Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits - beginning of the year	$ 1,139	$ 1,065
Gross increases related to prior year tax positions	394	166
Gross increases related to current year tax positions	488	153
Lapse of applicable statute of limitations	(189)	(245)
Gross unrecognized tax benefits - end of year	$ 1,832	$ 1,139