Loss Sharing Agreements and FDIC Loss Share Receivable - Schedule of FDIC Loss Share Receivables (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period			$ 39,878	$ 69,627
Reversal of loan loss provision recorded on FDIC covered loans			(797)	(843)
Amortization	$ (4,163)	$ (7,398)	(8,549)	(13,411)
Submission of reimbursable losses to the FDIC			(1,287)	(3,243)
Changes in cash flow assumptions on OREO and other adjustments			(21)	(1,678)
Balance at end of period	$ 29,224	$ 50,452	$ 29,224	$ 50,452