Note 15 - Asset Dispositions, Assets Held for Sale and Asset Impairments - Activity in Assets Held for Sale (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)
Beginning balance			18
Additions			1
Sales				(8)
Transfers	0	(1)	(1)	(1)
Transfers	$ 0	$ (3,000)	$ (1,500)	$ (3,000)
Ending balance	9		9
Vessels Held for Sale [Member]
Beginning balance	12	20	18	23
Beginning balance	$ 8,591	$ 31,214	$ 14,421	$ 34,396
Additions	1	0	1	0
Additions	$ 2,500	$ 0	$ 2,500	$ 0
Sales	(4)	(5)	(9)	(8)
Sales	$ (4,229)	$ (11,000)	$ (8,559)	$ (14,182)
Ending balance	9	14	9	14
Ending balance	$ 6,862	$ 17,214	$ 6,862	$ 17,214