Commitments and Contingencies Outstanding Commitments to Extend Credit and Letters of Credit (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
ResidentialMortgageRepresentationandWarrantyReserve	$ 2,500,000	$ 2,400,000
ResidentialMortgagePrincipalBalanceFHLBCreditEnhancement	196,000,000
ResidentialMortgageRepurchaseReservesFHLBCreditEnhancement	2,900,000	3,600,000
Commitments to Extend Credit [Member] | Reserve for Off-balance Sheet Activities [Member]
Valuation allowances and Reserves, Balance	4,304,848,000	4,011,741,000
Standby Letters of Credit [Member] | Reserve for Off-balance Sheet Activities [Member]
Valuation allowances and Reserves, Balance	403,981,000	425,095,000
Commercial Letters of Credit [Member] | Reserve for Off-balance Sheet Activities [Member]
Valuation allowances and Reserves, Balance	34,637,000	26,191,000
Residential Mortgage [Member] | Reserve for Off-balance Sheet Activities [Member]
Valuation allowances and Reserves, Balance	$ 5,400,000	$ 6,000,000