Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (6,594)	$ (7,861)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,848	1,218
Stock-based compensation expense	1,913	1,140
Change in fair value of preferred stock warrant		150
Other	248	162
Changes in operating assets and liabilities net of effects of acquisitions:
Accounts receivable	(1,381)	(969)
Prepaid expenses and other current assets	(203)	(545)
Other assets	21	18
Accounts payable	(434)	202
Accrued expenses and other liabilities	1,125	(276)
Deferred revenue	715	97
Deferred rent	44	120
Net cash used in operating activities	(2,698)	(6,544)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of property and equipment	(1,137)	(3,396)
Change in restricted cash and deposits		780
Acquisition of business		(3,000)
Net cash used in investing activities	(1,137)	(5,616)
CASH FLOWS FROM FINANCING ACTIVITIES
Repayment on financing and capital lease obligations	(87)	(10)
Payments of deferred offering cost		(263)
Proceeds from employee stock purchase plan	1,679
Proceeds from exercise of equity awards	302	3
Other	(33)	(73)
Net cash provided by (used in) financing activities	1,861	(343)
Effect of exchange rate changes on cash and cash equivalents	20	(73)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(1,954)	(12,576)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	93,405	34,675
CASH AND CASH EQUIVALENTS, END OF PERIOD	91,451	22,099
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes	31	7
Cash paid for interest	324	12
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Accretion of redeemable convertible preferred stock to redemption value		5,459
Deemed dividend—preferred stock modification		1,748
Unpaid equipment purchases	$ 2,903	2,208
Reclassification of restricted stock award liability to common stock		88
Property and equipment acquired with financing obligations and leases		1,358
Stock issued in business acquisition		1,500
Unpaid offering costs		$ 1,549