Other Real Estate Owned (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
OREO activity
Balance, beginning of period	$ 107,530,000	$ 178,164,000	$ 129,340,000	$ 178,183,000
Additions	33,436,000	37,516,000	41,728,000	71,654,000
Sales	(15,872,000)	(35,919,000)	(37,110,000)	(60,300,000)
Valuation adjustments	(7,593,000)	(17,220,000)	(16,457,000)	(26,996,000)
Balance, end of period	117,501,000	162,541,000	117,501,000	162,541,000
OREO Valuation Allowances	38,800,000		38,800,000		37,400,000
Non-Covered OREO
OREO activity
Balance, beginning of period	29,074,000	56,342,000	30,790,000	57,317,000
Additions	10,476,000	3,967,000	12,693,000	10,528,000
Sales	(1,540,000)	(11,083,000)	(4,417,000)	(17,147,000)
Valuation adjustments	(3,343,000)	(1,592,000)	(4,399,000)	(3,064,000)
Balance, end of period	34,667,000	47,634,000	34,667,000	47,634,000
Covered OREO
OREO activity
Balance, beginning of period	78,456,000	121,822,000	98,550,000	120,866,000
Additions	22,960,000	33,549,000	29,035,000	61,126,000
Sales	(14,332,000)	(24,836,000)	(32,693,000)	(43,153,000)
Valuation adjustments	(4,250,000)	(15,628,000)	(12,058,000)	(23,932,000)
Balance, end of period	$ 82,834,000	$ 114,907,000	$ 82,834,000	$ 114,907,000
FDIC reimbursement (as a percent)			80.00%