Commitments and Contingencies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Other Commitments [Line Items]
Liability insurance coverage	$ 100
Self-insurance retention workers' compensation	500
Aggregate deductible for claims between $0 and $3,000 | Expedited Freight
Other Commitments [Line Items]
Company Risk Retention	3,000
Aggregate deductible for claims between $0 and $2,000 | Expedited Freight
Other Commitments [Line Items]
Company Risk Retention	2,000
Aggregate deductible for claims between $3,000 and $5,000 | Expedited Freight
Other Commitments [Line Items]
Company Risk Retention	6,000
Aggregate deductible for claims between $5,000 and $10,000 | Expedited Freight
Other Commitments [Line Items]
Company Risk Retention	2,500
Aggregate deductible for claims between $0 and $250 | Intermodal
Other Commitments [Line Items]
Company Risk Retention	1,000
Minimum | Aggregate deductible for claims between $0 and $3,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	0
Minimum | Aggregate deductible for claims between $0 and $2,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	0
Minimum | Aggregate deductible for claims between $3,000 and $5,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	3,000
Minimum | Aggregate deductible for claims between $5,000 and $10,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	5,000
Minimum | Aggregate deductible for claims between $0 and $250 | Intermodal
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	0
Maximum | Aggregate deductible for claims between $0 and $3,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	3,000
Maximum | Aggregate deductible for claims between $0 and $2,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	2,000
Maximum | Aggregate deductible for claims between $3,000 and $5,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	5,000
Maximum | Aggregate deductible for claims between $5,000 and $10,000
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	10,000
Maximum | Aggregate deductible for claims between $5,000 and $10,000 | Expedited Freight
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	10,000
Maximum | Aggregate deductible for claims between $0 and $250 | Intermodal
Other Commitments [Line Items]
Self-insurance retention liability additional deductible applicable range	$ 1,000