Condendsed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 28, 2013	Feb. 29, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 31,118	$ 7,489
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(445)	3,033
Unrealized gains on investments, net of tax provision of $48 in 2013 and tax benefit of $277 in 2012	82	423
Total other comprehensive (loss) income, net of tax	(363)	3,456
Comprehensive income	$ 30,755	$ 10,945