CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Feb. 28, 2018	Feb. 28, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	35,718,000	35,330,000
Common stock, shares outstanding	35,718,000	35,330,000
Convertible Senior Notes [Member]
Interest rate (as a percent)	1.625%	1.625%