Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (94,791)	$ (36,503)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	32,239	21,248
Non-cash reduction to the right-of-use asset	8,023	4,854
Amortization of debt discount and issuance costs	6,178	5,841
Stock-based compensation	69,025	58,324
Tax benefit related to release of valuation allowance	(162)	(51,644)
Allowance for credit losses	4,170	11
Value of donated common stock	2,701	0
Other adjustments	4,352	(444)
Changes in operating assets and liabilities:
Accounts receivable	(23,123)	(206)
Prepaid expenses and other current assets	(8,130)	(9,479)
Other long-term assets	(5,759)	(2,959)
Accounts payable	(20,803)	1,161
Accrued expenses and other current liabilities	44,840	4,348
Deferred revenue and customer deposits	589	377
Operating right of use liability	(7,008)	(1,784)
Long-term liabilities	3,194	(2,258)
Net cash provided by (used in) operating activities	15,535	(9,113)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions, net of cash acquired, and other related payments	(2,377)	156,783
Purchases of marketable securities and other investments	(228,025)	(419,498)
Proceeds from sales and maturities of marketable securities	316,992	140,518
Capitalized software development costs	(8,626)	(5,351)
Purchases of long-lived assets	(6,319)	(2,653)
Net cash provided by (used in) investing activities	71,645	(130,201)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on finance leases and notes payable	(1,954)	(1,455)
Proceeds from exercises of stock options	8,231	15,328
Value of equity awards withheld for tax liabilities	(1,674)	(1,062)
Net cash provided by financing activities	4,603	12,811
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	91,783	(126,503)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—Beginning of period	253,735	505,334
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	345,518	378,831
Cash paid for income taxes, net	257	(34)
Cash paid for interest	198	148
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property, equipment and intangible assets, accrued but not paid	5,510	1,821
Purchases of property and equipment through finance leases	0	13,616
Value of common stock issued and stock awards assumed in acquisition	0	2,850,518
Stock-based compensation capitalized in software development costs	$ 3,418	$ 1,623