SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Operations (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]
Revenue	$ 318,220	$ 349,343	$ 651,396	$ 716,011
Direct cost and reimbursable expense	249,495	292,411	523,388	588,366
Intercompany expenses	0	0	0	0
Prepetition restructuring charges	0	0	13,476	0
Depreciation and amortization	31,303	30,489	62,642	61,430
General and administrative	37,820	38,839	72,590	78,940
Operating expense	318,618	361,739	672,096	728,736
Loss on impairment	(62,101)	(117,220)	(62,101)	(117,220)
Gain (loss) on disposal of assets	(230)	(1,293)	(4,017)	(2,971)
Earnings from unconsolidated affiliates, net of losses	633	1,461	2,980	(86)
Operating loss	(62,096)	(129,448)	(83,838)	(133,002)
Interest expense, net	(22,445)	(26,433)	(48,766)	(53,577)
Reorganization items	(93,943)	0	(170,299)	0
Gain (loss) on sale of subsidiaries	420	0	(55,883)	0
Other expense, net	(6,637)	(3,204)	(10,510)	(7,154)
Loss before benefit (provision) for income taxes	(184,701)	(159,085)	(369,296)	(193,733)
Benefit for income taxes	21,782	15,655	37,289	18,506
Net income (loss)	(162,919)	(143,430)	(332,007)	(175,227)
Net (income) loss attributable to noncontrolling interests	(55)	(517)	(213)	(584)
Net loss attributable to Bristow Group	(162,974)	(143,947)	(332,220)	(175,811)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue	(22,416)	(27,496)	(47,093)	(54,013)
Direct cost and reimbursable expense	0	0	0	0
Intercompany expenses	(22,416)	(27,496)	(47,093)	(54,013)
Prepetition restructuring charges			0
Depreciation and amortization	0	0	0	0
General and administrative	0	0	0	0
Operating expense	(22,416)	(27,496)	(47,093)	(54,013)
Loss on impairment	0	0	0	0
Gain (loss) on disposal of assets	0	0	0	0
Earnings from unconsolidated affiliates, net of losses	103,132	123,744	204,089	130,809
Operating loss	103,132	123,744	204,089	130,809
Interest expense, net	0	0	0	0
Reorganization items	0
Gain (loss) on sale of subsidiaries	0		0
Other expense, net	0	0	0	0
Loss before benefit (provision) for income taxes	103,132	123,744	204,089	130,809
Benefit for income taxes	0	0	0	0
Net income (loss)	103,132	123,744	204,089	130,809
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net loss attributable to Bristow Group	103,132	123,744	204,089	130,809
Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Revenue	0	45	0	90
Direct cost and reimbursable expense	32	20	151	36
Intercompany expenses	0	15,307	0	15,307
Prepetition restructuring charges			12,449
Depreciation and amortization	3,192	3,092	6,329	6,158
General and administrative	15,967	12,907	25,678	25,695
Operating expense	19,191	31,326	44,607	47,196
Loss on impairment	0	0	0	0
Gain (loss) on disposal of assets	0	0	0	(806)
Earnings from unconsolidated affiliates, net of losses	(103,132)	(123,744)	(204,089)	(130,809)
Operating loss	(122,323)	(155,025)	(248,696)	(178,721)
Interest expense, net	(11,100)	(15,564)	(24,467)	(31,943)
Reorganization items	(56,589)		(106,434)
Gain (loss) on sale of subsidiaries	0		0
Other expense, net	244	50	363	184
Loss before benefit (provision) for income taxes	(189,768)	(170,539)	(379,234)	(210,480)
Benefit for income taxes	26,805	26,605	47,040	34,697
Net income (loss)	(162,963)	(143,934)	(332,194)	(175,783)
Net (income) loss attributable to noncontrolling interests	(11)	(13)	(26)	(28)
Net loss attributable to Bristow Group	(162,974)	(143,947)	(332,220)	(175,811)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	64,184	64,294	126,660	124,946
Direct cost and reimbursable expense	42,709	40,981	84,333	82,857
Intercompany expenses	0	0	0	0
Prepetition restructuring charges			0
Depreciation and amortization	17,970	17,733	35,631	35,955
General and administrative	3,949	5,125	7,879	8,923
Operating expense	64,628	63,839	127,843	127,735
Loss on impairment	(42,022)	(87,474)	(42,022)	(87,474)
Gain (loss) on disposal of assets	(377)	(318)	(853)	(1,478)
Earnings from unconsolidated affiliates, net of losses	0	0	0	0
Operating loss	(42,843)	(87,337)	(44,058)	(91,741)
Interest expense, net	(5,376)	(5,915)	(11,241)	(12,745)
Reorganization items	(28,552)		(54,603)
Gain (loss) on sale of subsidiaries	0		0
Other expense, net	758	242	1,259	1,317
Loss before benefit (provision) for income taxes	(76,013)	(93,010)	(108,643)	(103,169)
Benefit for income taxes	(1,513)	(1,176)	(2,689)	(283)
Net income (loss)	(77,526)	(94,186)	(111,332)	(103,452)
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net loss attributable to Bristow Group	(77,526)	(94,186)	(111,332)	(103,452)
Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	276,452	312,500	571,829	644,988
Direct cost and reimbursable expense	206,754	251,410	438,904	505,473
Intercompany expenses	22,416	12,189	47,093	38,706
Prepetition restructuring charges			1,027
Depreciation and amortization	10,141	9,664	20,682	19,317
General and administrative	17,904	20,807	39,033	44,322
Operating expense	257,215	294,070	546,739	607,818
Loss on impairment	(20,079)	(29,746)	(20,079)	(29,746)
Gain (loss) on disposal of assets	147	(975)	(3,164)	(687)
Earnings from unconsolidated affiliates, net of losses	633	1,461	2,980	(86)
Operating loss	(62)	(10,830)	4,827	6,651
Interest expense, net	(5,969)	(4,954)	(13,058)	(8,889)
Reorganization items	(8,802)		(9,262)
Gain (loss) on sale of subsidiaries	420		(55,883)
Other expense, net	(7,639)	(3,496)	(12,132)	(8,655)
Loss before benefit (provision) for income taxes	(22,052)	(19,280)	(85,508)	(10,893)
Benefit for income taxes	(3,510)	(9,774)	(7,062)	(15,908)
Net income (loss)	(25,562)	(29,054)	(92,570)	(26,801)
Net (income) loss attributable to noncontrolling interests	(44)	(504)	(187)	(556)
Net loss attributable to Bristow Group	(25,606)	(29,558)	(92,757)	(27,357)
External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	318,220	349,343	651,396	716,011
External Customer | Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
External Customer | Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Revenue	0	45	0	90
External Customer | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	41,768	36,798	79,567	70,933
External Customer | Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	276,452	312,500	571,829	644,988
Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
Intercompany Customer | Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue	(22,416)	(27,496)	(47,093)	(54,013)
Intercompany Customer | Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
Intercompany Customer | Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	22,416	27,496	47,093	54,013
Intercompany Customer | Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0