Equipment Acquisitions and Dispositions - Schedule of Vessel Acquired and Disposed (Details)		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Property Plant And Equipment [Line Items]
Acquired		1	[1]	4	[2]	4
Removed from service		5	[3]	10	[4]	14
Fast Support Vessels
Property Plant And Equipment [Line Items]
Acquired						2
Removed from service		3	[3]	4	[4]	5
Offshore Support Vessels, Supply
Property Plant And Equipment [Line Items]
Acquired		1	[1]	4	[2]	2
Removed from service		1	[3]	1	[4]	5
Anchor Handling Towing Supply
Property Plant And Equipment [Line Items]
Removed from service				2	[4]	1
Offshore Support Vessels, Liftboats
Property Plant And Equipment [Line Items]
Removed from service		1	[3]	1	[4]	3
Specialty Vessel
Property Plant And Equipment [Line Items]
Removed from service	[4]			2

[1] Excludes five PSVs acquired as part of the OSV Partners Acquisition (see “Note 3. Business Acquisitions”).

[2] Excludes three CTVs as assets held for sale and seven PSVs acquired as part of the SEACOSCO Acquisition (see “Note 3. Business Acquisitions”).

[3] Excludes four liftboats that were previously removed from service.

[4] Excludes three vessels that were previously removed from service (two AHTS vessels and one specialty vessel).