Investments - Total Investments Schedule (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Total Investments [Line Items]
Current	$ 3,259	$ 2,778
Long-term	23,019	21,096
Long-term		21,113
Total	26,278	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	3,131	2,718
Long-term	18,582
Long-term		17,562
Total	21,713	20,280
Mortgage loans
Total Investments [Line Items]
Current	128	55
Long-term	1,183
Long-term		989
Total	1,311	1,044
Other investments
Total Investments [Line Items]
Current	0	5
Long-term	3,254
Long-term		2,562
Total	$ 3,254	$ 2,567