CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Cash flows from operating activities
Net loss	$ (46,377)	$ (30,519)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	4,500	3,357
Impairment of long-lived assets	2,128	0
Change in fair value of preferred stock warrants	0	14,087
Stock-based compensation expense	36,124	11,223
Excess tax benefit from employee stock plans	(539)	0
Changes in operating assets and liabilities
Accounts receivable, net	9,953	(5,683)
Prepaid expenses, other current and non-current assets	(822)	(1,280)
Accounts payable	267	(268)
Accrued compensation	2,532	9,573
Accrued expenses and other liabilities	5,220	66
Deferred revenue	26,433	21,301
Net cash provided by operating activities	39,419	21,857
Cash flows from investing activities
Acquisition, net of cash acquired	(8,958)	0
Change in restricted cash	0	514
Purchases of property and equipment	(7,265)	(5,720)
Net cash used in investing activities	(16,223)	(5,206)
Cash flows from financing activities
Repayments of term debt	0	(2,289)
Proceeds from initial public offering, net of offering costs	0	225,225
Proceeds from exercise of stock options	18,865	2,123
Excess tax benefit from employee stock plans	539	0
Proceeds from employee stock purchase plan	6,076	0
Taxes paid related to net share settlement of equity awards	(2,752)	0
Net cash provided by financing activities	22,728	225,059
Effect of exchange rate changes on cash and cash equivalents	32	15
Net increase in cash and cash equivalents	45,956	241,725
Cash and cash equivalents
Beginning of period	305,939	31,599
End of period	351,895
Supplemental disclosures
Cash paid for interest	0	40
Cash paid for income taxes	297	80
Non-cash investing and financing activities
Accrued purchases of property and equipment	856	60
Vesting of early exercised options	83	818
Conversion of preferred stock to common stock	$ 0	$ 40,913