SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ (162,919)	$ (143,430)	$ (332,007)	$ (175,227)
Currency translation adjustments	(12,334)	(7,967)	4,565	(37,000)
Unrealized gain on cash flow hedges	1,124	(98)	1,598	1,250
Total comprehensive loss	(174,129)	(151,495)	(325,844)	(210,977)
Net income attributable to noncontrolling interests	(55)	(517)	(213)	(584)
Currency translation adjustments attributable to noncontrolling interests	35	(32)	24	(171)
Total comprehensive (income) loss attributable to noncontrolling interests	(20)	(549)	(189)	(755)
Total comprehensive loss attributable to Bristow Group	(174,149)	(152,044)	(326,033)	(211,732)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	103,132	123,744	204,089	130,809
Currency translation adjustments	3,822	6,498	6,763	60,153
Unrealized gain on cash flow hedges	0	0	0	0
Total comprehensive loss	106,954	130,242	210,852	190,962
Net income attributable to noncontrolling interests	0	0	0	0
Currency translation adjustments attributable to noncontrolling interests	0	0	0	0
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Total comprehensive loss attributable to Bristow Group	106,954	130,242	210,852	190,962
Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(162,963)	(143,934)	(332,194)	(175,783)
Currency translation adjustments	0	0	0	0
Unrealized gain on cash flow hedges	0	0	0	0
Total comprehensive loss	(162,963)	(143,934)	(332,194)	(175,783)
Net income attributable to noncontrolling interests	(11)	(13)	(26)	(28)
Currency translation adjustments attributable to noncontrolling interests	0	0	0	0
Total comprehensive (income) loss attributable to noncontrolling interests	(11)	(13)	(26)	(28)
Total comprehensive loss attributable to Bristow Group	(162,974)	(143,947)	(332,220)	(175,811)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(77,526)	(94,186)	(111,332)	(103,452)
Currency translation adjustments	0	(159)	(355)	(1,045)
Unrealized gain on cash flow hedges	0	0	0	0
Total comprehensive loss	(77,526)	(94,345)	(111,687)	(104,497)
Net income attributable to noncontrolling interests	0	0	0	0
Currency translation adjustments attributable to noncontrolling interests	0	0	0	0
Total comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Total comprehensive loss attributable to Bristow Group	(77,526)	(94,345)	(111,687)	(104,497)
Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(25,562)	(29,054)	(92,570)	(26,801)
Currency translation adjustments	(16,156)	(14,306)	(1,843)	(96,108)
Unrealized gain on cash flow hedges	1,124	(98)	1,598	1,250
Total comprehensive loss	(40,594)	(43,458)	(92,815)	(121,659)
Net income attributable to noncontrolling interests	(44)	(504)	(187)	(556)
Currency translation adjustments attributable to noncontrolling interests	35	(32)	24	(171)
Total comprehensive (income) loss attributable to noncontrolling interests	(9)	(536)	(163)	(727)
Total comprehensive loss attributable to Bristow Group	$ (40,603)	$ (43,994)	$ (92,978)	$ (122,386)