INTANGIBLE ASSETS AND GOODWILL - Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Mar. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 45,731	$ 37,277
Accumulated Amortization	(17,321)	(25,597)
Net Carrying Amount	28,410	11,680
Full amortized intangible assets written off	11,300
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	33,466	25,702
Accumulated Amortization	(12,706)	(15,409)
Net Carrying Amount	20,760	10,293
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,293	9,467
Accumulated Amortization	(4,534)	(8,080)
Net Carrying Amount	6,759	1,387
Trade and domain names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	972	2,108
Accumulated Amortization	(81)	(2,108)
Net Carrying Amount	$ 891	$ 0