Other Real Estate Owned (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
OREO activity
Balance, beginning of period	$ 129,340,000	$ 178,183,000
Additions	64,554,000	121,027,000
Sales	(87,358,000)	(123,827,000)
Valuation adjustments	(27,233,000)	(46,043,000)
Balance, end of period	79,303,000	129,340,000
OREO Valuation Allowances	33,600,000	37,400,000
Non-Covered OREO
OREO activity
Balance, beginning of period	30,790,000	57,317,000
Additions	14,177,000	18,486,000
Sales	(17,147,000)	(40,413,000)
Valuation adjustments	(6,793,000)	(4,600,000)
Balance, end of period	21,027,000	30,790,000
Covered OREO
OREO activity
Balance, beginning of period	98,550,000	120,866,000
Additions	50,377,000	102,541,000
Sales	(70,211,000)	(83,414,000)
Valuation adjustments	(20,440,000)	(41,443,000)
Balance, end of period	$ 58,276,000	$ 98,550,000
FDIC reimbursement (as a percent)	80.00%