Loans And Allowance For Loan Losses (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Jun. 04, 2011
Mortgage Loans on Real Estate [Line Items]
Total Loans	$ 11,102,269,000	$ 11,102,269,000		$ 4,957,164,000
Covered loans	34,100,000	34,100,000		45,300,000	536,833,000
Recorded losses	83,622,000	83,622,000		107,739,000
Acquisition of covered loans		95.00%
Provision for loan losses, net		1,700,000
Unpaid principal balance for purchased loans	83,622,000	83,622,000		107,739,000
Fair value of collateral less cost, in days		120
Total restructured loans	14,000,000	14,000,000		12,600,000
Investments in impaired loans	17,499,000	17,499,000		11,952,000
Interest that would have been recognized on nonaccrual loans	1,500,000	3,800,000
Interest recovered on nonaccrual loans	200,000	900,000
Percent of accruing loans		0.01%		0.03%
Payments of principal and interest		90
Loans held for sale	64,545,000	64,545,000		21,866,000
Gain on the sale of loans total		50,000	1,000,000
Purchased Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Covered loans	721,831,000	721,831,000	833,951,000
Purchased Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Covered loans				809,200,000
Unpaid principal balance for purchased loans	1,700,000	1,700,000		1,200,000
Restructured Commercial Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Total restructured loans	4,400,000	4,400,000
Mortgage Loans For Sale [Member]
Mortgage Loans on Real Estate [Line Items]
Loans held for sale	42,100,000	42,100,000
Commercial Loans Held For Sale [Member]
Mortgage Loans on Real Estate [Line Items]
Loans held for sale	22,400,000	22,400,000
Regulatory Assistance Covered [Member]
Mortgage Loans on Real Estate [Line Items]
Recorded losses	$ 33,400,000	$ 33,400,000