Other Assets Acquired through Foreclosure - Changes in Other Assets Acquired through Foreclosure (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Property	Dec. 31, 2013 Property	Dec. 31, 2012
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Gains (losses), net, Net Balance	$ 124	$ 932	$ 493
Number of Real Estate Properties	67	70