Loans (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Financing Receivable, Modifications [Line Items]
Partial charge-offs on impaired loans	$ 88,700,000	$ 53,600,000
Recorded investment, related to loans	92,700,000	162,300,000
Recorded investment	200,400,000	250,933,000
Troubled debt restructurings	72,600,000	80,700,000
TDR's considered current	47,900,000	50,300,000
Commitments to lend additional funds to borrowers	502,000	434,000
With No Related Allowance Recorded [Member]
Financing Receivable, Modifications [Line Items]
Partial charge-offs on impaired loans	37,600,000	12,000,000
With An Allowance Recorded [Member]
Financing Receivable, Modifications [Line Items]
Partial charge-offs on impaired loans	51,100,000	41,600,000
Allowance For Loans And Leases Receivable [Member]
Financing Receivable, Modifications [Line Items]
Allowance for loans individually evaluated for impairment	$ 42,800,000	$ 66,900,000