SEGMENT INFORMATION - NARRATIVE (Details)	12 Months Ended
	Mar. 31, 2018 segment customer system
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Number of reportable segments | segment	4
Phase I
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Number of Systems Installed	3,724
Phase II
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Number of Systems Installed	8,904
Customer Concentration Risk | Sales Revenue, Net
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Concentration risk, number of customers | customer	1