ACQUISITIONS (Details) $ in Thousands, AUD in Millions			1 Months Ended		3 Months Ended								12 Months Ended
	Jan. 29, 2015 USD ($)	Jan. 29, 2015 AUD	Nov. 30, 2015 USD ($)	Nov. 30, 2015 AUD	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2017 USD ($) aircraft	Mar. 31, 2016 USD ($)	Nov. 01, 2015	Mar. 31, 2015 USD ($)	Jan. 29, 2015 USD ($)	Jan. 29, 2015 AUD
Business Acquisition [Line Items]
Payments of contingent consideration													$ 10,000	$ 9,453	$ 0
Current assets																$ 507,871	$ 593,096
Property and equipment, net																2,254,364	2,283,252
Goodwill																19,798	29,990		$ 75,628
Prepaid expenses and other assets																121,652	161,655
Total assets																3,113,847	3,262,945
Current liabilities, including debt																(416,354)	(390,368)
Long-term debt, less current maturities																(1,150,956)	(1,071,578)
Other long-term liabilities																(28,899)	(33,273)
Redeemable noncontrolling interest					$ (6,886)			$ (15,473)	$ (15,473)				(15,473)	(15,473)		$ (6,886)	(15,473)
Revenues					336,194	$ 337,443	$ 357,467	369,398	381,719	$ 419,887	$ 446,911	$ 466,996	1,400,502	1,715,513	1,858,669
Redeemable noncontrolling interest, beginning balance								15,473					15,473
Accretion of redeemable noncontrolling interest													0	1,498	0
Redeemable noncontrolling interest, ending balance					$ 6,886				15,473				6,886	15,473
Airnorth
Business Acquisition [Line Items]
Business acquisition, percentage of voting interests acquired																		15.00%		85.00%	85.00%
Acquisition cost	$ 24,000	AUD 30.3	$ 5,300	AUD 7.3
Potential earn-out payments																				$ 13,000	AUD 17.0
Redeemable non controlling interest, carrying amount, period increase (decrease)			(5,500)
Adjustments to additional paid in capital			$ 2,600
Business combination contingent consideration arrangement terms	4 years	4 years
Payments of contingent consideration														1,500
Number of aircraft owned | aircraft																14
Current assets																				15,188
Property and equipment, net																				39,822
Goodwill																				24,252
Prepaid expenses and other assets																				4,403
Total assets																				83,665
Current liabilities, including debt																				(20,104)
Long-term debt, less current maturities																				(20,606)
Other long-term liabilities																				(9,441)
Total liabilities																				(50,151)
Redeemable noncontrolling interest	$ (3,427)							0	0			(3,339)	0	(3,339)	(3,339)		$ 0		$ (3,339)	(3,427)
Net assets																				$ 30,087
Revenues													77,100	75,400	11,400
Redeemable noncontrolling interest, beginning balance								$ 0				$ 3,339	$ 0	3,339
Noncontrolling interest expense														788	(39)
Accretion of redeemable noncontrolling interest														1,498
Acquisition of noncontrolling interest														(5,467)
Currency translation														(158)	(49)
Redeemable noncontrolling interest, ending balance	$ 3,427								$ 0					$ 0	3,339
Business acquisition, pro forma gross revenue															1,927,680
Business acquisition, pro forma net income															$ 87,902
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