Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 3,189	$ 5,861	$ 12,533	$ 35,930
Other Comprehensive Income (Loss):
Foreign currency translation gains (losses), net	198	(405)	(753)	(418)
Derivative gains (losses) on cash flow hedges	24	0	(1,031)	0
Other comprehensive income (loss)	222	(405)	(1,784)	(418)
Income tax benefit (expense)	(3)	0	3	(68)
Other comprehensive income (loss), net of tax	219	(405)	(1,781)	(486)
Comprehensive Income	3,408	5,456	10,752	35,444
Comprehensive Income (Loss) Attributable to Noncontrolling Interests in Subsidiaries	(1)	(544)	(8)	7,239
Comprehensive Income Attributable to SEACOR Holdings Inc.	$ 3,409	$ 6,000	$ 10,760	$ 28,205