Loans Receivable and Allowance for Loan Losses - Schedule of FDIC Loss Sharing Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ (1,455)	$ 8,919	$ 2,320	$ 10,046
Decreased estimated cash flows from covered loans	(105)	(1,813)	(3,845)	(3,435)
Increased estimated cash flows from covered OREO	3,138	0	3,138	0
Other activity, net	61	741	529	2,713
Cash receipts from FDIC	(1,437)	(1,852)	(1,940)	(3,329)
Ending balance	202	5,995	202	5,995
Provision for loan losses	1,989	3,222	10,548	8,853
Effect attributable to FDIC loss share arrangements	105	1,813	3,845	3,435
Provision for loan losses	$ 2,094	$ 5,035	$ 14,393	$ 12,288