Investments - BeiGene, Ltd. (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 5,482,000,000		$ 4,188,000,000
Net unrealized gains (loss)	0	$ 0
BeiGene
Debt Securities, Available-for-sale [Line Items]
Net unrealized gains (loss)	1,700,000,000	$ (454,000,000)
Other Noncurrent Assets
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 291,000,000		314,000,000
BeiGene | Maximum
Debt Securities, Available-for-sale [Line Items]
Ownership percentage	5.00%	5.00%
BeiGene | Other Noncurrent Assets | BeiGene
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 5,200,000,000		$ 3,500,000,000