Noncovered Other Real Estate Owned (Summary of Noncovered Other Real Estate Owned) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other Real Estate Owned [Line Items]
Balance, beginning of period	$ 45,434
Transfers in, write-downs	2,564	2,087
Proceeds from sale of OREO property	(12,278)	(4,800)	(8,098)
Net realized gain on sale of other real estate owned	9,310	5,253	(183)
Balance, end of period	51,019	45,434
Noncovered Loans [Member]
Other Real Estate Owned [Line Items]
Balance, beginning of period	30,991	19,037
Transfers in, net of write-downs ($315 and $193, respectively)	8,834	19,006
Transfers in, write-downs	315	193
OREO improvements	730	1,635
Additional OREO write-downs	(5,641)	(3,962)
Proceeds from sale of OREO property	(12,278)	(4,800)
Net realized gain on sale of other real estate owned	257	75
Balance, end of period	$ 22,893	$ 30,991