SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of finite-lived intangible asset useful lives (Details)	12 Months Ended
	Mar. 31, 2020
Software
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	3 years
Trade names
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	5 years
Certification
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	5 years
Non-compete
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	5 years
License
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	5 years
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	9 years
Customer relationship
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life (year)	10 years