Investments (Exposure To Concentrations Of Credit Risk) (Details) - USD ($) $ in Millions	Jun. 30, 2023		Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	$ 62,185		$ 59,663
Fixed maturity securities, available-for-sale	56,236	[1]	52,901	[2]
Canadian Province Of Quebec Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	1,432		1,436
Fixed maturity securities, available-for-sale	1,668		1,649
Canadian Province Of Ontario Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	1,014		982
Fixed maturity securities, available-for-sale	$ 1,104		$ 1,068

[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 June 30, 2023, the fair value of such investments was $768 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, 2022, the fair value of such investments was $683 million