Condensed Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Stock-based expenses	$ 139,460	$ 141,536	$ 412,963	$ 366,741
Cost of revenues
Amortization of purchased intangibles from business combinations	20,351	33,844	70,294	77,699
Stock-based expenses	14,118	12,119	38,905	32,778
Marketing and sales
Amortization of purchased intangibles from business combinations	15,095	15,211	44,708	22,147
Stock-based expenses	72,892	73,296	210,510	189,231
Research and development
Stock-based expenses	26,868	27,935	87,264	78,396
General and administrative
Stock-based expenses	$ 25,582	$ 28,186	$ 76,284	$ 66,336