Investments - Total Investment Schedule (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Total Investments [Line Items]
Current	$ 3,145	$ 2,778
Long-term	21,667	21,113
Total	24,812	23,891
Disposal Group, Held-for-sale, Not Discontinued Operations
Total Investments [Line Items]
Long-term		17
Debt securities available for sale
Total Investments [Line Items]
Current	3,027	2,718
Long-term	17,374	17,562
Total	20,401	20,280
Mortgage loans
Total Investments [Line Items]
Current	116	55
Long-term	1,157	989
Total	1,273	1,044
Other investments
Total Investments [Line Items]
Current	2	5
Long-term	3,136	2,562
Total	$ 3,138	$ 2,567