Loans Receivable and Allowance for Loan Losses - Schedule of FDIC Loss Sharing Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ 3,427	$ 8,272	$ 2,320	$ 10,046
Increased (decreased) estimated cash flows	(4,411)	(156)	(3,740)	(1,622)
Other activity, net	334	983	468	1,972
Cash receipts from FDIC	(805)	(180)	(503)	(1,477)
Ending balance	(1,455)	8,919	(1,455)	8,919
Provision for loan losses	4,924	2,730	8,559	5,631
Effect attributable to FDIC loss share arrangements	4,411	156	3,740	1,622
Provision for loan losses	$ 9,335	$ 2,886	$ 12,299	$ 7,253