Segment Reporting - Selected Financial Data for Each of Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 5,036	$ 3,502	$ 9,810	$ 7,366
Operating income (loss)	246	(141)	448	(60)
Depreciation and amortization	205	196	397	379
Transaction and integration costs	35	46	53	90
Restructuring income (expense)	(2)	50	2	53
Operating Segments | Transportation
Segment Reporting Information [Line Items]
Revenue	3,186	2,127	6,175	4,586
Operating income (loss)	255	(15)	464	105
Depreciation and amortization	117	113	232	223
Transaction and integration costs	2	13	3	20
Operating Segments | Logistics
Segment Reporting Information [Line Items]
Revenue	1,881	1,404	3,699	2,841
Operating income (loss)	71	(43)	139	(5)
Depreciation and amortization	85	80	159	149
Transaction and integration costs	7	18	12	25
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Operating income (loss)	(80)	(83)	(155)	(160)
Depreciation and amortization	3	3	6	7
Transaction and integration costs	26	15	38	45
Eliminations
Segment Reporting Information [Line Items]
Revenue	(31)	(29)	(64)	(61)
Operating income (loss)	0	0	0	0
Depreciation and amortization	$ 0	$ 0	$ 0	$ 0