Commitments and Contingencies (Schedule of Remaining Contractual Loan Commitments by Class) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 4,045,063	$ 3,563,050
Commercial [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	2,468,787	1,911,514
Consumer Loan [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 1,576,276	$ 1,651,536