Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue from operations	$ 1,603,690	$ 1,400,046	$ 4,768,418	$ 3,845,970
LTL Service Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from operations	1,582,952	1,378,339	4,703,392	3,787,721
Other Service Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from operations	$ 20,738	$ 21,707	$ 65,026	$ 58,249