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	$ (307,063)	$ (121,949)	$ (63,708)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	110,430	26,095	18,764
Non-cash reduction to the right-of-use asset	23,193	0	0
Net amortization of investment premium and discount	(4,501)	(1,496)	262
Amortization of debt discount and issuance costs	23,696	14,053	0
Stock-based compensation	264,318	93,273	49,619
Tax benefit related to release of valuation allowance	(55,745)	0	0
Other adjustments	7,676	12,824	2,018
Changes in operating assets and liabilities:
Accounts receivable	(51,357)	(58,234)	(15,280)
Prepaid expenses and other current assets	(20,316)	(8,739)	2,214
Other long-term assets	(18,021)	(5,305)	(1,984)
Accounts payable	17,255	6,980	5,433
Accrued expenses and other current liabilities	46,154	45,120	(3,312)
Deferred revenue and customer deposits	2,968	5,958	3,560
Operating right of use liability	(21,138)	0	0
Long-term liabilities	(3,501)	(597)	(841)
Net cash provided by operating activities	14,048	7,983	(3,255)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions, net of cash acquired	122,749	(30,574)	(22,621)
Purchases of marketable securities and other investments	(2,038,422)	(279,687)	(293,186)
Proceeds from sales and maturities of marketable securities	697,171	195,497	115,877
Capitalized software development costs	(21,922)	(19,546)	(17,280)
Purchases of long-lived assets	(45,368)	(5,109)	(9,538)
Net cash used in investing activities	(1,285,792)	(139,419)	(226,748)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from a public offering, net of underwriting discount	980,000	0	0
Payments of costs related to public offerings	(877)	0	(430)
Proceeds from issuance of convertible senior notes	0	550,000	0
Payment of debt issuance costs	0	(12,941)	0
Purchase of capped call	0	(58,465)	0
Principal payments on notes payable	(5,400)	0	0
Principal payments on finance leases	(5,646)	0	0
Proceeds from exercises of stock options and shares issued in ESPP	57,480	39,879	37,645
Value of equity awards withheld for tax liabilities	(5,412)	(2,654)	(678)
Repurchases of common stock	0	0	(100)
Net cash provided by financing activities	1,020,145	515,819	36,437
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0	163	74
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(251,599)	384,546	(193,492)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—Beginning of period	505,334	120,788	314,280
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	253,735	505,334	120,788
Cash paid for income taxes, net	1,368	564	605
Cash paid for interest	2,290	741	0
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Finance lease right-of-use assets assumed in a business combination	14,173	0	0
Purchases of property and equipment through finance leases	5,848	2,478	0
Acquisition holdback	7,980	2,290	0
Value of common stock issued and stock awards assumed in acquisition	2,841,452	0	0
Stock-based compensation capitalized in software development costs	$ 7,777	$ 5,706	$ 4,176