BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Balance Sheet) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 534,633	$ 301,589	$ 247,649
Software development costs and licenses	36,912	22,188	33,284
Deferred cost of goods sold	20,957	27,984	117,851
Prepaid expenses and other	162,647	167,074	133,454
Deferred cost of goods sold, net of current portion	489	1,032	26,719
Other assets	80,810	108,317	56,887
Accrued expenses and other current liabilities	853,467	984,426	914,748
Deferred revenue	559,024	547,008	777,152
Non-current deferred revenue	15,407	19,133	355,589
Other long-term liabilities	205,554	192,621	158,285
Retained earnings	640,849	543,789	73,516
Accumulated other comprehensive loss	$ (37,199)	$ (11,079)	(15,732)
Previously Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net			247,649
Software development costs and licenses			33,284
Deferred cost of goods sold			117,851
Prepaid expenses and other			133,454
Deferred cost of goods sold, net of current portion			26,719
Other assets			56,887
Accrued expenses and other current liabilities			914,748
Deferred revenue			777,152
Non-current deferred revenue			355,589
Other long-term liabilities			158,285
Retained earnings			73,516
Accumulated other comprehensive loss			(15,732)
Accounting Standards Update 2014-09 | Restatement Adjustment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net			53,940
Software development costs and licenses			(11,096)
Deferred cost of goods sold			(89,867)
Prepaid expenses and other			33,620
Deferred cost of goods sold, net of current portion			(25,687)
Other assets			51,430
Accrued expenses and other current liabilities			69,678
Deferred revenue			(230,144)
Non-current deferred revenue			(336,456)
Other long-term liabilities			34,336
Retained earnings			470,273
Accumulated other comprehensive loss			$ 4,653