PENSION BENEFIT PLANS - Defined Benefit Pension Plan (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, at beginning of year	$ 33,464	$ 30,141
Service cost	304	407	$ 329
Interest cost	704	718	638
Benefits paid and other	(302)	(288)
Actuarial loss (gain)	3,254	(1,788)
Foreign exchange rate impact	(2,529)	4,274
Benefit obligation, at end of year	34,895	33,464	30,141
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, at beginning of year	0	0
Employer direct benefit payments	302	288
Benefits paid and other	(302)	(288)
Fair value of plan assets, at end of year	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	304	407	329
Interest cost	704	718	638
Net periodic pension cost	$ 1,008	$ 1,125	$ 967
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	1.80%	2.30%	2.10%
Rate of compensation increase	3.00%	2.25%	2.25%

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

Name:	us-gaap_DefinedBenefitPlanActuarialGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.