FINANCING ARRANGEMENTS (Schedule of Balances Attributable to Notes) (Details) - USD ($) $ in Thousands	Feb. 28, 2018	Feb. 28, 2017	May 31, 2015
Liability component:
Net carrying amount of the Notes	$ 154,299	$ 146,827
Convertible Senior Notes [Member]
Liability component:
Principal	172,500	172,500
Less: Unamortized debt discount	(16,143)	(22,770)	$ (33,600)
Unamortized debt issuance costs	(2,058)	(2,903)
Net carrying amount of the Notes	$ 154,299	$ 146,827