CONVERTIBLE SENIOR UNSECURED NOTES (Long-term Debt) (Details) - Convertible Senior Notes [Member] $ / shares in Units, $ in Thousands, shares in Millions	6 Months Ended
	Aug. 31, 2017 USD ($) $ / shares shares	Feb. 28, 2017 USD ($)	Aug. 31, 2016	May 31, 2015 USD ($)
Debt Instrument [Line Items]
Debt instrument, face amount	$ 172,500	$ 172,500
Interest rate (as a percent)	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
Percentage of repurchase price of the principal amount	100.00%
Maximum number of shares of common stock that could be issued, following certain corporate events that occur prior to maturity | shares	2.5
Debt discount to be amortized	$ 19,507	$ 22,770		$ 33,600
Effective interest rate	6.20%
Equity component of issuance costs	$ 1
Fair value of the Notes	$ 169,500			$ 138,900