EMPLOYEE BENEFIT PLANS - Components of Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan [Abstract]
Service cost for benefits earned during the period	$ 210	$ 212	$ 429	$ 418
Interest cost on pension benefit obligation	3,221	3,187	6,585	6,300
Expected return on assets	(4,247)	(5,228)	(8,681)	(10,334)
Amortization of unrecognized losses	1,970	2,011	4,027	3,976
Net periodic pension cost	$ 1,154	$ 182	$ 2,360	$ 360