CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Income Statement [Abstract]
Revenue	$ 33,941	$ 25,921
Cost of revenue	12,248	7,516
Gross profit	21,693	18,405
Operating expenses:
Research and development	11,317	11,473
Selling, general and administrative	5,157	4,025
Total operating expenses	16,474	15,498
Income from operations	5,219	2,907
Other expense	(5)	(2)
Income before income taxes	5,214	2,905
Provision for income taxes	473	303
Net income	$ 4,741	$ 2,602
Net income per share attributable to ordinary shareholders:
Basic	$ 0.17	$ 0.08
Diluted	$ 0.16	$ 0.07
Weighted-average shares used to compute net income per share attributable to ordinary shareholders:
Basic	27,056,932	7,519,360
Diluted	29,066,062	9,031,710