Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (59,937)	$ (8,857)	$ (63,509)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	15,669	8,389	5,336
Stock-based compensation expense	85,175	37,674	10,953
Provision for doubtful accounts	704	876	104
Change in fair value of preferred stock warrant liability			40,333
Noncash interest expense	531	342	784
(Gain) Loss from exit of facilities and disposal of property and equipment	(2)	1,128	579
Loss from extinguishment of debt			2,338
Impairment of long-lived assets	854	352
Amortization of premiums on short-term investments	(282)	(357)
Changes in operating assets and liabilities:
Accounts receivable	(110,225)	(50,673)	(41,184)
Inventories	(14,129)	(2,953)	10,828
Prepaid expenses and other current assets	(11,566)	(306)	(6,514)
Operating lease right-of-use assets	22,328
Deferred cost of revenue	1,143	2,261	(1,959)
Other noncurrent assets	(3,060)	(732)	(2,794)
Accounts payable	9,409	(98)	24,315
Accrued liabilities	79,058	17,914	24,127
Operating lease liabilities	11,658
Other long-term liabilities	(3,024)	(1,101)	3,579
Deferred revenue	(10,597)	10,063	29,976
Net cash provided by operating activities	13,707	13,922	37,292
Cash flows from investing activities:
Purchase of property and equipment	(77,180)	(18,327)	(9,229)
Purchase of business, net of cash acquired	(68,132)		(2,959)
Purchase of intangible assets	(7,428)
Purchases of short-term investments	(12,365)	(53,806)
Sales/maturities of short-term investments	54,810	12,000
Change in deposits			(80)
Net cash used in investing activities	(110,295)	(60,133)	(12,268)
Cash flows from financing activities:
Proceeds from borrowings, net of issuance costs	99,608		24,691
Repayments of borrowings			(40,446)
Holdback payment for a prior business acquisition		(500)
Proceeds from equity issued under incentive plans, net of repurchases	28,181	25,025	1,773
Net cash provided by financing activities	458,328	24,525	117,664
Net Increase (Decrease) in cash, cash equivalents and restricted cash	361,740	(21,686)	142,688
Effect of exchange rate changes on cash, cash equivalents and restricted cash	29
Cash, cash equivalents and restricted cash —Beginning of period	155,564	177,250	34,562
Cash, cash equivalents and restricted cash —End of period	517,333	155,564	177,250
Cash, cash equivalents and restricted cash at end of period:
Cash and cash equivalents	515,479	155,564	177,250
Restricted cash	1,854
Cash, cash equivalents and restricted cash —End of period	517,333	155,564	177,250
Supplemental disclosures of cash flow information:
Cash paid for interest	3,095	493	1,149
Cash paid for income taxes	759	564	222
Supplemental disclosures of noncash investing and financing activities:
Issuance of common stock for business combinations	69,684
Unpaid portion of property and equipment purchases	10,762	$ 1,617	1,250
Unpaid portion of acquisition related expenses	2,190
Unpaid portion of purchased intangibles	400
Unpaid portion of at-the-market offering costs	144
Fair value of preferred stock warrants reclassified to additional paid in capital			52,355
Issuance of convertible preferred stock warrants in connection with debt			2,032
At-the-Market Offerings
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	$ 330,539
Initial Public Offering
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs			$ 131,646