CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	GulfMark	Common Stock	Common Stock GulfMark	Additional paid- in capital	Additional paid- in capital GulfMark	Retained earnings (deficit)	Accumulated other comprehensive income (loss)	Non controlling interest
Balance at Mar. 31, 2017	$ 1,637,644		$ 4,712		$ 165,221		$ 1,461,914	$ (10,344)	$ 16,141
Total comprehensive loss	(1,649,344)						(1,646,909)	(2,435)
Stock option expense	390				390
Cancellation/forfeiture of restricted stock units	1,254				1,254
Amortization of restricted stock units	2				2
Cash paid to noncontrolling interests	(1,200)								(1,200)
Balance at Jul. 31, 2017	(11,254)		4,712		166,867		(184,995)	(12,779)	14,941
Cancellation of Predecessor equity	12,929		(4,712)		(166,867)		184,995	12,779	(13,266)
Balance at Jul. 31, 2017	1,675								1,675
Balance at Jul. 31, 2017	1,057,084		18		1,055,391			(12,779)	1,675
Issuance of Successor common stock and warrants	1,055,409		18		1,055,391
Total comprehensive loss	(38,873)						(39,266)	(147)	540
Issuance of common stock	2		4		(2)
Amortization/cancellation of restricted stock units	3,731				3,731
Balance at Dec. 31, 2017	1,021,944		22		1,059,120		(39,266)	(147)	2,215
Total comprehensive loss	(169,430)						(171,517)	2,341	(254)
Issuance of common stock		$ 285,492		$ 9		$ 285,483
Issuance of common stock from exercise of warrants	3		6		(3)
Amortization of restricted stock units	8,914				8,914
Cash paid to noncontrolling interests	(2,000)				(1,126)				(874)
Balance at Dec. 31, 2018	1,087
Balance at Dec. 31, 2018	1,144,923		37		1,352,388		(210,783)	2,194	1,087
Total comprehensive loss	(143,649)						(141,743)	(2,430)	524
Issuance of common stock from exercise of warrants			3		(3)
Amortization of restricted stock units	15,136				15,136
Balance at Dec. 31, 2019	1,611
Balance at Dec. 31, 2019	$ 1,016,410		$ 40		$ 1,367,521		$ (352,526)	$ (236)	$ 1,611