Finance Receivables And Loans, Net (Schedule Of Pass And Criticized Credit Quality Indicators Of Finance Receivables) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	$ 110,876	$ 111,600	$ 99,856
Commercial Portfolio Segment [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	37,188	37,535	$ 34,757
Commercial Portfolio Segment [Member] | Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	34,486	35,000
Commercial Portfolio Segment [Member] | Commercial Loan [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	2,702	2,535
Commercial Portfolio Segment [Member] | Commercial And Industrial Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	30,829	31,469
Commercial Portfolio Segment [Member] | Commercial And Industrial Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	29,008	29,613
Commercial Portfolio Segment [Member] | Commercial And Industrial Automobile [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	1,821	1,856
Commercial Portfolio Segment [Member] | Commercial And Industrial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	2,863	2,640
Commercial Portfolio Segment [Member] | Commercial And Industrial Other [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	2,144	2,122
Commercial Portfolio Segment [Member] | Commercial And Industrial Other [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	719	518
Commercial Portfolio Segment [Member] | Commercial Real Estate Automobile [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	3,496	3,426
Commercial Portfolio Segment [Member] | Commercial Real Estate Automobile [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	3,334	3,265
Commercial Portfolio Segment [Member] | Commercial Real Estate Automobile [Member] | Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance receivables and loans, net	$ 162	$ 161