Calculation of Basic and Diluted Net Income Per Share from Continuing Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 28, 2014	Feb. 28, 2013	Feb. 29, 2012
Basic net income (loss):
Net income (loss) available to common shareholders from continuing operations					$ 43,806	$ (8,114)	$ 84,443
Impact of conversion of preferred stock into common stock					(325)	0	(53,301)
Diluted net income (loss):
Net income (loss) available to common shareholders from continuing operations					$ 43,481	$ (8,114)	$ 31,142
Basic shares:
Basic weighted average common shares outstanding (in shares)					40,506	39,034	38,293
Impact of equity awards (in shares)					3,264	0	967
Impact of conversion of preferred stock into common stock (in shares)					2,272	0	5,693
Diluted shares:
Diluted weighted average common shares outstanding (in shares)					46,042	39,034	44,953
Basic net income (loss) per common share:
Basic net income (loss) per common share (in dollars per share)	$ (0.14)	$ 0.02	$ (0.02)	$ (0.07)	$ 1.08	$ (0.21)	$ 2.21
Diluted net income (loss) per common share:
Diluted net income (loss) per common share (in dollars per share)	$ (0.14)	$ 0.02	$ (0.02)	$ (0.07)	$ 0.94	$ (0.21)	$ 0.69