Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Nov. 30, 2012	Nov. 30, 2011
Statement of Financial Position [Abstract]
Allowances on accounts receivable (in dollars)	$ 3,024	$ 6,683
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	59,594,961	61,788,629
Common stock, shares outstanding	59,594,961	61,788,629