Investments - Total Investment Schedule (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Total Investments [Line Items]
Current	$ 2,877	$ 3,117
Long-term	21,124	23,025
Total	24,001	26,142
Debt securities available for sale
Total Investments [Line Items]
Current	2,775	3,009
Long-term	17,976	20,231
Total	20,751	23,240
Mortgage loans
Total Investments [Line Items]
Current	88	58
Long-term	905	844
Total	993	902
Other investments
Total Investments [Line Items]
Current	14	50
Long-term	2,243	1,950
Total	$ 2,257	$ 2,000