Noncontrolling Interest (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 28, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Total assets	$ 1,946,908				$ 1,332,938				$ 1,946,908	$ 1,332,938
Total revenues	296,527	255,021	247,363	225,702	289,511	228,973	216,421	185,341	1,024,613	920,246	754,007
TS Innovations Limited
Total assets	6,100				5,000				6,100	5,000
Total revenues									$ 10,500	$ 13,100	$ 13,200
Percentage of ownership interest owned by the entity	74.90%								74.90%
Percentage of equity interest owned by noncontrolling shareholders	25.10%								25.10%