PROPERTY AND EQUIPMENT AND ASSETS HELD FOR SALE (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016 USD ($) aircraft	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) aircraft	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2016 USD ($) aircraft	Mar. 31, 2015 USD ($) aircraft	Mar. 31, 2014 USD ($) aircraft
Property and equipment [Line Items]
Number of aircraft delivered | aircraft									8	21	21
Capital expenditures									$ 372,375	$ 601,834	$ 628,613
Number of aircraft sold or disposed of | aircraft									35	44	46
Proceeds from asset dispositions									$ 60,035	$ 414,859	$ 289,951
Gain (loss) on disposal of assets	$ (6,800)	$ (2,200)	$ (14,000)	$ (7,700)	$ (10,300)	$ (26,300)	$ 100	$ 600	(30,693)	(35,849)	$ (722)
Impairment charges on assets held for sale									$ 29,571	$ 36,057
Number of aircraft sale leaseback | aircraft									3	14	14
Sale leaseback transaction, gross proceeds									$ 29,200	$ 380,700	$ 246,400
Accelerated depreciation									$ 28,655	$ 10,379
Number of aircraft movement into (out of) deferred sale leaseback advance | aircraft									(2)	(5)
Completion of deferred sale leaseback									$ 75,800	$ 183,700
Removal of deferred sale leaseback advance									$ 74,300	182,600
Number of aircraft purchased with short-term borrowings | aircraft									2
Aircraft purchases with short-term borrowings									$ 24,394	0	0
Inventories	$ 142,503				$ 147,169				$ 142,503	$ 147,169	11,100
Number of aircraft transferred to held for sale | aircraft	35				15				35	15
Property and equipment, gross, period increase (decrease)									$ (83,600)	$ (91,500)
Proceeds from assignment of aircraft purchase agreements									0	0	$ 106,113
Number of aircraft assigned future payments | aircraft											7
Deferred sale leaseback advance									18,285	69,680	$ 60,194
Assets held for sale	$ 43,783				$ 57,827				43,783	57,827
Improper capitalization of profit | Revenue
Property and equipment [Line Items]
Quantifying misstatement in current year financial statements, amount										(3,500)
Improper capitalization of profit | Direct cost
Property and equipment [Line Items]
Quantifying misstatement in current year financial statements, amount										2,000
Improper capitalization of profit | Depreciation and amortization
Property and equipment [Line Items]
Quantifying misstatement in current year financial statements, amount										(200)
Improper capitalization of profit | Property, plant and equipment, net
Property and equipment [Line Items]
Quantifying misstatement in current year financial statements, amount										(4,400)
Improper capitalization of profit | Long-term liabilities
Property and equipment [Line Items]
Quantifying misstatement in current year financial statements, amount										900
Damage from fire, explosion or other hazard
Property and equipment [Line Items]
Number of aircraft sold or disposed of | aircraft											2
Gain (loss) on disposal of assets										4,900	$ (11,100)
Insurance recoveries										16,000	11,100
Africa and Americas
Property and equipment [Line Items]
Accelerated depreciation										4,400
Asia Pacific
Property and equipment [Line Items]
Capital expenditures									23,745	23,077	$ 7,058
Accelerated depreciation									$ 5,300	$ 6,000
Number of aircraft in exit plan | aircraft										4
Assets held for sale
Property and equipment [Line Items]
Number of aircraft impaired | aircraft									16	27	11
Impairment charges on assets held for sale									$ 29,571	$ 36,057	$ 6,814
Number of aircraft | aircraft									22	12
Medium aircraft
Property and equipment [Line Items]
Number of aircraft delivered | aircraft									1	6	8
Number of aircraft in exit plan | aircraft									18
Medium aircraft | Africa and Americas
Property and equipment [Line Items]
Number of aircraft in exit plan | aircraft										10
Large aircraft
Property and equipment [Line Items]
Number of aircraft delivered | aircraft									3	10	11
Number of aircraft in exit plan | aircraft									4
SAR aircraft
Property and equipment [Line Items]
Number of aircraft delivered | aircraft									4	5	2
Prototype aircraft
Property and equipment [Line Items]
Number of aircraft impaired | aircraft										3
Impairment charges on assets held for sale										$ 4,300
Fixed wing aircraft
Property and equipment [Line Items]
Number of aircraft in exit plan | aircraft									1
Fixed wing aircraft | Africa and Americas
Property and equipment [Line Items]
Number of aircraft in exit plan | aircraft										1
Aircraft and related equipment
Property and equipment [Line Items]
Capital expenditures									$ 285,530	$ 476,368	$ 563,724
Gain (loss) on disposal of assets									(1,122)	208	6,092
Other depreciable assets
Property and equipment [Line Items]
Capital expenditures									86,845	125,466	64,889
Construction in progress
Property and equipment [Line Items]
Capital expenditures									$ 202,700	$ 440,900	$ 529,400