PENSION BENEFIT PLANS - Net Periodic Pension Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Retirement Benefits [Abstract]
Service cost	$ 45	$ 63	$ 86	$ 126
Interest cost	106	123	202	244
Net periodic pension cost	$ 151	$ 186	$ 288	$ 370