Financing Receivables and Allowance for Losses (Details) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable [Line Items]
Financing receivables, net of deferred income		$ 87,204	$ 87,204	$ 126,561
Allowance for losses		(3,457)	(3,457)	(4,104)	$ (4,231)	$ (4,025)
Financing receivables, net	[1]	83,748	83,748	122,457
Financing receivable held for sale		0	29,016
Assets of Businesses Held for Sale [Member]
Financing Receivable [Line Items]
Financing receivable held for sale		0	5,508
Loans Receivables [Member]
Financing Receivable [Line Items]
Financing receivables, net of deferred income		82,196	82,196	120,007
Financing Receivable [Member]
Financing Receivable [Line Items]
Financing receivables, net of deferred income		$ 5,008	$ 5,008	$ 6,554

[1] Amounts may not add due to rounding.