EMPLOYEE BENEFIT PLANS - Components of Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan [Abstract]
Service cost for benefits earned during the period	$ 219	$ 206
Interest cost on pension benefit obligation	3,364	3,113
Expected return on assets	(4,434)	(5,106)
Amortization of unrecognized losses	2,057	1,965
Net periodic pension cost	$ 1,206	$ 178