Securities - Proceeds from Sales of Securities, Gross Realized Gains and Losses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Amortized Cost and Fair Value Debt Securities [Abstract]
Sale proceeds		$ 927	$ 18,088	$ 8,686
Gross realized gains			113	144
Gross realized losses				89
Gains from securities called or settled by the issuer	$ 1	$ 80	$ 1	$ 83