Income taxes (Details 4) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Pension	$ 1,887	$ 1,694
Postemployment benefits other than pensions	1,318	1,339
Tax carryforwards	1,999	1,098
Warranty reserves	339	359
Stock based compensation	316	356
Inventory	93	129
Allowance for credit losses	209	203
Post sale discounts	207	185
Other employee compensation and benefits	262	269
Other-net	476	427
Deferred income tax assets, Total	7,106	6,059
Deferred income tax liabilities:
Capital and intangible assets	(2,455)	(2,561)
Bond discount	(223)	(225)
Translation	(368)	(343)
Other outside basis differences	(227)	0
Undistributed profits of non-U.S. subsidiaries	(285)	(82)
Deferred income tax liabilities, Total	(3,558)	(3,211)
Valuation allowance for deferred tax assets	(1,102)	(816)
Deferred income taxes-net	$ 2,446	$ 2,032