Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014
Numerator:
Net (loss) income	$ 13,355	$ 21,469	$ 28,308	$ 41,364
Denominator:
Weighted average shares outstanding	46,603,052	46,535,179	46,593,547	46,525,303
Effect of dilutive securities	15,281	13,664	14,122	14,243
Diluted weighted average shares outstanding	46,618,333	46,548,843	46,607,669	46,539,546
Basic and diluted earnings per share
Basic and diluted (loss) earnings per share (in dollars per share)	$ 0.29	$ 0.46	$ 0.61	$ 0.89
Anti-dilutive shares excluded in the computation of diluted earnings per share	104,150	126,116	104,525	131,251