Goodwill (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 1,491	$ 1,502
Goodwill, Foreign Currency Translation Gain (Loss)	(11)
Transportation Services
Goodwill [Line Items]
Goodwill	61	60
Goodwill, Foreign Currency Translation Gain (Loss)	1
Commercial Industries
Goodwill [Line Items]
Goodwill	814	821
Goodwill, Foreign Currency Translation Gain (Loss)	(7)
Government services
Goodwill [Line Items]
Goodwill	616	$ 621
Goodwill, Foreign Currency Translation Gain (Loss)	$ (5)