FINANCING ARRANGEMENTS AND CONTRACTUAL CASH OBLIGATIONS (Note Hedge and Warrant Arrangements) (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Apr. 30, 2015	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2015	May 31, 2015
Debt Instrument [Line Items]
Purchase of note hedges, net of tax			$ (19,324)
Proceeds from issuance of warrants			15,991
Warrant [Member]
Debt Instrument [Line Items]
Strike price of underlie convertible notes (in dollars per share)	$ 39.42
Percentage of premium on sale price of common stock	100.00%
Share price (in dollars per share)	$ 19.71
Note Hedge [Member]
Debt Instrument [Line Items]
Number of common stock with hedge transactions		6,250,000
Debt Instrument, Face Amount		$ 172,500
Payments for notes hedges		31,300
Purchase of note hedges, net of tax		$ 19,300
Conversion price for the Notes		$ 27.594
Proceeds from issuance of warrants		$ 16,000
Issue discount interest deductible for income tax purposes		31,300
Deferred tax asset		12,000
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 172,500	$ 172,500		$ 172,500
Conversion price for the Notes		$ 27.594