Loans - Schedule of Activity in Loss Share Receivable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Beginning balance	$ 60,272	$ 113,834
Amortization	(5,747)	(12,102)	$ (2,239)
Charge-offs, write-downs and other (recoveries) losses	(8,072)	(2,245)
External expenses qualifying under loss share agreement	2,677	4,532
Changes due to changes in cash flow projections	(2,800)	(19,084)
FDIC resolution of denied claims	(2,411)	(10,268)
Net payments from FDIC	(14,051)	(14,395)
Ending balance	$ 29,868	$ 60,272	$ 113,834