Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income		$ 2,711,647	$ 1,176,810	$ 2,087,103
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense		429,461	360,489	325,047
Depreciation expense		109,515	106,941	72,420
Deferred income taxes (including benefit from valuation allowance release in 2018)		277,341	167,387	(1,512,325)
Gains on equity securities		(311,937)	(197,597)	(2,558)
Increase in fair value of contingent consideration		13,100	4,459	0
Intangible asset impairment charge		0	0	29,000
Other non-cash items, net		78,832	16,942	33,579
Changes in operating assets and liabilities:
Accounts receivable, net		(223,444)	(225,587)	(108,152)
Inventories		(132,014)	(64,047)	(31,965)
Prepaid expenses and other assets		(297,562)	35,440	16,684
Accounts payable		51,276	(22,785)	36,554
Accrued expenses		122,198	172,881	302,755
Other liabilities		425,092	37,997	22,144
Net cash provided by operating activities		3,253,505	1,569,330	1,270,286
Cash flows from investing activities:
Payments to acquire businesses, net of cash acquired		0	(1,154,212)	0
Purchases of available-for-sale debt securities		(431,396)	(537,196)	(431,918)
Maturities of available-for-sale debt securities		372,342	475,924	431,576
Sale of equity securities		437,567	94,936	0
Purchases of property and equipment		(259,798)	(75,451)	(95,449)
Investment in equity securities		(19,327)	(39,319)	(83,471)
Investment in note receivable		0	0	(15,000)
Decrease in restricted cash due to deconsolidation of VIE				(7,896)
Net cash provided by (used in) investing activities		99,388	(1,235,318)	(202,158)
Cash flows from financing activities:
Issuances of common stock under benefit plans		264,946	343,244	289,293
Repurchases of common stock		(539,136)	(186,020)	(350,043)
Payments in connection with common stock withheld for employee tax obligations		(200,271)	(5,995)	0
Payments on finance leases	[1]	(42,275)	(39,185)	(33,388)
Proceeds from finance leases	[1]	13,251	10,046	20,840
Other financing activities		(1,796)	4,683	2,079
Net cash (used in) provided by financing activities		(505,281)	126,773	(71,219)
Effect of changes in exchange rates on cash		20,552	1,643	(6,182)
Net increase in cash, cash equivalents and restricted cash		2,868,164	462,428	990,727
Cash, cash equivalents and restricted cash—beginning of period		3,120,681	2,658,253	1,667,526
Cash, cash equivalents and restricted cash—end of period		5,988,845	3,120,681	2,658,253
Supplemental disclosure of cash flow information:
Cash paid for interest		54,520	55,554	66,458
Cash paid for income taxes		191,776	24,730	12,402
Capitalization of costs related to construction financing lease obligation	[1]	0	0	3,389
Issuances of common stock from employee benefit plans receivable		$ 642	$ 2,820	$ 86

[1] * For the year ended December 31, 2018, amounts are related to the Company’s capital leases and construction financing lease obligations pursuant to ASC 840, Leases, which was applicable until December 31, 2018.