Commitments and Contingencies (Schedule of Commitments to Extend Credit) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 6,144,177	$ 6,136,313	$ 5,666,483
Commercial Loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	3,746,824	3,748,690	3,386,052
Total consumer
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 2,397,353	$ 2,387,623	$ 2,280,431