DEFERRED COMPENSATION (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Cash and cash equivalents	$ 390,661	$ 301,970	$ 235,266	$ 276,850
Other long-term liabilities
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation liability, noncurrent	14,100	13,700
Mutual Funds | Short-term investments
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Investments	$ 13,500	12,400
Bank time deposits | Cash and cash equivalents
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Cash and cash equivalents		$ 800