Contingencies and Guarantees (Schedule of Guarantor Obligations) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 248,423	$ 267,605	$ 315,732
Standby Letters of Credit
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	236,642	254,703	275,736
Loans Sold with Recourse
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 11,781	$ 12,902	$ 39,996