Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (26,065)	$ (10,260)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	8,057	7,004
Depreciation of tangible assets	1,056	1,184
Amortization of contract acquisition costs	2,017	2,169
Impairment of capitalized cloud computing costs	805
Change in deferred tax asset	(77)	(2)
Provision for credit losses	1,750	647
Change in right-of-use asset	250
Other	327	55
Changes in assets and liabilities:
Accounts receivable	2,209	(4,232)
Inventories	4,588	(6,028)
Other current assets and prepaid expenses	(1,273)	(1,423)
Other long-term assets	(1,701)	(2,608)
Accounts payable	(5,886)	2,861
Accrued liabilities	(4,559)	4,900
Extended warranty liabilities	(502)	(927)
Other long-term liabilities		(140)
Deferred revenue	(2,398)	907
Income tax liabilities		(301)
Net cash used in operating activities	(21,402)	(6,194)
Cash flows from investing activities:
Acquisition of property and equipment	(774)	(524)
Disposal of property and equipment		45
Proceeds from maturities of marketable investments	19,000	11,450
Purchase of marketable investments	(24,411)	(8,304)
Net cash provided by (used in) investing activities	(6,185)	2,667
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan	856	1,600
Proceeds from long-term debt	7,167
Gross proceeds from equity offering	28,798
Offering costs on the equity offering	(2,303)
Taxes paid related to net share settlement of equity awards	(3,340)	(750)
Payments on finance lease obligations	(513)	(496)
Net cash provided by financing activities	30,665	354
Net increase (decrease) in cash and cash equivalents	3,078	(3,173)
Cash and cash equivalents at beginning of period	26,316	26,052
Cash and cash equivalents at end of period	29,394	22,879
Supplemental disclosure of non-cash items:
Assets acquired under finance lease	27	903
Assets acquired under operating lease	$ 10,623	$ 11,734