ACQUISITIONS (Details) £ in Millions, AUD in Millions					1 Months Ended		3 Months Ended								12 Months Ended
	Jan. 29, 2015 USD ($)	Jan. 29, 2015 AUD	Feb. 06, 2014 GBP (£)	Feb. 06, 2014 USD ($)	Nov. 30, 2015 USD ($)	Nov. 30, 2015 AUD	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2016 USD ($) aircraft	Nov. 01, 2015	Mar. 31, 2015 USD ($)	Jan. 29, 2015 USD ($)	Jan. 29, 2015 AUD	Mar. 31, 2014 USD ($)	Feb. 06, 2014 USD ($)
Business Acquisition [Line Items]
Payments of contingent consideration															$ 9,453,000	$ 0	$ 6,000,000
Current assets																		$ 593,096,000		$ 637,851,000
Property and equipment, net																		2,283,252,000		2,157,101,000
Goodwill																		29,990,000		75,628,000			$ 56,680,000
Prepaid expenses and other assets																		170,572,000		143,764,000
Total assets																		3,271,862,000		3,230,720,000
Current liabilities, including debt																		(392,690,000)		(435,006,000)
Long-term debt, less current maturities																		(1,078,173,000)		(845,692,000)
Other long-term liabilities																		(33,273,000)		(39,782,000)
Redeemable noncontrolling interests							$ (15,473,000)			$ (26,223,000)	$ (26,223,000)				(26,223,000)	(26,223,000)		$ (15,473,000)		(26,223,000)
Revenues							381,719,000	$ 419,887,000	$ 446,911,000	466,996,000	450,355,000	$ 460,140,000	$ 475,636,000	$ 472,538,000	1,715,513,000	1,858,669,000	1,669,582,000
Redeemable noncontrolling interest, beginning balance										26,223,000					26,223,000
Accretion of redeemable noncontrolling interest															1,498,000	0	0
Redeemable noncontrolling interest, ending balance							15,473,000				26,223,000				15,473,000	26,223,000
Airnorth
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired																			15.00%		85.00%	85.00%
Acquisition cost	$ 24,000,000	AUD 30.3			$ 5,300,000	AUD 7.3
Potential earn-out payments																					$ 13,000,000	AUD 17.0
Redeemable non controlling interest, carrying amount, period increase (decrease)					(5,467,000)
Adjustments to additional paid in capital					$ 2,600,000
Business combination contingent consideration arrangement terms	4 years	4 years
Payments of contingent consideration															1,500,000
Number of aircrafts owned | aircraft																		13
Current assets																					15,188,000
Property and equipment, net																					39,822,000
Goodwill																					24,252,000
Prepaid expenses and other assets																					4,403,000
Total assets																					83,665,000
Current liabilities, including debt																					(20,104,000)
Long-term debt, less current maturities																					(20,606,000)
Other long-term liabilities																					(9,441,000)
Total liabilities																					(50,151,000)
Redeemable noncontrolling interests	$ (3,427,000)						0			(3,339,000)	(3,339,000)				(3,339,000)	(3,339,000)		$ 0		(3,339,000)	(3,427,000)
Net assets																					$ 30,087,000
Revenues															75,400,000	11,400,000
Redeemable noncontrolling interest, beginning balance										3,339,000					3,339,000
Noncontrolling interest expense															788,000	(39,000)
Accretion of redeemable noncontrolling interest															1,498,000
Acquisition of noncontrolling interest															(5,467,000)
Currency translation															(158,000)	(49,000)
Redeemable noncontrolling interest, ending balance	$ 3,427,000						0				3,339,000				0	3,339,000
Business acquisition, pro forma gross revenue															1,927,680,000	1,734,911,000
Business acquisition, pro forma net income															87,902,000	187,785,000
Airnorth | Turboprop
Business Acquisition [Line Items]
Number of aircrafts owned | aircraft																		9
Airnorth | Regional Jets
Business Acquisition [Line Items]
Number of aircrafts owned | aircraft																		4
Airnorth | Call option
Business Acquisition [Line Items]
Option indexed to issuer's equity, period	6 months	6 months
Airnorth | Put option
Business Acquisition [Line Items]
Option indexed to issuer's equity, period	3 years	3 years
Eastern Airways
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired			60.00%																					60.00%
Acquisition cost			£ 27	$ 44,000,000
Potential earn-out payments			£ 6																					$ 9,000,000
Business combination contingent consideration arrangement terms			3 years	3 years
Current assets																								21,117,000
Property and equipment, net																								63,391,000
Goodwill																								26,479,000
Prepaid expenses and other assets																								20,474,000
Total assets																								131,461,000
Current liabilities, including debt																								(37,644,000)
Long-term debt, less current maturities																								(20,400,000)
Other long-term liabilities																								(8,239,000)
Total liabilities																								(66,283,000)
Redeemable noncontrolling interests				$ (21,139,000)			(15,473,000)			(22,885,000)	(22,885,000)			(22,283,000)	(22,885,000)	(22,283,000)	(22,283,000)	$ (15,473,000)		$ (22,885,000)			$ (22,283,000)	(21,139,000)
Net assets																								$ 44,039,000
Revenues															133,500,000	144,800,000	21,200,000
Redeemable noncontrolling interest, beginning balance										$ 22,885,000				$ 22,283,000	22,885,000	22,283,000
Noncontrolling interest expense															(6,499,000)	3,389,000	671,000
Currency translation															(913,000)	(2,787,000)	473,000
Redeemable noncontrolling interest, ending balance				$ 21,139,000			$ 15,473,000				$ 22,885,000				$ 15,473,000	22,885,000	$ 22,283,000
Business acquisition, pro forma gross revenue																1,761,390,000
Business acquisition, pro forma net income																$ 188,921,000
Eastern Airways | Put option
Business Acquisition [Line Items]
Option indexed to issuer's equity, period			7 years	7 years