Equity in Net Assets of Non-consolidated Affiliates - Summarized Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Undistributed earnings of foreign subsidiaries	$ 21	$ 26
SAIC-GMAC [Member]
Schedule of Equity Method Investments [Line Items]
Undistributed earnings of foreign subsidiaries	121
Summarized Balance Sheet Data
Finance receivables, net	9,617
Total assets	9,802
Debt	5,789
Total liabilities	7,973
Summarized Operating Data
Finance charge income	971
Provision for loan losses	45
Interest expense	338
Income before income taxes	463
Net income	$ 347
Ownership percentage	35.00%