Contingencies and Guarantees (Schedule of Commitments to Extend Credit) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 6,068,239	$ 6,385,147	$ 6,034,870
Commercial Loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	3,609,266	3,992,089	3,691,193
Total consumer
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$ 2,458,973	$ 2,393,058	$ 2,343,677