Note 1 - Significant Accounting Policies (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended						9 Months Ended
		Jul. 08, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2021	Oct. 31, 2020	Dec. 31, 2019
Depreciation, Depletion and Amortization, Nonproduction, Total			$ 13,428			$ 20,817			$ 51,274	$ 61,230
Net Income (Loss) Attributable to Parent, Total			$ 7,501	$ (22,343)	$ (2,213)	$ (3,189)	$ 6,071	$ 4,433	$ (17,055)	$ 7,315
Earnings Per Share, Diluted, Total (in dollars per share)	[1]		$ 0.43			$ (0.17)			$ (0.98)	$ 0.39
Insurance Policy Primary Occurence Limit											$ 9,000
Insurance Policy Excess Coverage											$ 1,000
Insurance Policy, Reinstatement Charges									$ 1,000
Proceeds from Divestiture of Businesses									108,375	$ 0
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Total									$ 3,720	$ (0)
Tractors [Member]
Property, Plant and Equipment, Useful Life (Year)									5 years
Property, Plant and Equipment, Salvage Value, Percentage			15.00%						15.00%
Refrigerated Trailers [Member]
Property, Plant and Equipment, Useful Life (Year)									7 years
Dry Van Trailers [Member]
Property, Plant and Equipment, Useful Life (Year)									10 years
Property, Plant and Equipment, Salvage Value, Percentage			25.00%						25.00%
Transport Financial Services [Member] | Discontinued Operations, Held-for-sale [Member]
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net		$ 103,300	$ 0						$ 0				$ 86,620
Disposal Group, Including Discontinued Operation, Consideration		122,300	$ 108,400						108,400
Proceeds from Divestiture of Businesses		108,400
Disposal Group, Including Discontinued Operation, Stock Value		13,900
Disposal Group, Including Discontinued Operation, Earnout Opportuntiy, Maximum		9,900
Disposal Group Including Discontinued Operation, Dispute over Nature of Assets		66,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Total		3,700
Disposal Group Including Discontinued Operation, Assets Advances Against Future Payments For Services Not Yet Performed		62,000
Disposal Group Including Discontinued Operation, Indemnity, Loss Amount		$ 30,000
Disposal Group Including Discontinued Operation, Indemnity, Percentage of Next 30 Million Loss		50.00%
Disposal Group Including Discontinued Operation, Total Indemnification		$ 45,000
Transport Financial Services [Member] | Discontinued Operations, Held-for-sale [Member] | Subsequent Event [Member]
Disposal Group, Including Discontinued Operation, Consideration Returned upon Settlement												$ 28,100
Intangible Assets, Amortization Period [Member]
Depreciation, Depletion and Amortization, Nonproduction, Total									3,200
Net Income (Loss) Attributable to Parent, Total									$ (2,200)
Earnings Per Share, Diluted, Total (in dollars per share)									$ (0.13)

[1] Sum of the individual amounts may not add due to rounding.