Condendsed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net income (loss)	$ 3,910	$ (1,908)	$ 35,028	$ 5,581
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(2,017)	(5,056)	(2,462)	(2,023)
Unrealized gains on investments, net of tax of $3 and $51 for the second quarter and the first six months of 2013 and $368 and $91 for the second quarter and first six months of 2012, respectively	5	396	87	819
Total other comprehensive (loss) income, net of tax	(2,012)	(4,660)	(2,375)	(1,204)
Comprehensive income (loss)	$ 1,898	$ (6,568)	$ 32,653	$ 4,377