Allowance for Loan Losses, Analysis of Changes in the Allowance for Loan Losses (Details) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Impaired [Line Items]
Number of months of performance trouble debt restructuring returns to accrual status		6 months
Allowance for loan and lease losses, period decrease		$ (16,400,000)
Allowance for loan and lease losses period decrease percentage		65.80%
Increase decrease in allowance for loan and lease losses write offs		17,400,000
Allowance for credit losses loans sold charged off	19,600,000	28,600,000
Allowance for loan losses [Abstract]
Balance, Beginning of Period		39,958,000	28,419,000	12,333,000
Charge-offs		33,946,000	14,597,000	16,238,000
Recoveries		3,269,000	1,298,000	187,000
Net loans charged-off		30,677,000	13,299,000	16,051,000
Reclass to allowance for contingent liabilities		0	(50,000)	51,000
Provision for loan losses		8,500,000	24,888,000	32,086,000
Balance, End of Period		17,781,000	39,958,000	28,419,000
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses, period decrease		(18,000,000)
Allowance for loan losses [Abstract]
Charge-offs		8,534,000	9,490,000	8,501,000
Recoveries		2,456,000	781,000	69,000
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses, period decrease		4,000,000
Allowance for loan losses [Abstract]
Charge-offs		15,794,000	4,059,000	2,788,000
Real Estate Construction [Member]
Allowance for loan losses [Abstract]
Charge-offs		3,671,000	232,000	3,548,000
Recoveries		340,000	415,000	0
Residential Mortgages (1st and 2nd Liens) [Member]
Allowance for loan losses [Abstract]
Charge-offs		3,727,000	411,000	769,000
Recoveries		115,000	3,000	0
Home Equity [Member]
Allowance for loan losses [Abstract]
Charge-offs		1,953,000	191,000	315,000
Recoveries		246,000	2,000	0
Consumer [Member]
Allowance for loan losses [Abstract]
Charge-offs		267,000	214,000	317,000
Recoveries		112,000	97,000	118,000
Minimum [Member]
Financing Receivable, Impaired [Line Items]
Commercial and industrial loans		$ 250,000