Guarantees and Product Warranty (Details 2) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Movement in Standard Product Warranty Accrual
Warranty liability, beginning balance	$ 1,426	$ 1,367
Reduction in liability (payments)	(650)	(1,071)
Increase in liability (new warranties)	604	1,130
Warranty liability, ending balance	$ 1,380	1,426
Product warranty accrual, preexisting, increase (decrease)		$ 170