Property And Equipment - Gross Components Of Property And Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment	$ 3,068,755	$ 3,078,571
Vessels
Property, Plant and Equipment [Line Items]
Property and equipment	$ 2,383,245	2,406,089
Vessels | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Vessels | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Systems and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 345,093	337,913
Systems and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Systems and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
ROVs and Trenchers
Property, Plant and Equipment [Line Items]
Property and equipment	$ 261,417	252,753
ROVs and Trenchers | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
ROVs and Trenchers | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Buildings and Other
Property, Plant and Equipment [Line Items]
Property and equipment	$ 79,000	$ 81,816
Buildings and Other | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Buildings and Other | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	39 years