Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income (Loss)	$ 6,011	$ (19,992)
Other Comprehensive Income (Loss):
Foreign currency translation gains (losses)	4,392	(2,528)
Derivative gains (losses) on cash flows hedges	127	(2,038)
Other comprehensive income (loss)	4,656	(4,519)
Comprehensive Income (Loss)	10,667	(24,511)
Comprehensive Income (Loss) Attributable to Noncontrolling Interests in Subsidiaries		(4,047)
Comprehensive Income (Loss) attributable to SEACOR Marine Holdings Inc.	10,667	(20,464)
Interest Expense
Other Comprehensive Income (Loss):
Reclassification of derivative losses on cash flow hedges	415	196
Equity Method Investments1
Other Comprehensive Income (Loss):
Reclassification of derivative losses on cash flow hedges	$ (278)	$ (149)