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	$ 1,571,990	$ 2,107,457
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	322,792	332,434
Depreciation expense	91,768	80,160
(Decrease) increase in fair value of contingent consideration	(1,100)	12,600
Deferred income taxes	(112,654)	65,110
Gains on equity securities	(4,993)	(140,866)
Other non-cash items, net	20,588	52,371
Changes in operating assets and liabilities:
Accounts receivable, net	(231,166)	(151,191)
Inventories	(65,827)	(94,907)
Prepaid expenses and other assets	(107,672)	(264,909)
Accounts payable	(22,043)	16,153
Accrued expenses	254,157	451,084
Other liabilities	(67,333)	296,477
Net cash provided by operating activities	1,648,507	2,761,973
Cash flows from investing activities:
Purchases of available-for-sale debt securities	(447,759)	(246,937)
Maturities of available-for-sale debt securities	452,133	184,419
Purchases of property and equipment	(173,285)	(212,109)
Investment in equity securities and notes receivable	(37,991)	(19,327)
Sale of equity securities	0	149,595
Net cash used in investing activities	(206,902)	(144,359)
Cash flows from financing activities:
Issuances of common stock under benefit plans	67,289	234,854
Repurchases of common stock	(1,057,225)	(408,033)
Payments in connection with common stock withheld for employee tax obligations	(134,223)	(179,775)
Payments on finance leases	(34,592)	(31,378)
Proceeds from finance leases	12,647	8,642
Other financing activities	4,339	(4,399)
Net cash used in financing activities	(1,141,765)	(380,089)
Effect of changes in exchange rates on cash	(8,472)	2,779
Net increase in cash, cash equivalents and restricted cash	291,368	2,240,304
Cash, cash equivalents and restricted cash—beginning of period	5,988,845	3,120,681
Cash, cash equivalents and restricted cash—end of period	6,280,213	5,360,985
Supplemental disclosure of cash flow information:
Cash paid for interest	42,698	40,769
Cash paid for income taxes	$ 381,533	$ 81,684