EARNINGS PER SHARE AND ACCUMULATED OTHER COMPREHENSIVE INCOME - Computation of Basic and Diluted EPS (Details)	3 Months Ended		6 Months Ended
	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares shares
Dividends, Share Repurchases, Earning Per Share and Accumulated Other Comprehensive Income [Abstract]
Loss available to common stockholders – basic | $	$ (144,190,000)	$ (31,209,000)	$ (176,298,000)	$ (86,484,000)
Interest expense on assumed conversion of 4½% Convertible Senior Notes, net of tax (1) | $	0	0	0	0
Loss available to common stockholders – diluted | $	$ (144,190,000)	$ (31,209,000)	$ (176,298,000)	$ (86,484,000)
Weighted average number of common shares outstanding – basic | shares	35,768,232	35,317,935	35,685,388	35,253,688
Assumed conversion of 4½% Convertible Senior Notes outstanding during period (1) | shares	0	0	0	0
Net effect of dilutive stock options and restricted stock awards based on the treasury stock method | shares	0	0	0	0
Weighted average number of common shares outstanding – diluted | shares	35,768,232	35,317,935	35,685,388	35,253,688
Basic loss per common share (in dollars per share) | $ / shares	$ (4.03)	$ (0.88)	$ (4.94)	$ (2.45)
Diluted loss per common share (in dollars per share) | $ / shares	(4.03)	$ (0.88)	(4.94)	$ (2.45)
Convertible Debt | 4½% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Debt Instrument, Convertible, Conversion Price | $ / shares	$ 15.64		$ 15.64
Debt Instrument, Convertible, Conversion Ratio			63.9488
Debt Instrument, Convertible, Conversion Per Principal Amount | $			$ 1,000