Divesture of Xpress Internacional (Details) - Xpress Internacional $ in Millions		12 Months Ended
	Jan. 17, 2019 USD ($) item	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest, as a percent	95.00%
Cash proceeds	$ 4.5
Note received in disposal	6.0	$ 1.6
Contingent consideration received in disposal	$ 2.5
Number of tractors sold | item	110
Subsequent gain		0.8
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Tractors [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of assets held for sale	$ 2.5	$ 1.7
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for sale			$ 11.6