Accumulated Other Comprehensive Income (Loss) (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Other income (expense)	$ 157		$ 54
Interest expense excluding Financial Products	(129)		(110)
Interest expense of Financial Products	(150)		(160)
Tax (provision) benefit	(443)		(418)
Reclassifications net of tax	1,111	[1]	922	[1]
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassifications net of tax	(122)		(65)
Reclassification out of Accumulated Other Comprehensive Income | Pension and other postretirement benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Amortization of actuarial gain (loss)	(165)		(130)
Amortization of prior service credit (cost)	13		9
Reclassifications before tax	(152)		(121)
Tax (provision) benefit	52		41
Reclassifications net of tax	(100)		(80)
Reclassification out of Accumulated Other Comprehensive Income | Derivative financial instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassifications before tax	(38)		8
Tax (provision) benefit	14		(3)
Reclassifications net of tax	(24)		5
Reclassification out of Accumulated Other Comprehensive Income | Derivative financial instruments | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Other income (expense)	(35)		10
Reclassification out of Accumulated Other Comprehensive Income | Derivative financial instruments | Interest rate contracts | Machinery, Energy & Transportation
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Other income (expense)	0		(1)
Interest expense excluding Financial Products	(2)		0
Reclassification out of Accumulated Other Comprehensive Income | Derivative financial instruments | Interest rate contracts | Financial Products
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Interest expense of Financial Products	(1)		(1)
Reclassification out of Accumulated Other Comprehensive Income | Available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Other income (expense)	3		14
Tax (provision) benefit	(1)		(4)
Reclassifications net of tax	$ 2		$ 10

[1] 1 Profit attributable to common stockholders.