Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net loss	$ (25,791)	$ (21,914)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,344	1,787
Stock-based compensation expense	10,918	3,617
Deferred income taxes	(143)
Changes in operating assets and liabilities:
Accounts receivable, net	(2,713)	(2,856)
Prepaid expenses and other current assets	(2,151)	(1,233)
Other assets	(579)	(183)
Accounts payable	478	2,606
Accrued expenses and other current liabilities	(5,823)	3,087
Deferred revenue	11,837	9,932
Deferred rent	(21)	86
Net cash used in operating activities	(9,644)	(5,071)
Cash flows from investing activities:
Purchase of property and equipment	(4,263)	(5,863)
Capitalized software development	(404)	(221)
Net cash used in investing activities	(4,667)	(6,084)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discount		80,506
Proceeds from private placement		6,500
Proceeds from issuance of common stock upon exercise of stock options	3,327	1,416
Proceeds from the issuance of common stock issued under the employee stock purchase plan	3,384
Investment from redeemable non-controlling interests	1,953
Repurchase of unvested common stock from terminated employees	(46)	(16)
Withholding taxes remitted for the net share settlement of equity awards	(1,692)
Proceeds from issuance of debt		3,089
Repayment of debt	(868)	(116)
Payment of deferred initial public offering and follow-on offering costs	(104)	(2,537)
Payment incurred for common stock registration related to acquisition	(319)
Net cash provided by financing activities	5,635	88,842
Effect of foreign exchange rate changes on cash and cash equivalents	91	(52)
Net increase (decrease) in cash and cash equivalents	(8,585)	77,635
Cash and cash equivalents - beginning of period	128,299	44,247
Cash and cash equivalents - end of period	119,714	121,882
Supplemental disclosures of cash flow information:
Cash paid for interest	147	69
Cash paid for income taxes	44	28
Supplemental disclosure of noncash investing and financing activities:
Conversion of convertible preferred stock into common stock		119,121
Vesting of early exercise options	190	410
Property and equipment acquired through tenant improvement allowance		$ 1,136