DEBT (Details) (USD $)	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014
Debt Instrument [Line Items]
Total debt	$ 955,108,000		$ 841,302,000
Less short-term borrowings and current maturities of long-term debt	(13,851,000)		(14,207,000)
Long-term debt, less current maturities	941,257,000		827,095,000
Debt Instrument, Repurchase Amount	11,300,000
Write-off of deferred debt financing fees	164,000	12,733,000
Proceeds from borrowings	148,044,000	103,357,000
Letters of Credit Outstanding, Amount	500,000
Long Term Convertible Debt Current And Noncurrent [Abstract]
Amortization of debt discount	1,055,000	921,000
Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Total debt	438,745,000		450,000,000
Debt Instrument, Repurchase Amount	11,300,000
Repurchase premium rate	107.75%
Total consideration paid	12,200,000
Other income (expense)	900,000
Write-off of deferred debt financing fees	200,000
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Term Loan [Member]
Debt Instrument [Line Items]
Total debt	225,505,000		226,604,000
Repayment of debt	1,100,000
Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Total debt	110,923,000		109,904,000
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Balances Of Debt And Equity Components [Abstract]
Equity component- net carrying value	14,905,000		14,905,000
Debt Instrument, Face Amount	115,000,000		115,000,000
Debt component- unamortized discount	(4,077,000)		(5,096,000)
Long Term Convertible Debt Current And Noncurrent [Abstract]
Debt Instrument, Convertible, Effective Interest Rate	6.90%	6.90%
Contractual coupon interest	863,000	863,000
Amortization of debt discount	1,019,000	921,000
Total interest expense	1,882,000	1,784,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	152,000,000		24,000,000
Repayment of debt	19,500,000
Proceeds from borrowings	147,500,000
Eastern Airways [Member]
Debt Instrument [Line Items]
Total debt	27,271,000		29,911,000
Other debt [Member]
Debt Instrument [Line Items]
Total debt	$ 664,000		$ 883,000