VARIABLE INTEREST ENTITIES (Details) £ / shares in Units, $ in Thousands, £ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Apr. 30, 2015	Jul. 31, 2014	Jun. 30, 2017 USD ($) Affiliates Nominations	Jun. 30, 2016 USD ($)	Dec. 31, 2013	Jun. 30, 2017 GBP (£) Class_Of_Shares voting_rights	Jun. 30, 2017 USD ($) Class_Of_Shares voting_rights	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	May 31, 2004 USD ($) shares	May 31, 2004 £ / shares	Apr. 30, 2004
Variable Interest Entities [Line Items]
Deferred taxes							$ 0	$ 830
Number of variable interest entities | Affiliates			4
Deferred interest expense							5,702	12,909
Cash and cash equivalents				$ 122,711			78,879	96,656	$ 104,310
Accounts receivable							231,715	206,915
Inventories							130,479	124,911
Prepaid expenses and other current assets							43,145	41,143
Assets, Current							518,803	507,871
Investment in unconsolidated affiliates							205,174	210,162
Total property and equipment, net							2,211,025	2,254,364
Goodwill							19,907	19,798
Other assets							115,921	121,652
Total assets							3,070,830	3,113,847
Accounts payable							96,498	98,215
Accrued liabilities							179,497	186,246
Accrued interest							5,702	12,909
Current maturities of long-term debt							117,817	131,063
Total current liabilities							393,812	416,354
Total long-term debt							1,174,749	1,150,956
Accrued pension liabilities							60,057	61,647
Other liabilities and deferred credits							25,634	28,899
Deferred taxes							159,439	154,873
Redeemable noncontrolling interest							$ 6,349	6,886
Revenues			$ 352,109	369,398
Net income (loss)			$ (55,746)	(41,072)
Caledonia Investments Plc [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage, Third Party			46.00%
European Union [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage, Third Party			5.00%
Nigerian Company owned by 100% Nigerian Employees [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage, Third Party			50.00%
Variable Interest Entity, Qualitative or Quantitative Information, Purchased Percentage From Third Party	2.00%	29.00%			19.00%
Employee Trust Fund [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage, Third Party			2.00%
Bristow Aviation Holdings Limited [Member]
Variable Interest Entities [Line Items]
Ownership percentage in Variable Interest Entity			49.00%
Class Of Shares, Number | Class_Of_Shares						3	3
Variable Interest Entity, Qualitative or Quantitative Information, 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 expense							$ 1,945,668	1,891,305
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%
Cash and cash equivalents							$ 71,364	92,409
Accounts receivable							233,627	222,560
Inventories							96,646	90,190
Prepaid expenses and other current assets							42,548	50,016
Assets, Current							444,185	455,175
Investment in unconsolidated affiliates							3,531	3,513
Total property and equipment, net							315,403	306,831
Goodwill							19,907	19,798
Other assets							207,268	203,228
Total assets							990,294	988,545
Accounts payable							184,308	146,841
Accrued liabilities							129,699	122,130
Accrued interest							1,945,668	1,891,305
Current maturities of long-term debt							18,821	18,578
Total current liabilities							2,278,496	2,178,854
Total long-term debt							477,781	501,782
Accrued pension liabilities							60,057	61,647
Other liabilities and deferred credits							8,005	8,138
Deferred taxes							15,767	20,264
Redeemable noncontrolling interest							6,349	6,886
Liabilities							$ 2,846,455	$ 2,777,571
Revenues			$ 301,970	318,454
Operating loss			(19,654)	(19,743)
Net income (loss)			$ (79,169)	$ (88,543)
Bristow Aviation Holdings Limited [Member] | Caledonia Investments Plc [Member]
Variable Interest Entities [Line Items]
Number Of Voting Rights | voting_rights						3	3
Number of Board Of Directors Nomination | Nominations			2
Bristow Aviation Holdings Limited [Member] | Director [Member]
Variable Interest Entities [Line Items]
Number Of Voting Rights | voting_rights						1	1
Bristow Aviation Holdings Limited [Member] | Director Two [Member]
Variable Interest Entities [Line Items]
Number Of Voting Rights | voting_rights						1	1
Bristow Helicopters Nigeria Ltd [Member]
Variable Interest Entities [Line Items]
Ownership percentage in Variable Interest Entity			48.00%
Variable Interest Entity, Qualitative or Quantitative Information, Purchased Percentage From Third Party	8.00%
Pan African Airlines Nigeria Ltd [Member]
Variable Interest Entities [Line Items]
Ownership percentage in Variable Interest Entity			50.17%