Fair Values - Losses Resulting from Nonrecurring Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total	$ 745	$ 5,731	$ 4,430
Collateral dependent impaired loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total	745	5,296	3,873
Other real estate owned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total	$ 0	$ 435	$ 557