Commitments and Contingencies (Schedule of Guarantor Obligations) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Guarantor Obligations [Line Items]
Guarantor Obligations, Short-Term	$ 132,700
Guarantor Obligations, Current Carrying Value	265,538	$ 287,461	$ 271,095
Standby Letters of Credit
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	243,071	242,390	227,835
Loans Sold with Recourse
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 22,467	$ 45,071	$ 43,260