CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Revenue	$ 121,066	$ 97,257	$ 94,739
Cost of revenue	40,405	32,458	34,500
Gross profit	80,661	64,799	60,239
Operating expenses:
Research and development	42,829	37,618	34,449
Selling, general and administrative	17,926	15,926	10,313
Total operating expenses	60,755	53,544	44,762
Income from operations	19,906	11,255	15,477
Other income (loss), net	136	(90)	(47)
Income before income taxes	20,042	11,165	15,430
Provision for income taxes	1,854	1,344	1,501
Net income	$ 18,188	$ 9,821	$ 13,929
Net income per share attributable to ordinary shareholders:
Basic	$ 0.64	$ 0.32	$ 0.54
Diluted	$ 0.60	$ 0.30	$ 0.50
Weighted-average shares used to compute net income per share attributable to ordinary shareholders:
Basic	13,511,646	7,961,944	7,458,627
Diluted	15,016,986	9,469,820	9,107,073