4,597	3,788
Deferred income tax liabilities	(33,312)	(45,236)
Net deferred income tax liabilities	$ (28,715)	$ (41,448)