Guarantees (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Product Warranty Liability [Line Items]
Balance as of January 1	$ 1,199	$ 1,212
Warranties and performance guarantees issued	142	154
Settlements made	120	131
Other	13	6
Balance as of June 30	$ 1,234	$ 1,241