Other Real Estate Owned (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Real Estate Owned Rollforward [Line Items]
Other Real Estate Owned Beginning Balance	$ 295,225	$ 342,145	$ 303,508	$ 405,902
Other Real Estate Owned Write Downs	(12,619)	(15,211)	(26,857)	(37,833)
Other Real Estate Owned Additions	36,609	46,116	121,911	191,783
Other Real Estate Owned Sales	(32,290)	(77,448)	(106,257)	(265,998)
Othe Real Estate Owned Other Adjustments	(287)	(132)	(5,667)	1,616
Other Real Estate Owned Ending Balance	286,638	295,470	286,638	295,470
Non Covered Under Loss Sharing Agreements With F D I C [Member] | Mortgages [Member]
Other Real Estate Owned Rollforward [Line Items]
Other Real Estate Owned Beginning Balance	89,633	93,795	86,852	130,982
Other Real Estate Owned Write Downs	(1,844)	(661)	(2,952)	(8,939)
Other Real Estate Owned Additions	15,787	14,184	46,070	69,369
Other Real Estate Owned Sales	(13,008)	(22,111)	(37,274)	(107,282)
Othe Real Estate Owned Other Adjustments	(89)	(132)	(2,217)	945
Other Real Estate Owned Ending Balance	90,479	85,075	90,479	85,075
Non Covered Under Loss Sharing Agreements With F D I C [Member] | Commercial Or Construction [Member]
Other Real Estate Owned Rollforward [Line Items]
Other Real Estate Owned Beginning Balance	49,787	65,125	48,649	135,862
Other Real Estate Owned Write Downs	(2,714)	(2,881)	(3,499)	(8,767)
Other Real Estate Owned Additions	2,853	4,340	13,824	26,598
Other Real Estate Owned Sales	(5,148)	(16,157)	(15,482)	(103,556)
Othe Real Estate Owned Other Adjustments	(1)	0	1,285	290
Other Real Estate Owned Ending Balance	44,777	50,427	44,777	50,427
Covered Under Loss Sharing Agreements With F D I C [Member] | Mortgages [Member]
Other Real Estate Owned Rollforward [Line Items]
Other Real Estate Owned Beginning Balance	47,900	44,340	47,792	39,660
Other Real Estate Owned Write Downs	(2,222)	(1,381)	(3,369)	(3,166)
Other Real Estate Owned Additions	7,276	6,247	15,870	22,796
Other Real Estate Owned Sales	(7,057)	(3,278)	(13,211)	(13,743)
Othe Real Estate Owned Other Adjustments	615	(240)	(570)	141
Other Real Estate Owned Ending Balance	46,512	45,688	46,512	45,688
Covered Under Loss Sharing Agreements With F D I C [Member] | Commercial Or Construction [Member]
Other Real Estate Owned Rollforward [Line Items]
Other Real Estate Owned Beginning Balance	107,905	138,885	120,215	99,398
Other Real Estate Owned Write Downs	(5,839)	(10,288)	(17,037)	(16,961)
Other Real Estate Owned Additions	10,693	21,345	46,147	73,020
Other Real Estate Owned Sales	(7,077)	(35,902)	(40,290)	(41,417)
Othe Real Estate Owned Other Adjustments	(812)	240	(4,165)	240
Other Real Estate Owned Ending Balance	$ 104,870	$ 114,280	$ 104,870	$ 114,280