Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022		Dec. 31, 2021
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	$ 52,901	[1]	$ 60,749	[2]
Equity Method Investments, Fair Value Disclosure	134	[1]	151	[2]
Fair Value Measured On Recurring Basis Funds Held Under Reinsurance Agreements Asset Embedded Derivatives	(370)	[1]	(104)	[2]
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	54	[1]	83	[2]
Cash and Cash Equivalents, Fair Value Disclosure	1,535	[1]	1,138	[2]
Fair Value Measured On Recurring Basis Short Term Investments	121	[1]	64	[2]
Derivative Assets (Liabilities), at Fair Value, Net	170	[1]	175	[2]
Investments, Fair Value Disclosure	193	[1]	227	[2]
Assets, Fair Value Disclosure	54,568	[1]	62,516	[2]
Liabilities, Fair Value Disclosure [Abstract]
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	653		855
Funds Held under Reinsurance Agreements, Liability	(361)		(61)
Other Liabilities, Fair Value Disclosure	183		39
Financial Liabilities Fair Value Disclosure	475		833
Fair Value, Net Asset (Liability)	683		581
Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,388	[1]	1,993	[2]
Equity Method Investments, Fair Value Disclosure	68	[1]	101	[2]
Fair Value Measured On Recurring Basis Funds Held Under Reinsurance Agreements Asset Embedded Derivatives	0	[1]	0	[2]
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	0	[1]	0	[2]
Cash and Cash Equivalents, Fair Value Disclosure	1,535	[1]	1,138	[2]
Fair Value Measured On Recurring Basis Short Term Investments	54	[1]	0	[2]
Derivative Assets (Liabilities), at Fair Value, Net	0	[1]	0	[2]
Investments, Fair Value Disclosure	0	[1]	0	[2]
Assets, Fair Value Disclosure	3,045	[1]	3,232	[2]
Liabilities, Fair Value Disclosure [Abstract]
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0		0
Funds Held under Reinsurance Agreements, Liability	0		0
Other Liabilities, Fair Value Disclosure	0
Financial Liabilities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	45,791	[1]	53,611	[2]
Equity Method Investments, Fair Value Disclosure	0	[1]	0	[2]
Fair Value Measured On Recurring Basis Funds Held Under Reinsurance Agreements Asset Embedded Derivatives	0	[1]	0	[2]
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	0	[1]	0	[2]
Cash and Cash Equivalents, Fair Value Disclosure	0	[1]	0	[2]
Fair Value Measured On Recurring Basis Short Term Investments	54	[1]	36	[2]
Derivative Assets (Liabilities), at Fair Value, Net	170	[1]	175	[2]
Investments, Fair Value Disclosure	193	[1]	227	[2]
Assets, Fair Value Disclosure	46,038	[1]	53,874	[2]
Liabilities, Fair Value Disclosure [Abstract]
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0		0
Funds Held under Reinsurance Agreements, Liability	0		0
Other Liabilities, Fair Value Disclosure	183
Financial Liabilities Fair Value Disclosure	183		39
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	5,722	[1]	5,145	[2]
Equity Method Investments, Fair Value Disclosure	66	[1]	50	[2]
Fair Value Measured On Recurring Basis Funds Held Under Reinsurance Agreements Asset Embedded Derivatives	(370)	[1]	(104)	[2]
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	54	[1]	83	[2]
Cash and Cash Equivalents, Fair Value Disclosure	0	[1]	0	[2]
Fair Value Measured On Recurring Basis Short Term Investments	13	[1]	28	[2]
Derivative Assets (Liabilities), at Fair Value, Net	0	[1]	0	[2]
Investments, Fair Value Disclosure	0	[1]	0	[2]
Assets, Fair Value Disclosure	5,485	[1]	5,410	[2]
Liabilities, Fair Value Disclosure [Abstract]
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	653		855
Funds Held under Reinsurance Agreements, Liability	(361)		(61)
Other Liabilities, Fair Value Disclosure	0
Financial Liabilities Fair Value Disclosure	292		794
Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Other Liabilities, Fair Value Disclosure			0
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Other Liabilities, Fair Value Disclosure			39
Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Other Liabilities, Fair Value Disclosure			0
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, Fair Value Disclosure	23	[1]	52	[2]
Fair Value Option Contractholder Directed Unit Linked Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, Fair Value Disclosure	0	[1]	0	[2]
Fair Value Option Contractholder Directed Unit Linked Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, Fair Value Disclosure	23	[1]	52	[2]
Fair Value Option Contractholder Directed Unit Linked Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, Fair Value Disclosure	0	[1]	0	[2]
Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	33,969	[1]	38,103	[2]
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	29,670	[1]	34,215	[2]
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	4,299	[1]	3,888	[2]
Canadian Provincial Governments [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,626	[1]	4,944	[2]
Canadian Provincial Governments [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Canadian Provincial Governments [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,626	[1]	4,944	[2]
Canadian Provincial Governments [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Residential Mortgage Backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	941	[1]	1,050	[2]
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	931	[1]	1,049	[2]
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	10	[1]	1	[2]
Asset-backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,878	[1]	4,005	[2]
Assets, Fair Value Disclosure	274		205
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	2,603	[1]	2,908	[2]
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,275	[1]	1,097	[2]
Commercial Mortgage Backed Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,623	[1]	1,849	[2]
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,555	[1]	1,768	[2]
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	68	[1]	81	[2]
US Treasury and Government [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,482	[1]	2,105	[2]
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,388	[1]	1,993	[2]
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	85	[1]	100	[2]
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	9	[1]	12	[2]
US States and Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,119	[1]	1,323	[2]
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,093	[1]	1,290	[2]
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	26	[1]	33	[2]
Debt Security, Government, Non-US [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	6,263	[1]	7,370	[2]
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	[1]	0	[2]
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	6,228	[1]	7,337	[2]
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	$ 35	[1]	$ 33	[2]

[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 December 31, 2022, the fair value of such investments was $683 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, 2021, the fair value of such investments was $581 million.