TAXES (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015 USD ($)	Mar. 31, 2017 USD ($) aircraft	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Nov. 01, 2015	Jan. 29, 2015
Components of Deferred Tax Assets and Liabilities [Line Items]
Goodwill, impairment loss	$ 22,300	$ 8,706	$ 41,579
Foreign tax credit carryback, maximum, period		1 year
Foreign tax credit carryforward, maximum, period		10 years
Cash tax refunds received		$ 27,700
Unused Losses		1,600
Increase (decrease) in valuation allowance		$ 37,000
Number of aircraft involved in intercompany leasing transaction | aircraft		11
Remaining useful life of an intercompany leasing transaction		13 years
Tax benefit from intercompany leasing transaction		$ 2,400	2,800	$ 2,900
Unrecognized tax benefits period increase decrease		200	400	500
Interest and penalties		200	300	400
Unremitted foreign earnings reinvested abroad		717,100	832,100
Tax benefit attributable to options exercised		0	0	1,600
Income taxes paid		28,100	28,000	34,800
Deferred tax assets:
Deferred tax assets - foreign tax credits		39,554	41,140
Deferred tax assets - state net operating loss		8,432	0
Deferred tax assets - net operating loss		97,878	28,695
Deferred tax assets - accrued pension liability		10,445	13,266
Deferred tax assets - accrued equity compensation		17,162	17,092
Deferred tax assets - deferred revenues		1,446	1,749
Deferred tax assets, employee award programs		4,343	5,098
Deferred tax assets - employee payroll accruals		5,328	5,099
Deferred tax assets, inventories		3,111	3,305
Deferred tax assets, investment in unconsolidated affiliates		17,099	10,863
Deferred tax assets - other		5,865	4,903
Total deferred tax assets		135,936	101,837
Deferred tax liabilities:
Deferred tax liabilities- property and equipment		(220,305)	(202,388)
Deferred tax liabilities- inventories		(1,967)	(799)
Deferred tax liabilities- investments in unconsolidated affiliates		(28,631)	(38)
Deferred tax liabilities - employee programs		(1,033)	(1,360)
Deferred tax liabilities, deferred gain		(3,208)	0
Deferred tax liabilities- other		(5,371)	(3,390)
Total deferred tax liabilities		(260,515)	(207,975)
Net deferred tax liabilities		(124,579)	(106,138)
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Domestic		(147,988)	(115,277)	(40,602)
Foreign		3,686	36,046	152,075
Income (loss) before provision for income taxes		(144,302)	(79,231)	111,473
Effective income tax rate reconciliation, amount
Current domestic provision for income taxes		2,797	(29,907)	4
Current foreign provision for income taxes		17,153	27,317	34,822
Current provision for income taxes total		19,950	(2,590)	34,826
Deferred domestic provision for income taxes		24,651	(4,483)	(11,358)
Deferred foreign provision for income taxes		(12,013)	4,991	(702)
Deferred Income Tax Expense (Benefit), Total		12,638	508	(12,060)
Income Tax Expense (Benefit)		$ 32,588	$ (2,082)	$ 22,766
Effective income tax rate reconciliation, tax contingency, percent
Statutory rate		35.00%	35.00%	35.00%
Net foreign taxes on non-U.S. earnings		(0.50%)	(8.40%)	26.30%
Benefit of foreign tax deduction in the U.S.		2.50%	2.60%	0.00%
Foreign earnings indefinitely reinvested abroad		(1.10%)	15.90%	(47.00%)
Change in valuation allowance		(25.70%)	(25.30%)	4.00%
Foreign earnings that are currently taxed in the U.S.		(28.30%)	(7.90%)	8.70%
Effect of reduction in U.K. corporate income tax rate		(0.20%)	1.10%	0.00%
Goodwill impairment		(1.00%)	(11.80%)	0.00%
Benefit of current year foreign tax credits		0.00%	0.00%	(11.30%)
Tax reserve release		0.60%	0.20%	(0.10%)
Other, net		(3.90%)	1.20%	4.80%
Effective Tax Rate Total		(22.60%)	2.60%	20.40%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits- beginning balance		$ 1,093	$ 4,904
Pre-acquisition tax liability		0	(4,193)
Increase for tax positions taken in prior years		1,059	898
Decreases for tax positions taken in prior years		(818)	(188)
Decrease related to settlements with authorities		(2)	(328)
Unrecognized tax benefits- ending balance		$ 1,332	1,093	$ 4,904
United States
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2014
U.K.
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2016
Nigeria
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2009
Trinidad
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2005
Australia
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2013
Norway
Components of Deferred Tax Assets and Liabilities [Line Items]
Open tax years by jurisdiction		2014
Year 2021
Deferred tax assets:
Deferred tax assets - foreign tax credits		$ 6,600
Year 2022
Deferred tax assets:
Deferred tax assets - foreign tax credits		4,000
Year 2023
Deferred tax assets:
Deferred tax assets - foreign tax credits		200
Year 2024
Deferred tax assets:
Deferred tax assets - foreign tax credits		15,600
Year 2025
Deferred tax assets:
Deferred tax assets - foreign tax credits		13,200
Year 2037
Deferred tax assets:
Deferred tax assets - foreign tax credits		124,700
Valuation Allowance of Deferred Tax Assets
Components of Deferred Tax Assets and Liabilities [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		37,000
Domestic tax authority
Components of Deferred Tax Assets and Liabilities [Line Items]
Net operating loss		123,200
Deferred tax assets, valuation allowance		(34,321)	(29,373)
Deferred tax assets:
Deferred tax assets, valuation allowance		(34,321)	(29,373)
Foreign tax authority
Components of Deferred Tax Assets and Liabilities [Line Items]
Deferred tax assets, valuation allowance		(31,974)	0
Deferred tax assets:
Deferred tax assets, valuation allowance		(31,974)	0
State and local jurisdiction
Components of Deferred Tax Assets and Liabilities [Line Items]
Deferred tax assets, valuation allowance		(8,432)	0
Deferred tax assets:
Deferred tax assets, valuation allowance		$ (8,432)	$ 0
Eastern Airways
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Pre-acquisition tax liability				$ (4,200)
Airnorth
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Business acquisition, percentage of voting interests acquired					15.00%	85.00%