Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Cash flows from operating activities:
Net income	$ 2,564	$ 1,783
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property and equipment	412	453
Amortization of intangible assets	292	11
Amortization/accretion of marketable securities	57	76
Stock-based compensation	12,972	11,301
Other non-cash items, net	38	30
Changes in operating assets and liabilities:
Accounts receivable	15,725	8,907
Inventories	1,079	246
Prepaid expenses and other current assets	1,093	323
Deferred tax assets	(254)	256
Other assets	56	32
Accounts payable	(2,084)	2,172
Accrued liabilities	(7,055)	(5,210)
Income taxes payable	(13)	(787)
Deferred tax liabilities	0	(58)
Deferred revenue	(1,870)	(3,985)
Other long-term liabilities	11	0
Net cash provided by operating activities	23,023	15,550
Cash flows from investing activities:
Purchase of investments	(7,070)	(35,857)
Sales of investments	1,000	8,974
Maturities of investments	3,490	10,790
Purchase of property and equipment	(955)	(469)
Net cash used in investing activities	(3,535)	(16,562)
Cash flows from financing activities:
Stock repurchase	(8,773)	0
Proceeds from exercise of stock options and employee stock purchase plan	1,595	915
Net cash provided by (used in) financing activities	(7,178)	915
Net increase (decrease) in cash and cash equivalents	12,310	(97)
Cash and cash equivalents at beginning of period	322,872	268,056
Cash and cash equivalents at end of period	335,182	267,959
Supplemental disclosure of cash flow information:
Cash paid for income taxes	290	241
Supplemental disclosure of noncash investing and financing activities:
Increase in liabilities related to intangible and fixed asset purchases	$ 9,937	$ 153