Description of Business and Summary of Significant Accounting Policies - Schedule of Disaggregation of Trucking Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 68,860	$ 52,389	$ 214,199	$ 160,066
Trucking [Member]
Disaggregation of Revenue [Line Items]
Total revenue	68,769	52,133	179,160	159,258
Trucking [Member] | USPS [Member]
Disaggregation of Revenue [Line Items]
Total revenue	59,546	45,607	155,849	139,148
Trucking [Member] | Freight Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	6,976	6,224	20,098	18,784
Trucking [Member] | Other Revenue [Member]
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,247	$ 302	$ 3,213	$ 1,326