Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Feb. 29, 2012	Nov. 30, 2011
Condensed Consolidated Balance Sheets [Abstract]
Allowance for accounts receivable	$ 2,879	$ 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	62,702,462	61,788,629
Common stock, shares outstanding	62,702,462	61,788,629
Accumulated other comprehensive losses	$ (9,600)	$ (13,056)