FINANCING ARRANGEMENTS (Long-term Debt) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Feb. 28, 2018 USD ($) $ / shares shares	Feb. 29, 2016 USD ($)	Feb. 28, 2017 USD ($)	May 31, 2015 USD ($)
Debt Instrument [Line Items]
Issuance costs attributable to the liability component		$ 5,291
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 172,500		$ 172,500
Interest rate (as a percent)	1.625%	1.625%	1.625%
Maturity date	May 15, 2020
Conversion rate of shares of common stock	36.2398
Conversion price (in dollars per share) | $ / shares	$ 27.594
Equity component of issuance costs	$ 1,000
Net proceeds from sale of the Notes	167,200
Unamortized issuance costs	5,300
Net proceeds used to pay the cost of the convertible note hedge transactions	$ 15,400
Minimum percentage of aggregate principal by holders	25.00%
Percentage of repurchase price of the principal amount	100.00%
Indebtedness for excess money borrowed	$ 10,000
Indebtedness, entry of judgments for payment	$ 10,000
Debt Instrument, Covenant Description	The Indenture contains customary terms and conditions, including that upon certain events of default occurring and continuing, either the Trustee or the holders of at least 25% in aggregate principal amount of the then outstanding Notes, by notice to us and the Trustee, may declare 100% of the principal amount of, and accrued and unpaid interest, if any, on all the Notes then outstanding to be due and payable immediately. Such events of default include, without limitation, the default by us or any of our subsidiaries with respect to indebtedness for borrowed money in excess of $10 million and the entry of judgments for the payment of $10 million or more against us or any of our subsidiaries which are not paid, discharged or stayed within 60 days.
Maximum number of shares of common stock that could be issued, following certain corporate events that occur prior to maturity | shares	2,500,000
Fair value of the Notes	$ 188,000			$ 138,900
Discount rate (as a percent)	6.20%
Conversion premium	$ 33,600
Debt discount to be amortized	16,143		$ 22,770	$ 33,600
Deferred tax effect of conversion feature	$ 16,000
Effective interest rate	6.20%
Issuance costs attributable to the liability component	$ 4,300
Deferred tax asset related to notes issuance	$ 400
Convertible Senior Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, default judgment payment period	60 days