SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 350,657	$ 373,676	$ 718,551	$ 725,785
Direct cost and reimbursable expense	292,411	300,156	588,366	597,962
Intercompany expenses	0	0	0	0
Depreciation and amortization	30,489	31,381	61,430	62,437
General and administrative	38,839	48,622	78,940	95,329
Operating expense	361,739	380,159	728,736	755,728
Loss on impairment	(117,220)	0	(117,220)	(1,192)
Gain (loss) on disposal of assets	(1,293)	(8,526)	(2,971)	(7,827)
Earnings from unconsolidated affiliates, net of losses	(96)	2,063	(3,113)	1,398
Operating loss	(129,691)	(12,946)	(133,489)	(37,564)
Interest expense, net	(26,433)	(18,563)	(53,577)	(34,584)
Other income (expense), net	(3,204)	2,587	(7,154)	971
Loss before benefit (provision) for income taxes	(159,328)	(28,922)	(194,220)	(71,177)
Benefit (provision) for income taxes	15,655	(2,474)	18,506	(15,965)
Net loss	(143,673)	(31,396)	(175,714)	(87,142)
Net (income) loss attributable to noncontrolling interests	(517)	187	(584)	658
Net loss attributable to Bristow Group	(144,190)	(31,209)	(176,298)	(86,484)
External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	350,657	373,676	718,551	725,785
Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue	(27,496)	(31,719)	(54,013)	(63,910)
Direct cost and reimbursable expense	0	0	0	0
Intercompany expenses	(27,496)	(31,719)	(54,013)	(63,910)
Depreciation and amortization	0	0	0	0
General and administrative	0	0	0	0
Operating expense	(27,496)	(31,719)	(54,013)	(63,910)
Loss on impairment	0		0	0
Gain (loss) on disposal of assets	0	0	0	0
Earnings from unconsolidated affiliates, net of losses	123,987	(9,642)	131,296	11,003
Operating loss	123,987	(9,642)	131,296	11,003
Interest expense, net	0	0	0	0
Other income (expense), net	0	0	0	0
Loss before benefit (provision) for income taxes	123,987	(9,642)	131,296	11,003
Benefit (provision) for income taxes	0	0	0	0
Net loss	123,987	(9,642)	131,296	11,003
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net loss attributable to Bristow Group	123,987	(9,642)	131,296	11,003
Eliminations | External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
Eliminations | Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	(27,496)	(31,719)	(54,013)	(63,910)
Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Revenue	45	0	90	0
Direct cost and reimbursable expense	20	3,263	36	3,269
Intercompany expenses	15,307	0	15,307	0
Depreciation and amortization	3,092	3,016	6,158	5,933
General and administrative	12,907	17,880	25,695	36,987
Operating expense	31,326	24,159	47,196	46,189
Loss on impairment	0		0	0
Gain (loss) on disposal of assets	0	0	(806)	0
Earnings from unconsolidated affiliates, net of losses	(123,987)	9,642	(131,296)	(11,003)
Operating loss	(155,268)	(14,517)	(179,208)	(57,192)
Interest expense, net	(15,564)	(10,636)	(31,943)	(19,694)
Other income (expense), net	50	(97)	184	(126)
Loss before benefit (provision) for income taxes	(170,782)	(25,250)	(210,967)	(77,012)
Benefit (provision) for income taxes	26,605	(5,946)	34,697	(9,448)
Net loss	(144,177)	(31,196)	(176,270)	(86,460)
Net (income) loss attributable to noncontrolling interests	(13)	(13)	(28)	(24)
Net loss attributable to Bristow Group	(144,190)	(31,209)	(176,298)	(86,484)
Parent Company Only | External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	45	0	90	0
Parent Company Only | Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	0	0	0	0
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	64,294	78,671	124,946	156,637
Direct cost and reimbursable expense	40,981	45,955	82,857	98,289
Intercompany expenses	0	0	0	0
Depreciation and amortization	17,733	13,237	35,955	25,720
General and administrative	5,125	5,623	8,923	11,385
Operating expense	63,839	64,815	127,735	135,394
Loss on impairment	(87,474)		(87,474)	(1,192)
Gain (loss) on disposal of assets	(318)	10,597	(1,478)	11,013
Earnings from unconsolidated affiliates, net of losses	0	0	0	0
Operating loss	(87,337)	24,453	(91,741)	31,064
Interest expense, net	(5,915)	(6,023)	(12,745)	(11,803)
Other income (expense), net	242	(399)	1,317	(756)
Loss before benefit (provision) for income taxes	(93,010)	18,031	(103,169)	18,505
Benefit (provision) for income taxes	(1,176)	(1,945)	(283)	(6,105)
Net loss	(94,186)	16,086	(103,452)	12,400
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Net loss attributable to Bristow Group	(94,186)	16,086	(103,452)	12,400
Guarantor Subsidiaries | External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	36,798	46,952	70,933	92,727
Guarantor Subsidiaries | Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	27,496	31,719	54,013	63,910
Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue	313,814	326,724	647,528	633,058
Direct cost and reimbursable expense	251,410	250,938	505,473	496,404
Intercompany expenses	12,189	31,719	38,706	63,910
Depreciation and amortization	9,664	15,128	19,317	30,784
General and administrative	20,807	25,119	44,322	46,957
Operating expense	294,070	322,904	607,818	638,055
Loss on impairment	(29,746)		(29,746)	0
Gain (loss) on disposal of assets	(975)	(19,123)	(687)	(18,840)
Earnings from unconsolidated affiliates, net of losses	(96)	2,063	(3,113)	1,398
Operating loss	(11,073)	(13,240)	6,164	(22,439)
Interest expense, net	(4,954)	(1,904)	(8,889)	(3,087)
Other income (expense), net	(3,496)	3,083	(8,655)	1,853
Loss before benefit (provision) for income taxes	(19,523)	(12,061)	(11,380)	(23,673)
Benefit (provision) for income taxes	(9,774)	5,417	(15,908)	(412)
Net loss	(29,297)	(6,644)	(27,288)	(24,085)
Net (income) loss attributable to noncontrolling interests	(504)	200	(556)	682
Net loss attributable to Bristow Group	(29,801)	(6,444)	(27,844)	(23,403)
Non- Guarantor Subsidiaries | External Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	313,814	326,724	647,528	633,058
Non- Guarantor Subsidiaries | Intercompany Customer
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0