Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Cash flows from operating activities
Net income	$ 7,221	$ 4,845
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	930	267
Amortization of premiums on short-term investments	312	89
Stock-based compensation	3,256	735
Bad debt expense	28	91
Changes in operating assets and liabilities:
Accounts receivable	(2,812)	(888)
Income taxes	(2,678)	(393)
Other current and non-current assets	(1,861)	(528)
Accounts payable	912	(1,702)
Accrued expenses and other liabilities	5,318	4,947
Deferred revenue	7,492	5,456
Long-term liabilities	12	104
Net cash provided by operating activities	18,130	13,023
Cash flows from investing activities
Purchases of short-term investments	(135,116)	(1,357)
Maturities and sales of investments	3,867	700
Purchases of property and equipment	(299)	(217)
Payments for capitalized internal-use software	(220)
Proceeds from (issuance of) note receivable-related party		253
Payments for restricted cash and deposits	(3)	(212)
Net cash used in investing activities	(131,771)	(833)
Cash flows from financing activities
Proceeds from early exercise of common stock options		43
Proceeds from exercise of common stock options	685	231
Net proceeds from follow-on offering	34,994
Excess tax benefits from stock-based compensation	4,379
Net cash provided by financing activities	40,058	274
Effect of exchange rate changes on cash and cash equivalents	(36)
Net change in cash and cash equivalents	(73,619)	12,464
Cash and cash equivalents at beginning of period	262,507	31,890
Cash and cash equivalents at end of period	188,888	44,354
Supplemental disclosures of other cash flow information:
Cash paid for income taxes	3,918	2,945
Non-cash investing and financing activities:
Property and equipment included in accounts payable and accrued expenses	69	18
Vesting of early exercised stock options	119	153
Offering costs not yet paid	$ 515