Noncontrolling Interest (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2010	May 31, 2010	Feb. 28, 2010	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2009
Total assets	$ 1,332,938				$ 1,204,999				$ 1,332,938	$ 1,204,999
Total revenues	289,511	228,973	216,421	185,341	241,217	184,476	173,270	155,044	920,246	754,007	621,388
Percentage of ownership interest owned by the entity	74.90%								74.90%
Percentage of equity interest owned by noncontrolling shareholders	25.10%								25.10%
TS Innovations Limited [Member]
Total assets	5,000				5,700				5,000	5,700
Total revenues									$ 13,100	$ 13,200	$ 7,500
Percentage of ownership interest owned by the entity	74.90%								74.90%
Percentage of equity interest owned by noncontrolling shareholders	25.10%								25.10%