Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Stock compensation expense	$ 2,624	$ 3,394
Goodwill	2,235	2,673
Royalty accruals	353	992
Intangible assets	967	0
Bad debt allowance	389	333
Inter-company interest expense accrual	629	476
Other	399	637
Net operating loss carryforwards	5,485	1,576
Credit carry-forwards	584	359
Inventory reserve	318	0
Total deferred tax assets	13,983	10,440
Deferred tax liabilities:
Depreciation	(460)	(777)
Intangible assets	0	(294)
Other	(344)	(306)
Total deferred tax liabilities	(804)	(1,377)
Net deferred tax asset before valuation allowance	13,179	9,063
Valuation allowances for deferred tax assets	(13,179)	(7,832)	$ (2,006)	$ (1,833)
Net deferred tax asset	$ 0	$ 1,231