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Exploration Contracts (Details) - Allseas Group S.A - USD ($) shares in Millions, $ in Millions			3 Months Ended			9 Months Ended		12 Months Ended
	Nov. 09, 2022	Apr. 25, 2022	Dec. 31, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Amount of expenses				$ 1.3	$ 12.9	$ 4.0	$ 12.9
Owned common shares (in shares)				22.7		22.7		16.2
Common shares outstanding, percentage						8.60%		7.20%
PMTS
Finite-Lived Intangible Assets [Line Items]
Payment	$ 10.0
PMTA
Finite-Lived Intangible Assets [Line Items]
Payment		$ 10.0
Completion of the PMTS
Finite-Lived Intangible Assets [Line Items]
Amount payable			$ 10.0

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