REVENUE RECOGNITION - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
	Apr. 01, 2018	Sep. 30, 2018	Sep. 30, 2018	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Retained earnings	$ 430,642	$ 341,710	$ 341,710	$ 396,493
Capitalized contract cost	7,100	5,600	5,600
Deferred tax liability	159,462	135,738	135,738	151,563
Deferred revenue	361,855	307,233	307,233
Unrecognized accounts receivable and deferred revenue		10,000	10,000	$ 20,000
Capitalized contract cost, amortization		1,800	3,300
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Revenue will not be recognized in future periods	34,900
Effect of Change Higher (Lower) | Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Retained earnings	34,149	27,464	27,464
Deferred tax liability	$ 7,899	6,254	6,254
Prepaid expenses and other current assets
Disaggregation of Revenue [Line Items]
Capitalized contract cost		3,600	3,600
Other assets
Disaggregation of Revenue [Line Items]
Capitalized contract cost		$ 2,000	$ 2,000
Minimum
Disaggregation of Revenue [Line Items]
Payment terms			30 days
Maximum
Disaggregation of Revenue [Line Items]
Payment terms			90 days