Variable Interest Entities - Assets and Liabilities of Other VIE's (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Assets	$ 65,904	$ 47,608
Liabilities	57,852	40,216
Finance receivables, net	36,781	33,000
Secured debt	30,689	25,173
Other VIE [Member]
Variable Interest Entity [Line Items]
Assets	3,652	3,696
Liabilities	2,941	3,184
Finance receivables, net	3,200	3,600
Secured debt	$ 2,600	$ 2,500