Condendsed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 24,843	$ 5,838	$ 59,871	$ 11,419
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(1,548)	658	(4,010)	(1,365)
Unrealized gain (loss) on investments, net of tax provision of $6 and $57 for the third quarter and the first nine months of 2013 and net of tax benefit of $54 and tax provision of $37 for the third quarter and first nine months of 2012, respectively	11	(93)	98	726
Total other comprehensive (loss) income, net of tax	(1,537)	565	(3,912)	(639)
Comprehensive income	$ 23,306	$ 6,403	$ 55,959	$ 10,780