Note 3 - Discontinued Operations - Results of Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jul. 08, 2020	Dec. 31, 2019
Current assets of discontinued operations	$ 21,094		$ 21,094			$ 86,620
Current liabilities of discontinued operations	20,226		20,226			6,245
Revenue	210,830	$ 220,459	613,333	$ 654,832
Income (loss) from continuing operations	$ 4,713	$ (4,042)	$ (21,540)	$ 4,961
Income (loss) per basic share from continuing operations (in dollars per share)	$ 0.28	$ (0.22)	$ (1.24)	$ 0.27
Income (loss) per diluted share from continuing operations (in dollars per share)	$ 0.27	$ (0.22)	$ (1.24)	$ 0.27
Transport Financial Services [Member] | Discontinued Operations, Held-for-sale [Member]
Total revenue	$ 142	$ 2,455	$ 5,397	$ 6,561
Operating expenses	(3,601)	515	(2,571)	1,327
Operating income	3,743	1,940	7,968	5,234
Interest expense	0	794	1,948	2,073
Income before income taxes	3,743	1,146	6,020	3,161
Income tax expense	955	293	1,535	807
Net income from discontinued operations, net of tax	2,788	853	4,485	2,354
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	0		0		$ 103,300	86,620
Other short-term assets	21,094		21,094			0
Current assets of discontinued operations	21,094		21,094			86,620
Accounts payable	20,226		20,226			6,245
Current liabilities of discontinued operations	20,226		20,226			$ 6,245
Transport Financial Services [Member] | Discontinued Operations, Held-for-sale [Member] | Pro Forma [Member]
Revenue	210,830	220,459	613,333	654,832
Income (loss) from continuing operations	$ 4,713	$ (4,042)	$ (21,540)	$ 4,961
Income (loss) per basic share from continuing operations (in dollars per share)	$ 0.28	$ (0.22)	$ (1.24)	$ 0.27
Income (loss) per diluted share from continuing operations (in dollars per share)	$ 0.27	$ (0.22)	$ (1.24)	$ 0.27