Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			$ 509,457	$ 563,352
Other comprehensive (loss) income	$ (50)	$ (241)	799	(660)
Ending Balance	469,799	539,330	469,799	539,330
Unrealized Gains and (Losses) on Securities Available-for-Sale [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(465)	(107)
Other comprehensive income (loss), before reclassifications			230	(389)
Amounts reclassified from accumulated other comprehensive income			0	0
Other comprehensive (loss) income			230	(389)
Ending Balance	(235)	(496)	(235)	(496)
Other comprehensive income (loss), before reclassifications, tax			(140)	26
Foreign Currency Translation Adjustments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(569)	(135)
Other comprehensive income (loss), before reclassifications			569	(271)
Amounts reclassified from accumulated other comprehensive income			0	0
Other comprehensive (loss) income			569	(271)
Ending Balance	$ 0	$ (406)	0	(406)
Other comprehensive income (loss), before reclassifications, tax			$ (348)	$ 167