CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 491,108	$ 443,684
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	408,933	350,681
Stock-based compensation	153,804	146,901
Benefit for deferred income taxes	(30,335)	(22,548)
Amortization of debt discount and issuance costs	49,284	47,057
Other non-cash reconciling items, net	12,015	16,284
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(15,225)	(85,439)
Prepaid expenses and other current assets	(15,099)	(21,380)
Accounts payable and accrued expenses	(16,263)	49,818
Deferred revenue	8,263	14,803
Other current liabilities	(17,958)	(1,638)
Other non-current assets and liabilities	(10,864)	(14,316)
Net cash provided by operating activities	1,017,663	923,907
Cash flows from investing activities:
Cash (paid) received for business acquisitions, net of cash acquired	(15,638)	106
Cash paid for asset acquisition	0	(36,376)
Purchases of property and equipment	(265,131)	(395,793)
Capitalization of internal-use software development costs	(170,404)	(168,634)
Purchases of short- and long-term marketable securities	(611,732)	(1,153,526)
Proceeds from sales of short- and long-term marketable securities	438,370	29,809
Proceeds from maturities of short- and long-term marketable securities	823,255	1,301,354
Other, net	(1,665)	(1,980)
Net cash provided by (used in) investing activities	197,055	(425,040)
Cash flows from financing activities:
Proceeds related to the issuance of common stock under stock plans	46,942	45,812
Employee taxes paid related to net share settlement of stock-based awards	(88,195)	(77,299)
Repurchases of common stock	(251,257)	(121,078)
Other, net	(268)	0
Net cash used in financing activities	(292,778)	(152,565)
Effects of exchange rate changes on cash, cash equivalents and restricted cash	(9,228)	3,535
Net increase in cash, cash equivalents and restricted cash	912,712	349,837
Cash, cash equivalents and restricted cash at beginning of period	353,466	394,146
Cash, cash equivalents and restricted cash at end of period	1,266,178	743,983
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds received of $14,261 and $16,674 for the nine months ended September 30, 2021 and 2020, respectively	82,003	31,634
Cash paid for interest expense	5,031	5,235
Cash paid for operating lease liabilities	167,457	144,322
Non-cash activities:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	173,427	128,177
Purchases of property and equipment and capitalization of internal-use software development costs included in accounts payable and accrued expenses	56,401	48,357
Capitalization of stock-based compensation	28,271	28,487
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	1,264,590	742,521
Restricted cash	1,588	1,462
Cash, cash equivalents and restricted cash	$ 1,266,178	$ 743,983