Accounts Receivable and Allowances for Doubtful Accounts, Returns and Discounts (Schedule Of Accounts Receivable) (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009
Accounts Receivable And Allowances For Doubtful Accounts, Returns And Discounts [Abstract]
Accounts receivable	$ 220,286	$ 182,788
Unbilled fees for professional services	19,420	19,499
Gross accounts receivable	239,706	202,287
Less: Allowances for doubtful accounts, returns and discounts	(5,606)	(5,868)	(5,729)	(4,224)
Net accounts receivable	$ 234,100	$ 196,419