Strategic Alliance with Allseas and Affiliates - Development of Project Zero Offshore Nodule Collection System (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Strategic Alliance with Allseas and Affiliates
Exploration and evaluation expenses	$ 10,496	$ 12,403	$ 20,011	$ 30,526
Project Management Technology Services
Strategic Alliance with Allseas and Affiliates
Exploration and evaluation expenses	$ 900	$ 3,200	$ 3,200	$ 6,900