Goodwill (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 1,506	$ 1,502
Goodwill, Foreign Currency Translation Gain (Loss)	4
Transportation Services
Goodwill [Line Items]
Goodwill	65	60
Goodwill, Foreign Currency Translation Gain (Loss)	5
Commercial Industries
Goodwill [Line Items]
Goodwill	823	821
Goodwill, Foreign Currency Translation Gain (Loss)	2
Government services
Goodwill [Line Items]
Goodwill	618	$ 621
Goodwill, Foreign Currency Translation Gain (Loss)	$ (3)