SOFTWARE DEVELOPMENT COSTS AND LICENSES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Apr. 01, 2018	Mar. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Software development costs and licenses, Current	$ 36,912		$ 36,912		$ 22,188	$ 33,284
Software development costs and licenses, Non-current	794,120		794,120			639,369
Software development impairment charges	0	$ 276	0	$ 960
Software development costs, internally developed
Finite-Lived Intangible Assets [Line Items]
Software development costs and licenses, Current	27,123		27,123			19,338
Software development costs and licenses, Non-current	631,357		631,357			515,761
Software development costs, externally developed
Finite-Lived Intangible Assets [Line Items]
Software development costs and licenses, Current	2,416		2,416			4,275
Software development costs and licenses, Non-current	162,178		162,178			122,270
Licenses
Finite-Lived Intangible Assets [Line Items]
Software development costs and licenses, Current	7,373		7,373			9,671
Software development costs and licenses, Non-current	$ 585		$ 585			$ 1,338