Note 2 - Acquisitions (Details Textual) $ / shares in Units, $ in Thousands			3 Months Ended	12 Months Ended
	Jul. 05, 2023 USD ($)	Apr. 22, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Jul. 03, 2023
Business Combination, Bargain Purchase, Gain Recognized, Amount				$ (0)	$ 1,300	$ (0)
Warrants Issued to Acquire Swire Pacific Offshore Holdings Ltd. [Member]
Class of Warrant or Right, Issued During Period, Exercise Price (in dollars per share) | $ / shares		$ 0.001			$ 0.001
Swire Pacific Offshore Holdings Ltd. [Member]
Number of Vessels, Offshore Support		50			50
Payments to Acquire Businesses, Gross		$ 42,000
Payments to Acquire Businesses, Preclosing Working Capital Adjustments		19,600
Proceeds From Previous Acquisition, Post-closing Working Capital Refund		8,800	$ 8,800
Business Combination, Consideration Transferred, Total		215,500
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual					$ 149,700
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					14,800
Proceeds From Previous Acquisition, Post-closing Working Capital Refund, in Excess of Original Estimate			$ 8,000
Business Combination, Acquisition Related Costs				3,000	18,800
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		174,415		$ 174,400
Property, Plant and Equipment, Original Lie of Asset (Year)				20 years
Goodwill, Ending Balance		$ 0
Business Acquisition, Pro Forma Revenue					714,783	578,506
Business Acquisition, Pro Forma Net Income (Loss)					$ (22,899)	$ (143,509)
Swire Pacific Offshore Holdings Ltd. [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)				1 year
Swire Pacific Offshore Holdings Ltd. [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)				16 years
Swire Pacific Offshore Holdings Ltd. [Member] | Warrants Issued to Acquire Swire Pacific Offshore Holdings Ltd. [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares		8,100,000			8,100,000
Sonatide [Member]
Payments to Acquire Businesses, Gross					$ 11,200
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual					2,300
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual					$ 800
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage						49.00%
Equity Method Investment, Ownership Percentage by Other Owners						51.00%
Business Acquisition, Percentage of Voting Interests Acquired					51.00%
Business Combination, Bargain Purchase, Gain Recognized, Amount					$ 1,300
Business Acquisition, Pro Forma Revenue						$ 375,400
Business Acquisition, Pro Forma Net Income (Loss)						$ 129,900
Sonatide [Member] | Interest Income and Other, Net [Member]
Business Combination, Bargain Purchase, Gain Recognized, Amount					$ 1,300
Unsecured Debt [Member]
Debt Instrument, Interest Rate, Stated Percentage				10.375%			10.375%
Vessels From Solstad Offshore ASA [Member]
Number of Platform Support Vessels	37
Payments to Acquire Productive Assets	$ 594,200
Payments to Acquire Productive Assets, Gross, Before Adjustments	577,000
Asset Acquisition, Provisional Information, Initial Accounting Incomplete, Adjustment, Purchase Price	3,000
Asset Acquisition, Provisional Information, Initial Accounting Incomplete, Adjustment, Working Capital	3,200
Asset Acquisition, Acquisition Related Costs	11,000
Vessels From Solstad Offshore ASA [Member] | Lubricants [Member]
Asset Acquisition, Provisional Information, Initial Accounting Incomplete, Adjustment, Working Capital	$ 1,300