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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Intangible assets and goodwill (Details 2) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 01, 2015	Oct. 31, 2015
Carrying amount of goodwill by reportable segment
Goodwill acquired		$ 0	$ 37
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year		7,217	7,217
Impairments, beginning of year		(1,197)	(602)
Goodwill acquired		0	37
Impairment Loss	$ (595)	0	(595)	$ 0
Other Adjustments		180	(37)
Goodwill, end of year	7,397	7,397	7,217	7,217
Impairments, end of year	(1,197)	(1,197)	(1,197)	(602)
Net Goodwill, end of year	6,200	6,200	6,020	6,615
Rail Product Solutions Inc.
Changes in carrying amount of goodwill by reportable segment:
Net Goodwill, end of year						$ 53
RDS Manufacturing Inc.
Changes in carrying amount of goodwill by reportable segment:
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		296	285
Impairments, beginning of year		(22)	(22)
Goodwill acquired		0	0
Impairment Loss		0	0
Other Adjustments		9	11
Goodwill, end of year	305	305	296	285
Impairments, end of year	(22)	(22)	(22)	(22)
Net Goodwill, end of year	283	283	274	263
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		4,110	4,145
Impairments, beginning of year		(1,175)	(580)
Goodwill acquired		0	0
Impairment Loss		0	(595)
Other Adjustments		122	(35)
Goodwill, end of year	4,232	4,232	4,110	4,145
Impairments, end of year	(1,175)	(1,175)	(1,175)	(580)
Net Goodwill, end of year	3,057	3,057	2,935	3,565
Energy & Transportation
Carrying amount of goodwill by reportable segment
Goodwill acquired		0	37
Changes in carrying amount of goodwill by reportable segment:
Goodwill, beginning of year		2,756	2,738
Goodwill acquired		0	37
Impairment Loss		0	0
Other Adjustments		50	(19)
Goodwill, end of year	2,806	2,806	2,756	2,738
Net Goodwill, end of year	2,806	2,806	2,756
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		55	49
Goodwill acquired		0	0
Impairment Loss		0	0
Other Adjustments		(1)	6
Goodwill, end of year	$ 54	$ 54	$ 55	$ 49