Revenue Recognition - Disaggregation of Revenue by Geographical Area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 5,036	$ 3,502	$ 9,810	$ 7,366
United States
Disaggregation of Revenue [Line Items]
Revenue	2,817	2,004	5,510	4,233
North America (excluding United States)
Disaggregation of Revenue [Line Items]
Revenue	113	81	217	166
France
Disaggregation of Revenue [Line Items]
Revenue	540	394	1,059	852
United Kingdom
Disaggregation of Revenue [Line Items]
Revenue	821	452	1,567	947
Europe (excluding France and United Kingdom)
Disaggregation of Revenue [Line Items]
Revenue	696	525	1,369	1,096
Other
Disaggregation of Revenue [Line Items]
Revenue	49	46	88	72
Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(31)	(29)	(64)	(61)
Eliminations | United States
Disaggregation of Revenue [Line Items]
Revenue	(10)	(10)	(19)	(19)
Eliminations | North America (excluding United States)
Disaggregation of Revenue [Line Items]
Revenue	0	0	0	0
Eliminations | France
Disaggregation of Revenue [Line Items]
Revenue	(2)	(3)	(5)	(6)
Eliminations | United Kingdom
Disaggregation of Revenue [Line Items]
Revenue	(16)	(11)	(31)	(27)
Eliminations | Europe (excluding France and United Kingdom)
Disaggregation of Revenue [Line Items]
Revenue	(1)	(4)	(6)	(7)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Revenue	(2)	(1)	(3)	(2)
Transportation | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	3,186	2,127	6,175	4,586
Transportation | Operating Segments | United States
Disaggregation of Revenue [Line Items]
Revenue	2,276	1,505	4,394	3,207
Transportation | Operating Segments | North America (excluding United States)
Disaggregation of Revenue [Line Items]
Revenue	95	71	185	142
Transportation | Operating Segments | France
Disaggregation of Revenue [Line Items]
Revenue	352	255	694	566
Transportation | Operating Segments | United Kingdom
Disaggregation of Revenue [Line Items]
Revenue	222	125	431	307
Transportation | Operating Segments | Europe (excluding France and United Kingdom)
Disaggregation of Revenue [Line Items]
Revenue	215	146	428	334
Transportation | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Revenue	26	25	43	30
Transportation | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(80)	(38)	(139)	(82)
Logistics | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,881	1,404	3,699	2,841
Logistics | Operating Segments | United States
Disaggregation of Revenue [Line Items]
Revenue	551	509	1,135	1,045
Logistics | Operating Segments | North America (excluding United States)
Disaggregation of Revenue [Line Items]
Revenue	18	10	32	24
Logistics | Operating Segments | France
Disaggregation of Revenue [Line Items]
Revenue	190	142	370	292
Logistics | Operating Segments | United Kingdom
Disaggregation of Revenue [Line Items]
Revenue	615	338	1,167	667
Logistics | Operating Segments | Europe (excluding France and United Kingdom)
Disaggregation of Revenue [Line Items]
Revenue	482	383	947	769
Logistics | Operating Segments | Other
Disaggregation of Revenue [Line Items]
Revenue	$ 25	$ 22	$ 48	$ 44