Guarantees (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Guarantor Obligations [Line Items]
Service and product warranties and product performance guarantees - beginning of year	$ 1,360	$ 1,332
Warranties and performance guarantees issued	197	232
Settlements made	(256)	(223)
Other	(34)	22
Service and product warranties and product performance guarantees - end of period	1,267	1,363
Performance Guarantee [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 83