Note 12 - Properties and Equipment, Accrued Costs and Expenses, Other Current Liabilities and Other Liabilities (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Number of Vessels	146	146
Number of Vessels, Held for Sale	24	24	46	46	38	46
Depreciation, Total		$ 53,614	$ 57,629
Salvage Value [Member]
Depreciation, Total	$ 3,800
Depreciation, Per Share (in dollars per share) \| $ / shares	$ 0.09

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Name:	us-gaap_Depreciation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration