Annual report pursuant to Section 13 and 15(d)

Accounting Policies (Details)

v3.19.3.a.u2
Accounting Policies (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
USD ($)
Days
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Jan. 01, 2019
USD ($)
Accounting Policies [Line Items]        
Number of principal reporting segments 3      
Operating lease right-of-use assets $ 151,657 $ 0    
Accounting Policies, Use of Estimates [Abstract]        
Minimum number of days past due for receivable reserve | Days 90      
Average monthly revenue adjustments $ 278      
Average monthly revenue $ 117,533      
Average monthly revenue adjustments as a percentage of monthly revenue 0.20%      
Number of days in revenue adjustment reserve, minimum | Days 35      
Number of days in revenue adjustment reserve, maximum | Days 105      
Self insurance retention liability $ 3,000      
Brokerage liability self-insured retention 100      
Self insurance limit on individual vehicle and general claims 7,500      
Self-insurance retention Workers' compensation 350      
Self Insurance Reserve 66,176 54,228    
Self Insurance Reserve, Noncurrent 49,810      
Insurance Settlements Receivable $ 34,091 28,520    
Accounting Policies, Cash and Cash Equivalents [Abstract]        
Maximum term for liquid investments to be considered cash equivalents, in months 3 months      
Accounting Policies, Property and Equipment [Abstract]        
Depreciation $ 30,896 33,045 $ 30,862  
Accounting Policies, Software Development [Abstract]        
Capitalized software development costs 24,944 21,492    
Capitalized computer software, accumulated amortization 17,190 15,611    
Capitalized Computer Software, Amortization 1,870 1,905 1,816  
Capitalized software future estimated amortization expense        
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic 945 881 700  
Accounting Policies, Share-based Payments [Abstract]        
Operating Lease, Liability $ 152,140      
Software and Software Development Costs [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Property and equipment, useful life 5 years      
Capitalized software future estimated amortization expense        
2020 $ 1,980      
2021 1,649      
2022 1,370      
2023 1,098      
2024 740      
Total $ 6,837      
Stock Option [Member]        
Accounting Policies, Share-based Payments [Abstract]        
Period from grant date of stock options to expiration (in years) 7 years      
Share-based awards, vesting period 3 years      
Minimum [Member]        
Accounting Policies [Line Items]        
Operating lease right-of-use assets       $ 130,000
Accounting Policies, Share-based Payments [Abstract]        
Operating Lease, Liability       130,000
Minimum [Member] | Building [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Property and equipment, useful life 30 years      
Minimum [Member] | Equipment [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Property and equipment, useful life 3 years      
Maximum [Member]        
Accounting Policies [Line Items]        
Operating lease right-of-use assets       150,000
Accounting Policies, Share-based Payments [Abstract]        
Operating Lease, Liability       $ 150,000
Maximum [Member] | Building [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Property and equipment, useful life 40 years      
Maximum [Member] | Equipment [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Property and equipment, useful life 10 years      
Aggregate deductible for claims between $3,000 and $5,000 [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additional deductible $ 6,000      
Aggregate deductible for claims between $3,000 and $5,000 [Member] | Minimum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additonal deductible applicable range 3,000      
Aggregate deductible for claims between $3,000 and $5,000 [Member] | Maximum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additonal deductible applicable range 5,000      
Aggregate deductible for claims between $5,000 and $10,000 [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additional deductible 2,500      
Aggregate deductible for claims between $5,000 and $10,000 [Member] | Minimum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additonal deductible applicable range 5,000      
Aggregate deductible for claims between $5,000 and $10,000 [Member] | Maximum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self insurance retention liability additonal deductible applicable range 10,000      
State of Ohio [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Self-insurance retention Workers' compensation $ 500      
Expedited Freight [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Reserve percentage for past due accounts receivable 50.00%      
Accounting Policies, Property and Equipment [Abstract]        
Depreciation $ 22,993 25,453 23,260  
Intermodal [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Reserve percentage for past due accounts receivable 10.00%      
Self insurance retention liability $ 50      
Accounting Policies, Property and Equipment [Abstract]        
Depreciation $ 3,086 1,719 1,867  
Pool Distribution [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Reserve percentage for past due accounts receivable 25.00%      
Accounting Policies, Property and Equipment [Abstract]        
Depreciation $ 4,884 5,871 5,732  
Truckload [Member] | Aggregate deductible for claims between $0 and $5,000 [Member] | Minimum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Liability insurance coverage 0      
Truckload [Member] | Aggregate deductible for claims between $0 and $5,000 [Member] | Maximum [Member]        
Accounting Policies, Use of Estimates [Abstract]        
Liability insurance coverage 5,000      
Intersegment Eliminations [Member]        
Accounting Policies, Property and Equipment [Abstract]        
Depreciation $ (67) $ 2 $ 3