Securities Sold under Agreements to Repurchase - Securities Sold under Agreements to Repurchase (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Disclosure of Repurchase Agreements [Abstract]
Securities sold under agreements to repurchase	$ 75,066	$ 73,310	$ 51,109
Total	$ 75,066	$ 73,310	$ 51,109