Finance Receivables (Investment Of Wholesale Finance Receivables By Internal And External Credit Quality Indicator) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 6,560,245	$ 6,110,256	$ 5,889,519	$ 5,912,130	$ 6,191,158
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	5,607,924	5,265,044	5,073,115	5,087,490	5,377,161
Consumer Portfolio Segment [Member] | Prime [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	4,435,352	4,141,559
Consumer Portfolio Segment [Member] | Sub Prime [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,172,572	1,123,485
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	952,321	845,212	816,404	824,640	813,997
Commercial Portfolio Segment [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	954	0
Commercial Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	7,025	8,383
Commercial Portfolio Segment [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	0	2,076
Commercial Portfolio Segment [Member] | Risk Level, Medium [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	11,557	5,205
Commercial Portfolio Segment [Member] | Risk Level, Low [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 932,785	$ 829,548