Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2017
Income Taxes [Line Items]
Amount expected to be utilized of tax credit carry forwards expiring in the and beyond the stated year	$ 1,200
Valuation allowance	23,072		$ 20,178
Unrecognized tax benefits, impact on effective tax rate	8,300	$ 500	2,800
Accrued interest and penalties	300	100	$ 100
Increase (decrease) in income tax expense	200	$ (100)
Unrecognized tax benefits, gross	100
Foreign Countries
Income Taxes [Line Items]
Valuation allowance	21,400
Foreign Countries
Income Taxes [Line Items]
Net operating loss carryforwards, foreign	27,700
California enterprise zone
Income Taxes [Line Items]
California enterprise zone tax credits	2,900
California enterprise zone | California Enterprise Zone
Income Taxes [Line Items]
Valuation allowance	$ 1,700