OPERATIONS, BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands, £ in Millions, AUD in Millions					1 Months Ended		3 Months Ended		9 Months Ended	12 Months Ended
	Jan. 29, 2015 USD ($)	Jan. 29, 2015 AUD	Nov. 21, 2014 USD ($)	Nov. 21, 2014 GBP (£)	Nov. 30, 2015 USD ($)	Nov. 30, 2015 AUD	Dec. 31, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2017 USD ($) aircraft Affiliates	Mar. 31, 2016 USD ($) aircraft	Mar. 31, 2015 USD ($) aircraft	Mar. 31, 2014 USD ($) aircraft	Mar. 31, 2017 USD ($) Customer	Mar. 31, 2016 USD ($)	Nov. 01, 2015	Sep. 29, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jan. 29, 2015 USD ($)
Valuation and Qualifying Accounts Disclosure [Line Items]
Impairment of inventories										$ 7,572	$ 5,439	$ 7,200
Dormant, obsolete and excess inventory														$ 56,400	$ 19,400			$ 19,100
Movement in Valuation Allowances and Reserves [Roll Forward]
Impairment of inventories										7,572	5,439	7,200
Property and equipment [Line Items]
Construction in progress within property and equipment														199,275	307,360
Impairment charges on assets held for sale										12,450	29,571	36,057
Goodwill [Line Items]
Goodwill									$ 29,990	29,990	75,628	75,628		19,798	29,990			75,628
Accumulated goodwill impairment loss									(42,155)	(42,155)	(576)	(576)		(50,861)	(42,155)			(576)
Goodwill, impairment loss								$ (22,300)		(8,706)	(41,579)
Goodwill [Roll Forward]
Goodwill, beginning balance									29,990	29,990	75,628
Purchase price adjustments to previously acquired goodwill											(4,161)
Goodwill, translation adjustments										(1,486)	102
Goodwill, impairment loss								(22,300)		(8,706)	(41,579)
Goodwill, ending balance										19,798	29,990	75,628
Accumulated goodwill impairment [Rollforward]:
Accumulated goodwill impairment loss, beginning balance									(42,155)	(42,155)	(576)
Goodwill, impairment loss								$ (22,300)		(8,706)	(41,579)
Accumulated goodwill impairment loss, ending balance										(50,861)	(42,155)	(576)
Other Intangible Assets [Line Items]
Impairments, intangible assets											8,086
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									27,858	27,858	28,306
Foreign currency translation										(646)	(448)
Intangible Assets, gross ending balance										27,212	27,858	28,306
Accumulated amortization of intangible assets- beginning balance									(20,379)	(20,379)	(10,091)
Impairments, intangible assets											(8,086)
Amortization expense										(1,097)	(2,202)
Accumulated amortization of intangible assets- ending balance										$ (21,476)	(20,379)	(10,091)
Weighted average remaining contractual life, in years										5 years 9 months
2018														837
2019														715
2020														442
2021														442
2022														442
Thereafter														2,858
Total														5,736
Other [Line Items]
Number of aircraft operated | aircraft										459
Deferred set-up costs, current														9,700	12,100
Amortization of other deferred charges										$ 16,900	10,000
Deferred tax assets, net, noncurrent														34,800	68,000
Deferred contract acquisition cost, non current														51,100	55,100
Foreign currency transaction gain/loss										(2,900)	(4,300)	(6,500)
Proceeds from sale of unconsolidated affiliates										0	0	4,185
Gain on sale of unconsolidated affiliates										0	0	3,921
Extinguishment of debt										0	0	(2,591)
Accretion of redeemable noncontrolling interests										0	$ 1,498	$ 0
Proceeds from assignment of aircraft purchase agreements													$ 106,100
Number Of Aircraft Assigned Future Payments | aircraft											(2)	(5)	7
Deferred Sale Leaseback Cumulative Progress Payments													$ 147,400
Completion of deferred sale leaseback											$ 75,800	$ 183,700
Removal of deferred sale leaseback advance											74,300	182,600
Unamortized debt issuance costs														11,345	8,917
Interest income										943	1,058	956
Interest expense										(50,862)	(35,186)	(30,310)
Interest expense, net										$ (49,919)	(34,128)	(29,354)
Current deferred taxes														100
Current tax liabilities														$ 800
All debt excluding Revolving Credit Facility
Other [Line Items]
Unamortized debt issuance costs															8,900
Senior Notes | Senior Notes Due 2022
Other [Line Items]
Extinguishment of debt												2,600
Direct cost
Goodwill [Roll Forward]
Purchase price adjustments to previously acquired goodwill											1,000
ATP Oil And Gas Corporation [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts receivable, recoveries											4,400
Allowance for doubtful accounts receivable, write-offs											500
Airnorth
Goodwill [Line Items]
Goodwill	$ 24,252																		$ 24,252
Goodwill [Roll Forward]
Goodwill, ending balance	24,252
Other [Line Items]
Accretion of redeemable noncontrolling interests											1,498
Business acquisition, percentage of voting interests acquired																15.00%			85.00%
Acquisition cost	$ 24,000	AUD 30.3			$ 5,300	AUD 7.3
Acquisition of noncontrolling interests											5,467
Redeemable non controlling interest, carrying amount, period increase (decrease)					(5,500)
Adjustments to additional paid in capital					$ 2,600
Goodwill
Goodwill [Roll Forward]
Purchase price adjustments to previously acquired goodwill											(4,200)
Prepaid expenses and other current assets
Goodwill [Roll Forward]
Purchase price adjustments to previously acquired goodwill											2,700
Deferred tax liabilities
Goodwill [Roll Forward]
Purchase price adjustments to previously acquired goodwill											3,100
Accrued maintenance
Goodwill [Roll Forward]
Purchase price adjustments to previously acquired goodwill											(3,600)
Eastern Airways
Goodwill [Line Items]
Goodwill, impairment loss							$ (8,700)		(8,700)		(13,100)
Goodwill [Roll Forward]
Goodwill, impairment loss							(8,700)		(8,700)		(13,100)
Accumulated goodwill impairment [Rollforward]:
Goodwill, impairment loss							$ (8,700)		(8,700)		(13,100)
Maximum | Aircraft
Property and equipment [Line Items]
Property and equipment useful life										15 years
Property and equipment salvage value percentage														50.00%
Maximum | Building
Property and equipment [Line Items]
Property and equipment useful life										30 years
Maximum | Other depreciable assets
Property and equipment [Line Items]
Property and equipment useful life										15 years
Minimum | Aircraft
Property and equipment [Line Items]
Property and equipment useful life										5 years
Property and equipment salvage value percentage														30.00%
Minimum | Building
Property and equipment [Line Items]
Property and equipment useful life										15 years
Minimum | Other depreciable assets
Property and equipment [Line Items]
Property and equipment useful life										3 years
Unconsolidated affiliates
Other [Line Items]
Number of aircraft operated | Affiliates										111
Foreign currency transaction gain/loss										$ (3,200)	(22,400)	(25,700)
Nigeria
Valuation and Qualifying Accounts Disclosure [Line Items]
Number of uncollectible customer | Customer														2
Australia
Valuation and Qualifying Accounts Disclosure [Line Items]
Number of uncollectible customer | Customer														1
Norway
Other [Line Items]
Number of client contracts | Customer														2
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance- beginning of fiscal year									5,562	5,562	859	5,074
Additional allowances										575	6,638	1,050
Write-offs										(1,639)	(1,935)	(5,265)
Balance- end of fiscal year										4,498	5,562	859	5,074
Inventory valuation
Valuation and Qualifying Accounts Disclosure [Line Items]
Impairment of inventories										7,572	5,439	7,167
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance- beginning of fiscal year									27,763	27,763	45,414	47,298
Impairment of inventories										7,572	5,439	7,167
Additional allowances										1,617	192	4,867
Write-offs										(14,635)	(22,428)	(10,125)
Foreign currency effects										(803)	(854)	(3,793)
Balance- end of fiscal year										21,514	27,763	45,414	$ 47,298
Europe Caspian
Goodwill [Line Items]
Goodwill									10,026	10,026	35,701	35,701		$ 0	10,026		$ 24,600	35,701
Accumulated goodwill impairment loss									(25,177)	(25,177)	0	0		(33,883)	(25,177)			0
Goodwill, impairment loss										(8,706)	(25,177)
Goodwill [Roll Forward]
Goodwill, beginning balance									10,026	10,026	35,701
Purchase price adjustments to previously acquired goodwill											(170)
Goodwill, translation adjustments										(1,320)	(328)
Goodwill, impairment loss										(8,706)	(25,177)
Goodwill, ending balance										0	10,026	35,701
Accumulated goodwill impairment [Rollforward]:
Accumulated goodwill impairment loss, beginning balance									(25,177)	(25,177)	0
Goodwill, impairment loss										(8,706)	(25,177)
Accumulated goodwill impairment loss, ending balance										(33,883)	(25,177)	0
Europe Caspian | Norway
Goodwill [Line Items]
Goodwill																	12,100
Africa
Goodwill [Line Items]
Goodwill									0	0	5,946	5,946		0	0		5,900	5,946
Accumulated goodwill impairment loss									(6,179)	(6,179)	0	0		(6,179)	(6,179)			0
Goodwill, impairment loss										0	(6,179)
Goodwill [Roll Forward]
Goodwill, beginning balance									0	0	5,946
Purchase price adjustments to previously acquired goodwill											0
Goodwill, translation adjustments										0	233
Goodwill, impairment loss										0	(6,179)
Goodwill, ending balance										0	0	5,946
Accumulated goodwill impairment [Rollforward]:
Accumulated goodwill impairment loss, beginning balance									(6,179)	(6,179)	0
Goodwill, impairment loss										0	(6,179)
Accumulated goodwill impairment loss, ending balance										(6,179)	(6,179)	0
Americas
Goodwill [Line Items]
Accumulated goodwill impairment loss									(576)	(576)	(576)	(576)		(576)	(576)			(576)
Goodwill, impairment loss										0	0
Goodwill [Roll Forward]
Goodwill, impairment loss										0	0
Accumulated goodwill impairment [Rollforward]:
Accumulated goodwill impairment loss, beginning balance									(576)	(576)	(576)
Goodwill, impairment loss										0	0
Accumulated goodwill impairment loss, ending balance										(576)	(576)	(576)
Asia Pacific
Goodwill [Line Items]
Goodwill									19,964	19,964	23,791	23,791		19,798	19,964		21,900	23,791
Goodwill, impairment loss										0	0
Goodwill [Roll Forward]
Goodwill, beginning balance									19,964	19,964	23,791
Purchase price adjustments to previously acquired goodwill											(3,991)
Goodwill, translation adjustments										(166)	164
Goodwill, impairment loss										0	0
Goodwill, ending balance										19,798	19,964	23,791
Accumulated goodwill impairment [Rollforward]:
Goodwill, impairment loss										0	0
Corporate and other
Goodwill [Line Items]
Goodwill									0	0	10,190	10,190		0	0		$ 10,200	10,190
Accumulated goodwill impairment loss									(10,223)	(10,223)	0	0		$ (10,223)	$ (10,223)			$ 0
Goodwill, impairment loss										0	(10,223)
Goodwill [Roll Forward]
Goodwill, beginning balance									0	0	10,190
Purchase price adjustments to previously acquired goodwill											0
Goodwill, translation adjustments										0	33
Goodwill, impairment loss										0	(10,223)
Goodwill, ending balance										0	0	10,190
Accumulated goodwill impairment [Rollforward]:
Accumulated goodwill impairment loss, beginning balance									(10,223)	(10,223)	0
Goodwill, impairment loss										0	(10,223)
Accumulated goodwill impairment loss, ending balance										(10,223)	(10,223)	0
Helideck Certification Agency (HCA)
Other [Line Items]
Equity investment ownership percentage													50.00%
Proceeds from sale of unconsolidated affiliates			$ 4,200	£ 2.7
Gain on sale of unconsolidated affiliates			$ 3,900
Client contracts
Other Intangible Assets [Line Items]
Impairments, intangible assets											0
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									8,170	8,170	8,165
Foreign currency translation										(1)	5
Intangible Assets, gross ending balance										8,169	8,170	8,165
Accumulated amortization of intangible assets- beginning balance									(8,062)	(8,062)	(7,399)
Impairments, intangible assets											0
Amortization expense										(93)	(663)
Accumulated amortization of intangible assets- ending balance										$ (8,155)	(8,062)	(7,399)
Weighted average remaining contractual life, in years										2 months 13 days
Client relationships
Other Intangible Assets [Line Items]
Impairments, intangible assets											8,086
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									12,779	$ 12,779	13,056
Foreign currency translation										(27)	(277)
Intangible Assets, gross ending balance										12,752	12,779	13,056
Accumulated amortization of intangible assets- beginning balance									(10,600)	(10,600)	(1,583)
Impairments, intangible assets											(8,086)
Amortization expense										(471)	(931)
Accumulated amortization of intangible assets- ending balance										$ (11,071)	(10,600)	(1,583)
Weighted average remaining contractual life, in years										4 years 7 months
Trade names and trademarks
Other Intangible Assets [Line Items]
Impairments, intangible assets											0
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									5,008	$ 5,008	5,148
Foreign currency translation										(525)	(140)
Intangible Assets, gross ending balance										4,483	5,008	5,148
Accumulated amortization of intangible assets- beginning balance									(636)	(636)	(323)
Impairments, intangible assets											0
Amortization expense										(272)	(313)
Accumulated amortization of intangible assets- ending balance										$ (908)	(636)	(323)
Weighted average remaining contractual life, in years										13 years 1 month
Internally developed software
Other Intangible Assets [Line Items]
Impairments, intangible assets											0
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									1,149	$ 1,149	1,179
Foreign currency translation										(87)	(30)
Intangible Assets, gross ending balance										1,062	1,149	1,179
Accumulated amortization of intangible assets- beginning balance									(480)	(480)	(244)
Impairments, intangible assets											0
Amortization expense										(205)	(236)
Accumulated amortization of intangible assets- ending balance										$ (685)	(480)	(244)
Weighted average remaining contractual life, in years										1 year 9 months
Licenses
Other Intangible Assets [Line Items]
Impairments, intangible assets											0
Finite-lived Intangible Assets [Roll Forward]
Intangible Assets, gross beginning balance									752	$ 752	758
Foreign currency translation										(6)	(6)
Intangible Assets, gross ending balance										746	752	758
Accumulated amortization of intangible assets- beginning balance									$ (601)	(601)	(542)
Impairments, intangible assets											0
Amortization expense										(56)	(59)
Accumulated amortization of intangible assets- ending balance										$ (657)	$ (601)	$ (542)
Weighted average remaining contractual life, in years										1 year 7 months