Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Aug. 31, 2012	Nov. 30, 2011
Statement of Financial Position [Abstract]
Allowance for accounts receivable	$ 3,375	$ 6,683
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	63,595,485	61,788,629
Common stock, shares outstanding	63,595,485	61,788,629
Accumulated other comprehensive losses	$ (12,292)	$ (11,653)