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Note 4 - Indebtedness - Summary of Debt Outstanding (Details) (Parentheticals)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
The 8.00% Senior Secured Notes due August 2022 [Member]
Interest rate	8.00%	8.00%
Maturity date	Aug. 31, 2022	Aug. 31, 2022
NOK Denominated Notes Due May 2024 [Member] | Troms Offshore [Member]
Maturity date	May 31, 2024	May 31, 2024
NOK Denominated Notes Due January 2026 [Member] | Troms Offshore [Member]
Maturity date	Jan. 31, 2026	Jan. 31, 2026
USD Denominated Notes Due January 2027 [Member] | Troms Offshore [Member]
Maturity date	Jan. 31, 2027	Jan. 31, 2027
USD Denominated Notes Due April 2027 [Member] | Troms Offshore [Member]
Maturity date	Apr. 30, 2027	Apr. 30, 2027

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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