Investments - Total Investment Schedule (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Total Investments [Line Items]
Current	$ 2,973	$ 3,117
Long-term	22,595	23,025
Total	25,568	26,142
Thailand Business
Total Investments [Line Items]
Current investments accounted for as assets held for sale	73
Debt securities available for sale
Total Investments [Line Items]
Current	2,826	3,009
Long-term	19,672	20,231
Total	22,498	23,240
Mortgage loans
Total Investments [Line Items]
Current	114	58
Long-term	804	844
Total	918	902
Other investments
Total Investments [Line Items]
Current	33	50
Long-term	2,119	1,950
Total	$ 2,152	$ 2,000