Investments - Total Investment Schedule (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Total Investments [Line Items]
Current	$ 3,755	$ 3,259
Long-term	25,028	23,019
Total	28,783	26,278
Debt securities available for sale
Total Investments [Line Items]
Current	3,604	3,131
Long-term	20,227	18,582
Total	23,831	21,713
Mortgage loans
Total Investments [Line Items]
Current	151	128
Long-term	1,251	1,183
Total	1,402	1,311
Other investments
Total Investments [Line Items]
Current	0	0
Long-term	3,550	3,254
Total	$ 3,550	$ 3,254