Other Real Estate Owned (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
OREO activity
Balance, beginning of year	$ 178,183,000	$ 113,866,000
Additions	121,027,000	184,119,000
Sales	(123,827,000)	(74,082,000)
Valuation adjustments	(46,043,000)	(45,720,000)
Balance, end of year	129,340,000	178,183,000
OREO Valuation Allowances	37,400,000	5,500,000
Non-Covered OREO
OREO activity
Balance, beginning of year	57,317,000	53,308,000
Additions	18,486,000	59,382,000
Sales	(40,413,000)	(34,645,000)
Valuation adjustments	(4,600,000)	(20,728,000)
Balance, end of year	30,790,000	57,317,000
Covered OREO
OREO activity
Balance, beginning of year	120,866,000	60,558,000
Additions	102,541,000	124,737,000
Sales	(83,414,000)	(39,437,000)
Valuation adjustments	(41,443,000)	(24,992,000)
Balance, end of year	$ 98,550,000	$ 120,866,000
FDIC reimbursement (as a percent)	80.00%