Commitments and Contingencies (Schedule of Guarantor Obligations) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Guarantor Obligations [Line Items]
Guarantor Obligations, Short-Term	$ 145,800
Guarantor Obligations, Current Carrying Value	284,309	$ 287,461	$ 235,874
Standby Letters of Credit
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	255,418	242,390	201,212
Loans Sold with Recourse
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 28,891	$ 45,071	$ 34,662