Loss Sharing Agreements and FDIC Loss Share Receivable - Schedule of FDIC Loss Share Receivables (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 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			(1,240)	(1,342)
Amortization	$ (3,935)	$ (5,600)	(12,484)	(19,011)
Submission of reimbursable losses to the FDIC			(1,760)	(4,084)
Changes in cash flow assumptions on OREO and other adjustments			12	(1,747)
Balance at end of period	$ 24,406	$ 43,443	$ 24,406	$ 43,443