Income Taxes - Significant Components of Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Net operating loss and credit carryforwards	$ 8,356	$ 11,067
Stock-based compensation expense	3,647	4,273
Accounts receivable allowances	464	307
Accrued expenses	3,185	2,126
Other	180	182
Gross deferred tax asset	15,832	17,955
Less: valuation allowance	(797)	(602)
Total net deferred tax asset	15,035	17,353
Deferred tax liability
Deferred operations	(2,787)	(3,850)
Foreign operations	(135)	(133)
Depreciation and amortization	(2,943)	(1,536)
Other	(90)	(24)
Total deferred tax liability	(5,955)	(5,543)
Net deferred tax assets	$ 9,080	$ 11,810

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards and deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

No definition available.