PENSION BENEFIT PLANS - Schedule of Net Periodic Pension Costs of Noncontributory Defined Benefit Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Retirement Benefits [Abstract]
Service cost	$ 70	$ 81	$ 141	$ 165
Interest cost	136	157	273	321
Net periodic pension cost	$ 206	$ 238	$ 414	$ 486