Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Nov. 30, 2011 days years	Nov. 30, 2010	Nov. 30, 2009
Significant Accounting Policies [Line Items]
Percentage of interest in joint venture	74.90%
Noncontrolling Interest, ownership Percentage by noncontrolling owners	25.10%
Reimbursable expenses	$ 11,600,000	$ 10,800,000	$ 8,100,000
Customer balance in excess of 10% of total revenues	0	0	0
Customer balance in excess of 10% of net accounts receivable	0	0
Depreciation of property and equipment	13,145,000	13,414,000	15,107,000
Impairment of goodwill	0
Impairment of IPR&D	0
Purchase price allocation period, maximum, (in years)	1
Number of days after acquisition in which severance related costs are recorded as acquisition expenses	90
Fair value of deferred revenue adjustments, minimum	5,000,000
Gains (Losses) from foreign currency exchange	(1,900,000)	(1,900,000)	1,700,000
Maturities of foreign currency forward contracts, in days	30
Advertising costs	$ 2,400,000	$ 2,500,000	$ 2,700,000
Performance-Based Restricted Stock Units [Member]
Significant Accounting Policies [Line Items]
Percentage of forfeiture upon triggering non-GAAP EPS threshold	20.00%
Fall of non-GAAP EPS in percentage to Trigger forfeiture	10.00%
Foreign Currency Forward Contract Number One [Member]
Significant Accounting Policies [Line Items]
Forward contracts outstanding	4
Foreign Currency Forward Contract Number Two [Member]
Significant Accounting Policies [Line Items]
Forward contracts outstanding	5