Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (57,118)	$ (41,712)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	9,390	8,129
Goodwill impairment	9,174
Stock-based compensation	11,411	8,996
Deferred tax expense	(1,110)	(726)
Amortization of deferred rent	231	(659)
Non-cash change in earnout liability	(430)	(996)
Non-cash bad debt (recovery) expense	(382)	221
Other	526	199
Changes in operating assets and liabilities:
Trade accounts receivable	(7,852)	4,294
Prepaid expenses and other current assets	(2,688)	(1,732)
Other long-term assets	(549)	556
Trade payables	(3,353)	805
Accrued expenses and other current liabilities	6,095	1,201
Deferred rent (lease incentives)	579	7,701
Deferred revenue	25,978	12,158
Net cash used in operating activities	(10,098)	(1,565)
Cash flows from investing activities:
Net (increase) decrease in customer fund assets	2,053	(2,050)
Cash paid for acquired intangible assets	(5,002)
Purchase of property and equipment	(12,914)	(10,350)
Net cash used in investing activities	(15,863)	(12,400)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts	192,510
Payments on credit facility	(63,000)	(1,562)
Proceeds from credit facility	23,000	8,000
Payments on capital leases		(14)
Repurchase of shares	(1,806)
Repayment of note payable	(234)
Payments of deferred financing costs	(2,084)	(565)
Taxes paid related to net share settlement of stock-based awards	(2,326)	(268)
Net increase (decrease) in customer fund obligations	(2,053)	2,050
Payment related to business combination earnouts		(83)
Proceeds from exercise of stock options and common stock warrants	5,787	545
Net cash provided by financing activities	149,794	8,103
Foreign currency effect on cash and cash equivalents	185	(19)
Net change in cash and cash equivalents	124,018	(5,881)
Cash and cash equivalents—Beginning of year	14,075	20,230
Cash and cash equivalents—End of year	138,093	14,349
Supplemental cash flow disclosures:
Cash paid for interest expense	2,367	1,532
Cash paid for income taxes	314	238
Non-cash investing and financing activities:
Property and equipment purchased under tenant improvement allowance	1,062	7,839
Property and equipment additions in accounts payable and accrued expenses	607	318
Deferred financing costs, accrued not yet paid	298	870
Fair value of common stock to be issued to purchase intangible assets	2,555
Cashless exercises of options and warrants	9,214	1,275
Cashless redemptions of options and warrants	$ 11,541	$ 1,543