Investments Investments (Allowance for Credit Loss Roll Forward) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 132	$ 111	$ 132	$ 111	$ 103	$ 98	$ 95	$ 75
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not Previously Recorded	35	2	45	32
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Securities Sold	0	(1)	(2)	(9)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)	(6)	14	(8)	12
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation	0	0	(1)	0
Allowance for Loan and Lease Losses, Real Estate	107	75	107	75	89	93	77	67
Allowance For Loan and Lease Losses Provision Of Credit Losses	18	6	14	16
Provision (release)	0	(8)	0	(8)
Commercial Real Estate
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Allowance for Loan and Lease Losses, Real Estate	103	75	103	75	87	93	77	67
Allowance For Loan and Lease Losses Provision Of Credit Losses	16	6	10	16
Provision (release)	0	(8)	0	(8)
Residential Real Estate
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Allowance for Loan and Lease Losses, Real Estate	4	0	4	0	2	0	0	0
Allowance For Loan and Lease Losses Provision Of Credit Losses	2	0	4	0
Provision (release)	0	0	0	0
Corporate Debt Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	112	95	112	95	88	82	79	62
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not Previously Recorded	31	2	41	32
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Securities Sold	0	(1)	(2)	(9)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)	(7)	14	(8)	9
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation	0	0	(1)	0
Asset-backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	19	15	19	15	15	15	15	12
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not Previously Recorded	4	0	4	0
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Securities Sold	0	0	0	0
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)	0	0	0	(3)
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation	0	0	0	0
Commercial Mortgage Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	1	1	1	1	$ 0	1	$ 1	$ 1
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not Previously Recorded	0	0	0	0
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Securities Sold	0	0	0	0
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)	1	0	0	0
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation	0	0	0	0
Debt Security, Government, Non-US [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0		0			$ 0
Available-for-sale Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense	0	1	0	1
Available-for-sale Securities [Member] | Corporate Debt Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense	0	1	0	1
Available-for-sale Securities [Member] | Asset-backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense	0	0	0	0
Available-for-sale Securities [Member] | Commercial Mortgage Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense	$ 0	$ 0	$ 0	$ 0