Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - (Disaggregated Revenue) (Details)

v3.20.4
Significant Accounting Policies - (Disaggregated Revenue) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disaggregation of Revenue [Line Items]      
Revenue from operations $ 4,015,129 $ 4,109,111 $ 4,043,695
LTL Service Revenue [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from operations 3,961,054 4,055,467 3,982,658
Other Service Revenue [Member]      
Disaggregation of Revenue [Line Items]      
Revenue from operations $ 54,075 $ 53,644 $ 61,037