Description of Business and Summary of Significant Accounting Policies - Schedule of Disaggregates Trucking Revenue from Contracts with Customers (ASC 606-10-50) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 56,493	$ 51,951	$ 145,339	$ 107,677
Trucking [Member]
Disaggregation of Revenue [Line Items]
Total revenue	56,439	51,719	110,391	107,125
Trucking [Member] | USPS Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	49,153	45,358	96,304	93,541
Trucking [Member] | Freight Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	6,561	5,985	13,122	12,560
Trucking [Member] | Other Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	$ 725	$ 376	$ 965	$ 1,024