VARIABLE INTEREST ENTITIES (Details) £ / shares in Units, $ in Thousands, £ in Millions	1 Months Ended			3 Months Ended		6 Months Ended
	Apr. 30, 2015	Jul. 31, 2014	Dec. 31, 2013	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Affiliates People	Sep. 30, 2015 USD ($)	Sep. 30, 2016 GBP (£) voting_rights	Sep. 30, 2016 USD ($) voting_rights	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	May 31, 2004 USD ($) shares	May 31, 2004 £ / shares	Apr. 30, 2004
Variable Interest Entities And Other Investments [Line Items]
Number of variable interest entities | Affiliates						4
Statement of Financial Position [Abstract]
Cash and cash equivalents					$ 139,341		$ 139,341		$ 100,668	$ 104,310	$ 104,146
Accounts receivable									207,356	249,317
Inventories									126,973	142,503
Prepaid expenses and other current assets									50,510	53,183
Total current assets									525,845	593,096
Investment in unconsolidated affiliates									206,483	194,952
Property, plant and equipment, net									2,290,912	2,283,252
Goodwill									28,922	29,990
Other assets									145,934	161,655
Total assets									3,198,096	3,262,945
Accounts payable									110,650	96,966
Accrued liabilities									198,975	201,605
Accrued interest									11,884	11,985
Current Maturities of long-term debt									81,510	60,394
Total current liabilities									399,183	390,368
Total long-term debt									1,140,036	1,071,578
Accrued pension liabilities									55,036	70,107
Other liabilities and deferred credits									25,137	33,273
Deferred taxes									149,328	172,254
Redeemable noncontrolling interest									13,175	15,473
Revenue				$ 357,467	446,911	$ 726,865	913,907
Net loss				(30,107)	(45,680)	$ (71,179)	(47,309)
Nigerian Company owned by 100% Nigerian Employees
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, ownership percentage, third party						50.00%
Variable interest entity, purchased percentage from third party	2.00%
Employee Trust Fund
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, ownership percentage, third party						2.00%
Bristow Helicopters Nigeria Ltd
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, purchased percentage from third party	8.00%
Bristow Aviation Holdings Limited
Variable Interest Entities And Other Investments [Line Items]
Ownership percentage in Variable Interest Entity						49.00%
Variable interest entity, ownership percentage, third party						51.00%
Purchase of deferred stock shares | shares												8,000,000
Business acquisition share price | £ / shares													£ 1
Total amount paid for deferred shares												$ 14,400
Principal amount of subordinated unsecured loan stock								£ 91.0	$ 118,200
Interest rate on unsecured loan						13.50%
Deferred interest cost						$ 1,800,000
Call option price held by noncontrolling interest | £								£ 1.0
Call option rate over LIBOR								3.00%	3.00%
Call option guaranteed rate												12.00%
Put option guaranteed rate														10.00%
Statement of Financial Position [Abstract]
Cash and cash equivalents									$ 99,651	62,773
Accounts receivable									585,968	565,223
Inventories									91,371	102,738
Prepaid expenses and other current assets									60,718	53,776
Total current assets									837,708	784,510
Investment in unconsolidated affiliates									3,862	4,676
Property, plant and equipment, net									227,078	251,494
Goodwill									28,922	29,990
Other assets									75,369	82,443
Total assets									1,172,939	1,153,113
Accounts payable									638,959	521,563
Accrued liabilities									142,315	141,977
Accrued interest									1,830,005	1,698,360
Current Maturities of long-term debt									12,595	10,322
Total current liabilities									2,623,874	2,372,222
Total long-term debt									138,479	155,222
Accrued pension liabilities									55,036	70,107
Other liabilities and deferred credits									4,327	7,928
Deferred taxes									8,753	20,330
Redeemable noncontrolling interest									13,175	15,473
Total liabilities									$ 2,843,644	$ 2,641,282
Revenue				310,325	377,362	628,779	764,133
Operating loss				(20,773)	(9,829)	(40,516)	(27,573)
Net loss				$ (80,794)	$ (78,938)	$ (169,337)	$ (143,715)
Bristow Aviation Holdings Limited | Caledonia Investments Plc
Variable Interest Entities And Other Investments [Line Items]
Number of voting rights | voting_rights								3	3
Number of board of directors nominations | People						2
Bristow Aviation Holdings Limited | Director one
Variable Interest Entities And Other Investments [Line Items]
Number of voting rights | voting_rights								1	1
Bristow Aviation Holdings Limited | Director two
Variable Interest Entities And Other Investments [Line Items]
Number of voting rights | voting_rights								1	1
Bristow Aviation Holdings Limited | Caledonia Investments Plc
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, ownership percentage, third party						46.00%
Bristow Aviation Holdings Limited | European Union
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, ownership percentage, third party						5.00%
Bristow Helicopters Nigeria Ltd
Variable Interest Entities And Other Investments [Line Items]
Ownership percentage in Variable Interest Entity						48.00%
Nigerian Company owned by 100% Nigerian Employees
Variable Interest Entities And Other Investments [Line Items]
Variable interest entity, purchased percentage from third party		29.00%	19.00%
Pan African Airlines Nigeria Ltd
Variable Interest Entities And Other Investments [Line Items]
Ownership percentage in Variable Interest Entity						50.17%