Consolidated Balance Sheets (Parentheticals) (Unaudited) $ in Millions	Jun. 30, 2024 USD ($) shares	Dec. 31, 2023 USD ($) shares
Statement of Financial Position [Abstract]
Short-term investments amortized cost	$ 4,547	$ 4,551
Fixed maturities, available-for-sale, valuation allowance	122	156
Fixed maturities, available-for-sale, at amortized cost	113,529	111,128
Private debt held-to-maturity, amortized cost	5	4
Restricted cash	168	172
Premium Receivable, Allowance for Credit Loss	54	53
Valuation allowance for uncollectible reinsurance	$ 381	$ 367
Common Shares, shares issued | shares	419,625,986	431,451,586
Common Shares, shares outstanding | shares	404,073,495	405,269,637
Treasury Stock, Common, Shares | shares	15,552,491	26,181,949
Short-term investments	$ 4,546	$ 4,551
Equity securities	3,792	3,455
Private equities	14,365	14,078
Other Investments	7,513	5,527
Cash, including restricted cash	2,568	2,621
Other Assets	7,684	7,508
Repurchase agreements	3,149	2,833
Noncontrolling interests	$ 3,537	$ 4,184
Common Shares, shares issued | shares	419,625,986	431,451,586
Variable Interest Entity, Primary Beneficiary
Short-term investments	$ 42	$ 217
Equity securities	1,064	1,078
Private equities	22	21
Other Investments	3,955	3,773
Cash, including restricted cash	113	117
Other Assets	46	33
Other liabilities	33	18
Repurchase agreements	1,087	1,009
Noncontrolling interests	$ 2,597	$ 2,705