Income Taxes - Summary of Net Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Provision for excess and obsolete inventory	$ 2,003	$ 2,710
Depreciation and amortization	0	1,426
Interest expense limitation	5,562	2,769
Net operating loss and tax credit carryforwards	95,258	86,385
Share-based compensation	1,226	1,218
Right-of-use-asset	650
Unrecognized tax benefits	1,288	1,163
Deferred tax assets	105,987	95,671
Deferred tax liabilities:
Operating lease liability	(650)
Purchased intangible assets	(3,623)	(4,485)
Depreciation and amortization	(1,742)	0
Accrued expenses	(219)	(1,799)
Deferred tax liabilities	(6,234)	(6,284)
Valuation allowance	(103,702)	(93,844)
Net deferred tax liabilities	$ (3,949)	$ (4,457)