Loss Sharing Agreements and FDIC Loss Share Receivable - Schedule of FDIC Loss Share Receivables (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 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	(258)	(1,852)
Amortization	(4,386)	(6,013)
Submission of reimbursable losses to the FDIC	(1,658)	(78)
Changes in cash flow assumptions on OREO and other adjustments	(12)	(712)
Balance at end of period	$ 33,564	$ 60,972