EMPLOYEE BENEFIT PLANS Components of Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Retirement Benefits [Abstract]
Service cost	$ 856	$ 627	$ 8,243
Interest cost	12,914	15,330	20,108
Expected return on assets	(21,184)	(21,697)	(27,208)
Amortization of unrecognized losses	8,151	7,266	8,246
Net periodic pension cost	$ 737	$ 1,526	$ 9,389