Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss) and Associated Income Tax Effects (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity [Abstract]
Unrealized gain (loss) before reclassifications, tax (expense) benefit	$ 3,682	$ (2,282)	$ 337
Unrealized gain (loss) before reclassifications, tax (expense) benefit	18	(28)	15
Reclassification adjustments for items included in Net Income, tax (expense) benefit	(2,608)	(1,472)	3,623
Reclassification adjustments for items included in Net Income, tax (expense) benefit	$ 18	$ (1)	$ 205