CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Stock-based compensation expense			$ 21,792	$ 6,538
Cost of revenues
Stock-based compensation expense	865	267	1,570	375
Research and development
Stock-based compensation expense	3,547	1,267	6,590	2,162
Sales and marketing
Stock-based compensation expense	5,156	1,505	9,478	2,363
General and administrative
Stock-based compensation expense	$ 2,389	$ 827	$ 4,154	$ 1,638