Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2022		Dec. 31, 2021
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	$ 50,495		$ 60,749
Equity Method Investments, Fair Value Disclosure	137		151
Funds withheld at interest embedded derivatives	(197)		104
Cash and cash equivalents	2,114		1,138
Short-term investments	196		64
Derivative Assets (Liabilities), at Fair Value, Net			175
Investments, Fair Value Disclosure	184	[1]	227	[2]
Assets, Fair Value Disclosure	52,981		62,516
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	689		855
Funds Held under Reinsurance Agreements, Liability	(256)		(61)
Liabilities Fair Value Disclosure
Other liabilities			(39)
Financial Liabilities Fair Value Disclosure	731		833
Fair Value, Net Asset (Liability)	656		581
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	52		83
Other
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	23
Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	161
Liabilities Fair Value Disclosure
Other liabilities	(298)
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure			52
Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	32,655		38,103
Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	3,586		4,944
Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	953		1,050
Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	3,723		4,005
Assets, Fair Value Disclosure	196		205
Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,670		1,849
US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	863		2,105
Assets, Fair Value Disclosure	9		12
US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,086		1,323
Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	5,959		7,370
Fair Value Inputs Level 1 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	767		1,993
Equity Method Investments, Fair Value Disclosure	73		101
Funds withheld at interest embedded derivatives	0		0
Cash and cash equivalents	2,114		1,138
Short-term investments	141		0
Derivative Assets (Liabilities), at Fair Value, Net			0
Investments, Fair Value Disclosure	0	[1]	0	[2]
Assets, Fair Value Disclosure	3,095		3,232
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0		0
Funds Held under Reinsurance Agreements, Liability	0		0
Liabilities Fair Value Disclosure
Other liabilities			0
Financial Liabilities Fair Value Disclosure	0		0
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	0		0
Fair Value Inputs Level 1 Member | Other
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0
Fair Value Inputs Level 1 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 1 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure			0
Fair Value Inputs Level 1 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	767		1,993
Fair Value Inputs Level 1 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 1 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 2 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	44,184		53,611
Equity Method Investments, Fair Value Disclosure	0		0
Funds withheld at interest embedded derivatives	0		0
Cash and cash equivalents	0		0
Short-term investments	48		36
Derivative Assets (Liabilities), at Fair Value, Net			175
Investments, Fair Value Disclosure	184	[1]	227	[2]
Assets, Fair Value Disclosure	44,416		53,874
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0		0
Funds Held under Reinsurance Agreements, Liability	0		0
Liabilities Fair Value Disclosure
Other liabilities			(39)
Financial Liabilities Fair Value Disclosure	298		39
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	0		0
Fair Value Inputs Level 2 Member | Other
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	23
Fair Value Inputs Level 2 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	161
Liabilities Fair Value Disclosure
Other liabilities	(298)
Fair Value Inputs Level 2 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure			52
Fair Value Inputs Level 2 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	28,369		34,215
Fair Value Inputs Level 2 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	3,586		4,944
Fair Value Inputs Level 2 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	952		1,049
Fair Value Inputs Level 2 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,599		2,908
Fair Value Inputs Level 2 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,607		1,768
Fair Value Inputs Level 2 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	87		100
Fair Value Inputs Level 2 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,058		1,290
Fair Value Inputs Level 2 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	5,926		7,337
Fair Value Inputs Level 3 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	5,544		5,145
Equity Method Investments, Fair Value Disclosure	64		50
Funds withheld at interest embedded derivatives	(197)		104
Cash and cash equivalents	0		0
Short-term investments	7		28
Derivative Assets (Liabilities), at Fair Value, Net			0
Investments, Fair Value Disclosure	0	[1]	0	[2]
Assets, Fair Value Disclosure	5,470		5,410
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	689		855
Funds Held under Reinsurance Agreements, Liability	(256)		(61)
Liabilities Fair Value Disclosure
Other liabilities			0
Financial Liabilities Fair Value Disclosure	433		794
Funds Held Under Reinsurance Agreements, Asset Fair Value Disclosure	52		83
Fair Value Inputs Level 3 Member | Other
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0
Fair Value Inputs Level 3 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 3 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure			0
Fair Value Inputs Level 3 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	4,286		3,888
Fair Value Inputs Level 3 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0		0
Fair Value Inputs Level 3 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1		1
Fair Value Inputs Level 3 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,124		1,097
Fair Value Inputs Level 3 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	63		81
Fair Value Inputs Level 3 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	9		12
Fair Value Inputs Level 3 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	28		33
Fair Value Inputs Level 3 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	$ 33		$ 33

[1] Other invested assets included in the fair value hierarchy exclude limited partnership interests that are measured at estimated fair value using the net asset value (“NAV”) per share (or its equivalent) as a practical expedient. As of September 30, 2022, the fair value of such investments was $656 million.

[2] Other invested assets included in the fair value hierarchy exclude limited partnership interests 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