Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. Federal tax expense at statutory rates	$ (310)	$ 2,231
Increase (decrease) resulting from:
Tax credits	(170)	130
State income tax	25	14
International operations	183	20
Incentive stock options	(23)	(66)
Valuation allowance	311	(2,121)
Expiration of state net operating loss carryforwards	77	236
Other, net	48	26
Total Income tax expense	$ 141	$ 470
U.S. Federal tax expense at statutory rates	34.00%	34.00%
Increase (decrease) resulting from:
Tax credits	18.60%	2.00%
State income tax	(2.70%)	0.20%
International operations	(20.10%)	0.30%
Incentive stock options	2.60%	(1.00%)
Valuation allowance	(34.20%)	(32.40%)
Expiration of state net operating loss carryforwards	(8.50%)	3.60%
Other, net	(5.40%)	0.40%
Tax expense and effective tax rate	(15.70%)	7.10%