DEBT (Details)	1 Months Ended	3 Months Ended
	Aug. 13, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Apr. 17, 2015 USD ($)	Mar. 31, 2015 USD ($)
Debt Instrument [Line Items]
Total debt		$ 945,201,000			$ 864,422,000
Short-term borrowings and current maturities of long-term debt		(26,954,000)			(18,730,000)
Total long-term debt		918,247,000			845,692,000
Proceeds from borrowings		364,774,000	$ 148,044,000
Long Term Convertible Debt Current And Noncurrent [Abstract]
Amortization of debt discount		918,000	$ 1,055,000
Term Loan [Member]
Debt Instrument [Line Items]
Total debt		346,084,000		$ 222,600,000	222,179,000
Repayment of debt		3,500,000
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Total debt		$ 1,869,000			114,109,000
Debt Instrument, Interest Rate, Stated Percentage		3.00%
Debt instrument, repurchase amount		$ 113,100,000
Per principal amount of convertible debt		1,000
Balances Of Debt And Equity Components [Abstract]
Equity component- net carrying value		14,905,000			14,905,000
Debt instrument, face amount		1,869,000			115,000,000
Debt component- unamortized discount		0			(891,000)
Debt component - net carrying value		$ 1,869,000			114,109,000
Long Term Convertible Debt Current And Noncurrent [Abstract]
Debt Instrument, Convertible, Effective Interest Rate		6.90%	6.90%
Contractual coupon interest		$ 718,000	$ 863,000
Amortization of debt discount		891,000	1,019,000
Total interest expense		1,609,000	$ 1,882,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt		155,000,000			83,800,000
Repayment of debt		166,200,000
Proceeds from borrowings		237,400,000
Letters of credit outstanding, amount		500,000
Balances Of Debt And Equity Components [Abstract]
Debt instrument, face amount				350,000,000
Senior Notes Due 2022 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt		401,535,000			401,535,000
Debt Instrument, Interest Rate, Stated Percentage			6.25%
Debt instrument, repurchase amount			$ 11,300,000
Airnorth [Member] | Other Debt [Member]
Debt Instrument [Line Items]
Total debt		21,929,000			23,119,000
Eastern Airways [Member] | Other Debt [Member]
Debt Instrument [Line Items]
Total debt		$ 18,784,000			$ 19,680,000
Scenario, Forecast [Member] | Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Repayment of debt	$ 1,900,000
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	100.00%
Base Conversion [Member] | Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio		13.8373
Base Conversion [Member] | Scenario, Forecast [Member] | Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	13.8373
Per principal amount of convertible debt	$ 1,000
Fifth Amendment [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Total debt				350,000,000
Fifth Amendment [Member] | Revolving Credit Facility [Member]
Balances Of Debt And Equity Components [Abstract]
Debt instrument, face amount				$ 400,000,000