Receivables - Receivables and Receivables held for Sale (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		$ 100	$ 163	$ 357	$ 652
Modifications, primarily interest rate modifications		41	54	141	218
Re-age of past due account		59	109	216	434
Total	[1]	100	163	357	652
Amount reclassified as re-ages				160
First lien [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		19	127	161	521
Second lien [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		13	17	41	68
Real Estate Secured Receivables Held for Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		$ 68	$ 19	$ 155	$ 63

[1] During the first quarter of 2015, it was determined that loan balances totaling $160 million previously reported as modifications in the table above during the first quarter of 2014 should have been reported as a re-age. Accordingly, the modification and re-age information presented in the table above for the nine months ended September 30, 2014 has been adjusted to reflect the corrected classification. The total amounts reported remain unchanged.