Comprehensive Income (Loss) (Details) (USD $)	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Cumulative translation adjustment, net of tax	$ (17,436,000)	$ (21,057,000)	$ (22,066,000)
Unrealized gain (loss) on available-for-sale securities	25,000	25,000	(10,000)
Total accumulated other comprehensive loss	(17,411,000)	(21,032,000)	(22,076,000)
Cumulative translation adjustment, tax effects	$ 8,900,000	$ 10,100,000	$ 10,400,000