Securities - Proceeds from Sales of Securities, Gross Realized Gains and Losses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Amortized Cost And Fair Value Debt Securities [Abstract]
Sale proceeds	$ 3,075	$ 7,242	$ 18,088	$ 7,758
Gross realized gains	107	130	112	144
Gross realized losses		89		89
Gains from securities called or settled by the issuer				$ 3