OTHER FINANCIAL INFORMATION (Schedule of Interest Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2017
Condensed Income Statements, Captions [Line Items]
Total interest expense	$ 16,726	$ 10,280	$ 9,896
2020 Convertible Notes [Member]
Condensed Income Statements, Captions [Line Items]
Stated interest	2,308	2,806	2,803
Amortization of note discount	5,769	6,627	6,232
Amortization of debt issue costs	715	845	795
Interest expense on convertible notes	8,792	10,278	9,830
2025 Convertible Notes [Member]
Condensed Income Statements, Captions [Line Items]
Stated interest	2,811
Amortization of note discount	4,637
Amortization of debt issue costs	343
Interest expense on convertible notes	7,791
Other interest expense	143	2	66
Total interest expense	$ 16,726	$ 10,280	$ 9,896