Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Changes in goodwill
Balance at beginning of period	$ 2,405	$ 2,465
Acquisitions		11
Foreign currency translation adjustments	10	(71)
Dispositions and reclassifications to assets held for sale	71
Other		0
Balance at end of period	2,344	2,405
Operating Segments | Transportation
Changes in goodwill
Balance at beginning of period	815	854
Acquisitions		3
Foreign currency translation adjustments	6	(42)
Dispositions and reclassifications to assets held for sale	15
Other		0
Balance at end of period	806	815
Operating Segments | Facilities
Changes in goodwill
Balance at beginning of period	1,087	1,152
Acquisitions		8
Foreign currency translation adjustments	3	(19)
Dispositions and reclassifications to assets held for sale	56
Other		(54)
Balance at end of period	1,034	1,087
Operating Segments | Supply and Logistics
Changes in goodwill
Balance at beginning of period	503	459
Acquisitions		0
Foreign currency translation adjustments	1	(10)
Other		54
Balance at end of period	$ 504	$ 503