CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Cash flows from operating activities
Net loss	$ (16,134)	$ (20,470)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	1,425	931
Change in fair value of preferred stock warrants	0	14,087
Stock-based compensation expense	9,835	2,672
Excess tax benefit from employee stock plans	(111)	0
Changes in operating assets and liabilities
Accounts receivable, net	26,032	11,015
Prepaid expenses, other current and non-current assets	(298)	12
Accounts payable	918	1,006
Accrued compensation	(6,932)	(4,457)
Accrued expenses and other liabilities	2,491	295
Deferred revenue	2,625	6,477
Net cash provided by operating activities	19,851	11,568
Cash flows from investing activities
Purchases of property and equipment	(1,263)	(1,877)
Net cash used in investing activities	(1,263)	(1,877)
Cash flows from financing activities
Repayments of term debt	0	(2,289)
Proceeds from initial public offering, net of offering costs	0	226,512
Proceeds from exercise of stock options	6,607	546
Excess tax benefit from employee stock plans	111	0
Net cash provided by financing activities	6,718	224,769
Effect of exchange rate changes on cash and cash equivalents	7	18
Net increase in cash and cash equivalents	25,313	234,478
Cash and cash equivalents
Beginning of period	305,939	31,599
End of period	331,252	266,077
Supplemental disclosures
Cash paid for interest	0	40
Cash paid for income taxes	181	0
Non-cash investing and financing activities
Accrued purchases of property and equipment	119	419
Vesting of early exercised options	28	191
Conversion of preferred stock to common stock	0	40,913
Deferred offering costs not yet paid	$ 0	$ 999