Basis of Presentation and Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability	$ 321,000	$ 2,627,000		$ 321,000	$ 3,307,000
Capitalized interest costs, including allowance for funds used during construction, total	0	200,000
Impairment of long-lived assets owned or leased in vessels	900,000	0
Equity method investment, other than temporary impairment	$ 0	$ 0
Effective income tax rate reconciliation, percent, total	10.56%
Class of warrant or right, exercise price of warrants or rights	$ 0.01
Incremental common shares attributable to conversion of debt securities, total	2,907,500	2,907,500
Prior Periods Adjustment
Basis Of Presentation And Accounting Policies [Line Items]
Incremental common shares attributable to conversion of debt securities, total			2,183,708
Convertible Senior Note
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	2,907,500	2,907,500
Restricted Stock
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,469,647	1,059,077
Employee Stock Option
Basis Of Presentation And Accounting Policies [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,029,365	1,120,541
Africa and Europe Segment
Basis Of Presentation And Accounting Policies [Line Items]
Carrying value of assets held for sale	$ 2,300,000
Offshore Support Vessels
Basis Of Presentation And Accounting Policies [Line Items]
Estimated useful life (Year)	20 years
Geographic Distribution, Domestic | Prepaid Charter Modification And Reservation
Basis Of Presentation And Accounting Policies [Line Items]
Contract with customer, liability	$ 300,000
Minimum
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	20.00%
Minimum | SEACOR Marine Foreign Holdings
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50.00%
Maximum
Basis Of Presentation And Accounting Policies [Line Items]
Equity method investment, ownership percentage	50.00%	50.00%
Accounting Standards Update 2020-10
Basis Of Presentation And Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2020-06
Basis Of Presentation And Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2022
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2019-12
Basis Of Presentation And Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, immaterial effect [true false]	true