Marketable Securities and Equity Investments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Summary of cash, cash equivalents and marketable securities
Cash	$ 3,200,000,000		$ 3,300,000,000
Other-than-temporary declines in fair value of available-for-sale debt securities	0	$ 0
Net unrealized losses	(75,600,000)	$ (52,300,000)
Other Assets
Summary of cash, cash equivalents and marketable securities
Equity securities without readily determinable fair value, amount	$ 85,800,000