DEBT - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 1,215,266	$ 1,293,364
Unamortized debt issuance cost	(19,365)	(11,345)
Total debt, net	1,195,901	1,282,019
Less short-term borrowings and current maturities of long-term debt	(93,136)	(131,063)
Total long-term debt	1,102,765	1,150,956
Senior Notes | 6¼% Senior Notes due 2022
Debt Instrument [Line Items]
Total debt	$ 401,535	401,535
Stated interest rate	6.25%
Convertible Debt | 4½% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Total debt	$ 106,124	0
Stated interest rate	4.50%
Term Loan
Debt Instrument [Line Items]
Total debt	$ 52,546	261,907
Term Loan Credit Facility
Debt Instrument [Line Items]
Total debt	0	45,900
Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	0	139,100
Secured Debt | Lombard Debt
Debt Instrument [Line Items]
Total debt	206,831	196,832
Secured Debt | Macquarie Debt
Debt Instrument [Line Items]
Total debt	188,528	200,000
Secured Debt | PK Air Debt
Debt Instrument [Line Items]
Total debt	230,000	0
Other Debt | Airnorth Debt
Debt Instrument [Line Items]
Total debt	14,507	16,471
Other Debt | Eastern Airways Debt
Debt Instrument [Line Items]
Total debt	12,772	15,326
Other Debt | Other Debt
Debt Instrument [Line Items]
Total debt	$ 2,423	$ 16,293