Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 5,861	$ 27,203	$ 35,930	$ 78,768
Other Comprehensive Income (Loss):
Foreign currency translation gains (losses), net	(405)	(76)	(418)	59
Reclassification of foreign currency translation losses to foreign currency gains (losses), net	0	(15)	0	(15)
Other comprehensive income (loss)	(405)	(61)	(418)	74
Income tax benefit (expense)	0	2	(68)	27
Other comprehensive income (loss), net of tax	(405)	(59)	(486)	101
Comprehensive Income	5,456	27,144	35,444	78,869
Comprehensive Income (Loss) Attributable to Noncontrolling Interests in Subsidiaries	(544)	10,136	7,239	15,934
Comprehensive Income Attributable to SEACOR Holdings Inc.	$ 6,000	$ 17,008	$ 28,205	$ 62,935