Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			$ 509,457	$ 563,352
Other comprehensive income (loss)	$ 591	$ (152)	850	(419)
Ending Balance	466,106	558,973	466,106	558,973
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			281	(99)
Amounts reclassified from accumulated other comprehensive income			0	0
Other comprehensive income (loss)			281	(99)
Ending Balance	(184)	(206)	(184)	(206)
Other comprehensive income (loss), before reclassifications, tax			(171)	61
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	(320)
Amounts reclassified from accumulated other comprehensive income			0	0
Other comprehensive income (loss)			569	(320)
Ending Balance	$ 0	$ (455)	0	(455)
Other comprehensive income (loss), before reclassifications, tax			$ (348)	$ 195