Other Real Estate Owned (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
OREO activity
Balance, beginning of period	$ 17,268	$ 22,213	$ 23,496	$ 38,092
Additions	285	7,233	4,200	11,364
Sales	(2,963)	(4,449)	(11,367)	(23,357)
Valuation adjustments	(696)	(395)	(2,435)	(1,497)
Balance, end of period	13,894	24,602	13,894	24,602
OREO Valuation Allowances	2,400		2,400		$ 7,400
Non-Covered OREO
OREO activity
Balance, beginning of period	5,957	4,269	10,736	12,611
Additions		5,957		6,068
Sales		(83)	(4,779)	(8,523)
Valuation adjustments	(373)	(28)	(373)	(41)
Balance, end of period	5,584	10,115	5,584	10,115
Residential mortgage loans in process of foreclosure			7,300
Covered OREO
OREO activity
Balance, beginning of period	11,311	17,944	12,760	25,481
Additions	285	1,276	4,200	5,296
Sales	(2,963)	(4,366)	(6,588)	(14,834)
Valuation adjustments	(323)	(367)	(2,062)	(1,456)
Balance, end of period	$ 8,310	$ 14,487	$ 8,310	$ 14,487
FDIC reimbursement (as a percent)			80.00%
Payable to FDIC (as a percent)			80.00%