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Intangible assets and goodwill (Details 2) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 01, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 31, 2015
Carrying amount of goodwill by reportable segment
Goodwill acquired			$ 37	$ 133
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year	$ 7,217		7,217	7,296
Impairments, beginning of year	(602)		(602)	(602)
Goodwill acquired			37	133
Impairment Loss		$ (595)	(595)	0	$ 0
Other Adjustments			(37)	(212)
Goodwill, end of year		7,217	7,217	7,217	7,296
Impairments, end of year		(1,197)	(1,197)	(602)	(602)
Net Goodwill, end of year		6,020	6,020	6,615	6,694
Rail Product Solutions Inc.
Carrying amount of goodwill by reportable segment
Goodwill acquired				53
Changes in carrying amount of goodwill by reportable segment:
Goodwill acquired				53
Net Goodwill, end of year						$ 53
RDS Manufacturing Inc.
Carrying amount of goodwill by reportable segment
Goodwill acquired				59
Changes in carrying amount of goodwill by reportable segment:
Goodwill acquired				59
Net Goodwill, end of year				59
Construction Industries
Carrying amount of goodwill by reportable segment
Goodwill acquired			0	0
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year	285		285	297
Impairments, beginning of year	(22)		(22)	(22)
Goodwill acquired			0	0
Impairment Loss			0	0
Other Adjustments			11	(12)
Goodwill, end of year		296	296	285	297
Impairments, end of year		(22)	(22)	(22)	(22)
Net Goodwill, end of year		274	274	263	275
Resource Industries
Carrying amount of goodwill by reportable segment
Goodwill acquired			0	0
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year	4,145		4,145	4,287
Impairments, beginning of year	(580)		(580)	(580)
Goodwill acquired			0	0
Impairment Loss			(595)	0
Other Adjustments			(35)	(142)
Goodwill, end of year		4,110	4,110	4,145	4,287
Impairments, end of year		(1,175)	(1,175)	(580)	(580)
Net Goodwill, end of year		2,935	2,935	3,565	3,707
Energy & Transportation
Carrying amount of goodwill by reportable segment
Goodwill acquired			37	133
Goodwill reassigned	118
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year	2,738		2,738	2,660
Goodwill acquired			37	133
Impairment Loss			0	0
Other Adjustments			(19)	(55)
Goodwill, end of year		2,756	2,756	2,738	2,660
Net Goodwill, end of year		2,756	2,756	2,738
All Other
Carrying amount of goodwill by reportable segment
Goodwill acquired			0	0
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year	$ 49		49	52
Goodwill acquired			0	0
Impairment Loss			0	0
Other Adjustments			6	(3)
Goodwill, end of year		$ 55	$ 55	$ 49	$ 52