Other Real Estate Owned - Summary of Activity in Other Real Estate Owned (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Real Estate Owned, Disclosure of Detailed Components [Abstract]
Beginning balance	$ 33,160	$ 33,351	$ 33,351
Loans transferred to other real estate owned	8,636	6,400	11,972
Net gains (losses) on sale and write-downs	(9,449)	(1,523)	(4,585)
Sales proceeds	(9,780)	(2,855)	(7,578)
Ending balance	$ 22,567	$ 35,373	$ 33,160