Investments (Exposure To Concentrations Of Credit Risk) (Details) - USD ($) $ in Millions	Mar. 31, 2025		Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	$ 89,709		$ 82,907
Fixed maturity securities, available-for-sale	84,507	[1]	77,617	[2]
Canadian Province Of Quebec Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	1,560		1,537
Fixed maturity securities, available-for-sale	1,773		1,741
Canadian Province Of Ontario Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	1,149		1,117
Fixed maturity securities, available-for-sale	$ 1,249		$ 1,207

[1] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of March 31, 2025, the fair value of such investments was $963 million.

[2] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of December 31, 2024, the fair value of such investments was $966 million