Investments - Total Investment Schedule (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Total Investments [Line Items]
Current	$ 3,102	$ 2,778
Long-term	21,612	21,113
Total	24,714	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	3,061	2,718
Long-term	17,761	17,562
Total	20,822	20,280
Mortgage loans
Total Investments [Line Items]
Current	39	55
Long-term	1,038	989
Total	1,077	1,044
Other investments
Total Investments [Line Items]
Current	2	5
Long-term	2,813	2,562
Total	$ 2,815	$ 2,567