Condendsed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 12,799	$ 3,910	$ 23,899	$ 35,028
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	989	(2,017)	1,138	(2,462)
Unrealized (losses) gains on investments, net of tax of $28 and $159 for the second quarter and first six months of 2014, and $3 and $51 for the second quarter and first six months of 2013, respectively	(118)	5	107	87
Total other comprehensive income (loss), net of tax	871	(2,012)	1,245	(2,375)
Comprehensive income	$ 13,670	$ 1,898	$ 25,144	$ 32,653