Acquisitions (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 02, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquisitions
Net cash paid for acquisition		$ 47	$ 392	$ 59
ECM S.p.A.
Acquisitions
Percentage of equity acquired (as a percent)	100.00%
Net cash paid for acquisition	$ 225
Payments to acquire businesses, gross	249
Assets acquired
Tangible assets acquired	109
Cash	25
Receivables	28
Inventory	29
Property, plant and equipment	17
Finite-lived intangible assets acquired	112
Business Combination, Goodwill	$ 109
Finite-lived intangible assets, weighed average useful life (in years)	13 years
Liabilities assumed
Business Combination, Accounts Payable	$ 38
Business Combination, Deferred Tax Liabilities	29
Business Combination, debt assumed	1
Total liabilities assumed	79
Downer Freight Rail
Acquisitions
Net cash paid for acquisition	97
Assets acquired
Tangible assets acquired	86
Receivables	23
Inventory	40
Property, plant and equipment	15
Finite-Lived Customer Relationships, Gross	6
Finite-lived intangible assets acquired	6
Business Combination, Goodwill	$ 18
Finite-lived intangible assets, weighed average useful life (in years)	15 years
Liabilities assumed
Total liabilities assumed	$ 14