Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax	$ (76)	$ 223	$ 81
Other comprehensive income (loss) before reclassifications, tax	132	(50)
Unrealized Gains and (Losses) on Securities Available-for-Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax	(76)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax	$ 132