Basis of Presentation and Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2011	Aug. 31, 2010
Basic and diluted loss per share
Net income (loss)	$ (9,649)	$ (1,397)	$ (192,679)	$ (86,810)
Basic and diluted average shares outstanding	77,047	76,909	77,004	76,866
Basic and diluted loss per share	$ (0.13)	$ (0.02)	$ (2.50)	$ (1.13)