EMPLOYEE BENEFIT PLANS (Details) - USD ($)		3 Months Ended		6 Months Ended
	May 23, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Incentive Compensation [Line Items]
Service cost for benefits earned during the period		$ 1,794,000	$ 2,399,000	$ 3,754,000	$ 4,772,000
Interest cost on pension benefit obligation		4,377,000	5,226,000	9,158,000	10,396,000
Expected return on assets		(5,920,000)	(7,014,000)	(12,391,000)	(13,955,000)
Amortization of unrecognized losses		1,793,000	2,153,000	3,755,000	4,285,000
Net periodic pension cost		$ 2,044,000	2,764,000	4,276,000	5,498,000
Cash contributions				12,900,000
Estimated cash contributions				$ 17,800,000
Common Stock shares reserved		10,646,729		10,646,729
Common Stock, par value		$ 0.01		$ 0.01		$ 0.01
Shares available for grant		4,231,748		4,231,748
Additional capital shares reserve	5,246,729
Additional capital full value shares reserve	2,623,365
Shares available for issuance	6,400,000
Full value shares available for issuance	3,200,000
Number of shares settled	2
Number of shares right granted	1
Share based compensation award maximum	1,000,000					500,000
Total compensation authorized for non-employee directors	$ 1,125,000
Stock based compensation expense		$ 2,000,000	6,400,000	$ 6,244,000	10,380,000
Restricted stock grants- shares				642,753
Restricted stock grants- fair value				$ 10.21
Stock option grants- shares				1,024,168
Risk free interest rate				1.07%
Expected life (years)				5 years
Volatility				46.75%
Dividend yield				2.74%
Weighted average exercise price of options granted				$ 16.21
Weighted average grant-date fair value of options granted				$ 2.16
Performance cash compensation liability		9,600,000		$ 9,600,000		$ 15,800,000
Performance cash compensation expense		$ 3,600,000	$ (1,600,000)	$ 2,500,000	$ 1,700,000