Loans Receivable and Allowance for Loan Losses - Schedule of FDIC Loss Sharing Receivable (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
FDIC Indemnification Asset [Roll Forward]
Beginning Balance				$ 2,320				$ 10,046	$ 2,320	$ 10,046	$ 12,343
Increase in FDIC loss sharing receivable net of clawback liability									(3,872)	(4,689)	2,819
Increased estimated cash flows from covered OREO									3,138	0	0
Other activity, net									248	2,409	1,610
Cash receipts from FDIC									(3,917)	(5,446)	(6,726)
Ending Balance	$ (2,083)				$ 2,320				(2,083)	2,320	10,046
Provision for loan losses									16,694	10,058	5,055
Effect attributable to FDIC loss share arrangements									3,872	4,689	(2,819)
Provision for loan losses	$ 6,173	$ 2,094	$ 9,335	$ 2,964	$ 2,459	$ 5,035	$ 2,886	$ 4,368	$ 20,566	$ 14,747	$ 2,236