SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Comprehensive Income (Loss) (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]
Net income (loss)	$ (143,673)	$ (31,396)	$ (175,714)	$ (87,142)
Currency translation adjustments	(7,967)	10,691	(37,000)	20,451
Unrealized gain on cash flow hedges	(98)	0	1,250	0
Total comprehensive loss	(151,738)	(20,705)	(211,464)	(66,691)
Net (income) loss attributable to noncontrolling interests	(517)	187	(584)	658
Currency translation adjustments attributable to noncontrolling interests	(32)	237	(171)	547
Total comprehensive (income) loss attributable to noncontrolling interests	(549)	424	(755)	1,205
Total comprehensive loss attributable to Bristow Group	(152,287)	(20,281)	(212,219)	(65,486)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	123,987	(9,642)	131,296	11,003
Currency translation adjustments	6,498	(3,833)	60,153	(8,763)
Unrealized gain on cash flow hedges	0		0
Total comprehensive loss	130,485	(13,475)	191,449	2,240
Net (income) loss 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	130,485	(13,475)	191,449	2,240
Parent Company Only
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(144,177)	(31,196)	(176,270)	(86,460)
Currency translation adjustments	0	0	0	0
Unrealized gain on cash flow hedges	0		0
Total comprehensive loss	(144,177)	(31,196)	(176,270)	(86,460)
Net (income) loss attributable to noncontrolling interests	(13)	(13)	(28)	(24)
Currency translation adjustments attributable to noncontrolling interests	0	0	0	0
Total comprehensive (income) loss attributable to noncontrolling interests	(13)	(13)	(28)	(24)
Total comprehensive loss attributable to Bristow Group	(144,190)	(31,209)	(176,298)	(86,484)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(94,186)	16,086	(103,452)	12,400
Currency translation adjustments	(159)	306	(1,045)	644
Unrealized gain on cash flow hedges	0		0
Total comprehensive loss	(94,345)	16,392	(104,497)	13,044
Net (income) loss 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	(94,345)	16,392	(104,497)	13,044
Non- Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	(29,297)	(6,644)	(27,288)	(24,085)
Currency translation adjustments	(14,306)	14,218	(96,108)	28,570
Unrealized gain on cash flow hedges	(98)		1,250
Total comprehensive loss	(43,701)	7,574	(122,146)	4,485
Net (income) loss attributable to noncontrolling interests	(504)	200	(556)	682
Currency translation adjustments attributable to noncontrolling interests	(32)	237	(171)	547
Total comprehensive (income) loss attributable to noncontrolling interests	(536)	437	(727)	1,229
Total comprehensive loss attributable to Bristow Group	$ (44,237)	$ 8,011	$ (122,873)	$ 5,714