Statement of Financial Position (Parentheticals) $ in Millions	Mar. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($) shares
Statement of Financial Position [Abstract]
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 27	$ 14
Available for sale, at amortized cost	91,526	90,493
Debt Securities, Held-to-maturity, Allowance for Credit Loss	34	35
Held to maturity, Fair Value	9,888	10,647
short-term investments amortized cost	3,408	3,147
Premium Receivable, Allowance for Credit Loss	50	46
Reinsurance Recoverable, Allowance for Credit Loss	$ 329	$ 329
Common Shares, shares issued | shares	459,555,714	474,021,114
Common Shares, shares outstanding | shares	423,675,327	426,572,612
Common Shares in treasury, shares | shares	35,880,387	47,448,502