| Summarized Held for Sale and Discontinued Operations Financial Information | 
 A summary of the carrying amounts of major classes of assets and liabilities, which are included in assets and liabilities held for sale in the Consolidated Balance Sheets, is as follows: 
  
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|   | 
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December 31, 2020 | 
 
| Assets | 
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| Current assets: | 
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  | 
 
Accounts receivable, less allowance of $86 in 2020  | 
 | 
$ | 
19,740  | 
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| Other current assets | 
 | 
1,262  | 
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| Total current assets held for sale | 
 | 
$ | 
21,002  | 
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| Property and equipment | 
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$ | 
48,905  | 
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| Less accumulated depreciation and amortization | 
 | 
28,890  | 
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| Net property and equipment | 
 | 
20,015  | 
 | 
 
| Operating lease right-of-use assets | 
 | 
46,865  | 
 | 
 
Other acquired intangibles, net of accumulated amortization of $12,679 in 2020  | 
 | 
2,621  | 
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| Deferred income taxes | 
 | 
3,253  | 
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| Other assets | 
 | 
3,321  | 
 | 
 
| Valuation allowance on assets held for sale | 
 | 
(22,978) | 
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| Total noncurrent assets held for sale | 
 | 
$ | 
53,097  | 
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| Liabilities  | 
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  | 
 
| Current liabilities: | 
 | 
  | 
 
| Accounts payable | 
 | 
$ | 
4,002  | 
 | 
 
| Accrued expenses | 
 | 
5,070  | 
 | 
 
| Other current liabilities | 
 | 
27  | 
 | 
 
| Current portion of operating lease liabilities | 
 | 
16,825  | 
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| Total current liabilities held for sale | 
 | 
$ | 
25,924  | 
 | 
 
 | 
 | 
 | 
 
|   Operating lease liabilities, less current portion | 
 | 
$ | 
30,024  | 
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|   Other long-term liabilities | 
 | 
4,551  | 
 | 
 
| Total noncurrent liabilities held for sale | 
 | 
$ | 
34,575  | 
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A summary of the results of operations classified as a discontinued operation, net of tax, in the Consolidated Statements of Comprehensive Income for the years ended December 31, 2021, 2020 and 2019 is as follows: 
  
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|   | 
Year Ended | 
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|   | 
December 31, 2021 | 
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December 31, 2020 | 
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December 31, 2019 | 
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| Operating revenue | 
$ | 
17,776  | 
 | 
 | 
 | 
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$ | 
141,433  | 
 | 
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$ | 
195,208  | 
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| Operating expenses: | 
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  | 
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| Purchased transportation | 
3,381  | 
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 | 
 | 
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33,979  | 
 | 
 | 
52,867  | 
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 | 
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| Salaries, wages and employee benefits | 
9,458  | 
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 | 
 | 
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65,695  | 
 | 
 | 
77,162  | 
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 | 
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| Operating leases | 
2,289  | 
 | 
 | 
 | 
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21,982  | 
 | 
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18,918  | 
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 | 
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| Depreciation and amortization | 
—  | 
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 | 
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1,657  | 
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5,715  | 
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| Insurance and claims | 
929  | 
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6,205  | 
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6,707  | 
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| Fuel expense | 
508  | 
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4,279  | 
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6,462  | 
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| Other operating expenses | 
1,627  | 
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 | 
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17,587  | 
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20,969  | 
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| Impairment charge | 
6,967  | 
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 | 
 | 
 | 
28,384  | 
 | 
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—  | 
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| Total operating expenses | 
25,159  | 
 | 
 | 
 | 
 | 
179,768  | 
 | 
 | 
188,800  | 
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| (Loss) income from discontinued operation | 
(7,383) | 
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 | 
 | 
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(38,335) | 
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 | 
6,408  | 
 | 
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| Loss on sale of business | 
(2,860) | 
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 | 
 | 
 | 
—  | 
 | 
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—  | 
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| (Loss) income from discontinued operation before income taxes | 
(10,243) | 
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 | 
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(38,335) | 
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 | 
6,408  | 
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| Income tax (benefit) expense | 
(11) | 
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 | 
 | 
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(9,301) | 
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1,631  | 
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| (Loss) income from discontinued operation, net of tax | 
$ | 
(10,232) | 
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$ | 
(29,034) | 
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$ | 
4,777  | 
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