TAXES Rollforward of deferred tax valuation allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance - beginning balance	$ (74,727)	$ (29,373)	$ (11,700)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Additional Allowances	(20,259)	(45,354)	(17,673)
Valuation Allowance, Deferred Tax Asset, Decrease, Reversals	22,999	0	0
Deferred Tax Assets, Valuation Allowance - ending balance	$ (71,987)	$ (74,727)	$ (29,373)