Commitments and Contingencies (Schedule of Remaining Contractual Loan Commitments by Class) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 5,116,633	$ 4,151,541	$ 3,892,865
Commercial Loan [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	3,020,138	2,431,023	2,227,184
Total consumer
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 2,096,495	$ 1,720,518	$ 1,665,681