Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (13,870)	$ (8,658)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	7,646	5,675
Loss on disposal of assets	15	74
Deferred income taxes	62	(224)
Non-cash interest expense on line of credit and term loan		67
Non-cash investment income	(74)
Provision for doubtful accounts and sales reserve	588	95
Stock-based compensation	4,838	2,127
Increase (decrease) in operating assets and liabilities:
Accounts receivable	(3,591)	(391)
Prepaid expenses	(1,552)	(1,188)
Other assets	(980)	(1,743)
Accounts payable	820	251
Accrued payroll and employee related liabilities	2,263	1,558
Accrued expenses	(54)	305
Deferred revenue	7,801	8,605
Other liabilities	467	(18)
Net cash provided by operating activities	4,379	6,535
Cash flows from investing activities:
Capital expenditures	(1,337)	(739)
Proceeds from sale leaseback transaction	794
Payments for acquisition of business, net of acquired cash	(21,235)
Change in restricted cash	(294)
Purchase of short-term investments	(29,955)
Maturities of short-term investments	6,000
Additions to capitalized software development costs	(4,586)	(4,294)
Net cash used in investing activities	(50,613)	(5,033)
Cash flows from financing activities:
Proceeds from line of credit		9,500
Payments on line of credit		(19,500)
Payment on term loan		(5,000)
Payments of issuance costs relating to the line of credit and term loan		(19)
Principal payments on capital leases		(58)
Proceeds from public offering, net of underwriters discount and commissions	10,444	69,750
Payments of public offering costs	(872)	(1,372)
Payments of debt issuance costs	(40)
Payment of contingent consideration	(3,750)
Payments on notes payable		(2,018)
Proceeds from employee stock purchase plan	1,540
Proceeds from option exercises	2,087	748
Proceeds from exercise of warrants		25
Net cash provided by financing activities	9,409	52,056
Effect of exchange rates on cash and cash equivalents	(312)	160
Net (decrease) increase in cash and cash equivalents	(37,137)	53,718
Cash and cash equivalents—beginning of period	60,765	8,578
Cash and cash equivalents—end of period	23,628	62,296
Supplemental disclosures of cash flow information:
Interest		488
Taxes, net of refunds received	25
Supplemental disclosure of non-cash activities:
Capitalized assets included in accounts payable and accrued expenses	24	132
Deferred offering costs in accounts payable and accrued expenses		885
Debt issuance costs included in accounts payable and accrued expenses	100
Stock-based compensation capitalized for software development	$ 34	$ 38