Consolidated Balance Sheets (Parentheticals) $ in Millions	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares
Statement of Financial Position [Abstract]
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 14	$ 20
Fixed maturities available for sale, at amortized cost	90,493	85,188
Debt Securities, Held-to-maturity, Allowance for Credit Loss	35	44
Debt Securities, Held-to-maturity, Fair Value	10,647	12,510
short-term investments amortized cost	3,147	4,349
Premium Receivable, Allowance for Credit Loss	46	44
Valuation allowance for uncollectible reinsurance	$ 329	$ 314
Common Shares, shares issued | shares	474,021,114	477,605,264
Common Shares, shares outstanding | shares	426,572,612	450,732,625
Treasury Stock, Shares | shares	47,448,502	26,872,639