VARIABLE INTEREST ENTITIES AND OTHER INVESTMENTS IN SIGNIFICANT AFFILIATES VIE Financials (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interests - beginning of fiscal year				$ 5,025					$ 5,025
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders									(49)	$ (49)	$ (55)
Net Income (Loss) Attributable to Noncontrolling Interest									(2,425)	(6,354)	(4,707)
Currency translation adjustments									25,927	(21,636)	(21,604)
Noncontrolling interests - end of fiscal year	$ 7,253				$ 5,025				7,253	5,025
Statement of Financial Position [Abstract]
Cash and cash equivalents	380,223				96,656				380,223	96,656	104,310	$ 104,146
Accounts receivable	246,980				206,915				246,980	206,915
Inventories	129,614				124,911				129,614	124,911
Prepaid expenses and other current assets	47,234				41,143				47,234	41,143
Total current assets	834,399				507,871				834,399	507,871
Investment in unconsolidated affiliates	126,170				210,162				126,170	210,162
Property and equipment	2,068,020				2,254,364				2,068,020	2,254,364
Goodwill	19,907				19,798				19,907	19,798	29,990
Other assets	116,506				121,652				116,506	121,652
Total assets	3,165,002				3,113,847				3,165,002	3,113,847
Accounts payable	101,270				98,215				101,270	98,215
Accrued Liabilities, Current	204,927				186,246				204,927	186,246
Accrued interest	16,345				12,909				16,345	12,909
Short-term borrowings and current maturities of long-term debt	56,700				131,063				56,700	131,063
Total current liabilities	362,897				416,354				362,897	416,354
Long-term debt, less current maturities	1,429,834				1,150,956				1,429,834	1,150,956
Accrued pension liabilities	37,034				61,647				37,034	61,647
Other liabilities and deferred credits	36,952				28,899				36,952	28,899
Deferred taxes					154,873					154,873
Redeemable Noncontrolling Interest - ending balance	0				6,886				0	6,886	15,473
Income Statement [Abstract]
Revenues	358,442	$ 360,735	$ 373,676	352,109	336,194	$ 337,443	$ 357,467	$ 369,398	1,444,962	1,400,502	1,715,513
Net loss									(198,083)	(176,890)	(77,149)
Bristow Aviation Holdings Limited
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interests - beginning of fiscal year				$ 1,226				$ 1,410	1,226	1,410	1,457
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders									(49)	(49)	(55)
Net Income (Loss) Attributable to Noncontrolling Interest									50	50	55
Currency translation adjustments									131	(185)	(47)
Noncontrolling interests - end of fiscal year	1,358				1,226				1,358	1,226	1,410
Statement of Financial Position [Abstract]
Cash and cash equivalents	90,788				92,409				90,788	92,409
Accounts receivable	256,735				222,560				256,735	222,560
Inventories	98,314				90,190				98,314	90,190
Prepaid expenses and other current assets	38,665				50,016				38,665	50,016
Total current assets	484,502				455,175				484,502	455,175
Investment in unconsolidated affiliates	3,608				3,513				3,608	3,513
Property and equipment	327,440				306,831				327,440	306,831
Goodwill	19,907				19,798				19,907	19,798
Other assets	231,884				203,228				231,884	203,228
Total assets	1,067,341				988,545				1,067,341	988,545
Accounts payable	292,893				146,841				292,893	146,841
Accrued Liabilities, Current	140,733				122,130				140,733	122,130
Accrued interest	2,130,433				1,891,305				2,130,433	1,891,305
Short-term borrowings and current maturities of long-term debt	23,125				18,578				23,125	18,578
Total current liabilities	2,587,184				2,178,854				2,587,184	2,178,854
Long-term debt, less current maturities	479,571				501,782				479,571	501,782
Accrued pension liabilities	37,034				61,647				37,034	61,647
Other liabilities and deferred credits	7,342				8,138				7,342	8,138
Deferred taxes	26,252				20,264				26,252	20,264
Redeemable Noncontrolling Interest - ending balance	0				6,886				0	6,886
Total Liabilities and Temporary Equity	$ 3,137,383				$ 2,777,571				3,137,383	2,777,571
Income Statement [Abstract]
Revenues									1,241,223	1,209,019	1,441,834
Operating Income (Loss)									(65,254)	(80,542)	(57,780)
Net loss									$ (322,752)	$ (279,159)	$ (279,309)