Investments (Commercial Mortgage Loans By Year Of Origination) (Details) - Commercial [Member] $ in Millions	Sep. 30, 2023 USD ($) item	Dec. 31, 2022 USD ($) item
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	$ 982	$ 1,876
Originated in prior year	1,855	2,407
Originated in two years prior	2,386	1,297
Originated in three years prior	1,233	2,753
Originated in four years prior	2,535	2,289
Originated in five years prior and prior	8,133	6,301
Total	17,124	16,923
Loan-to-value ratio, less than 65% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	934	1,769
Originated in prior year	1,766	2,335
Originated in two years prior	2,322	1,280
Originated in three years prior	1,222	2,643
Originated in four years prior	2,443	2,222
Originated in five years prior and prior	7,980	6,170
Total	$ 16,667	$ 16,419
Originated in current year | item	1.87	2.06
Originated in prior year | item	2.06	3.05
Originated in two years prior | item	3.36	2.99
Originated in three years prior | item	3.19	2.17
Originated in four years prior | item	2.44	2.17
Originated in five years prior and prior | item	2.42	2.44
Loan-to-value ratio, 65% to 75% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	$ 48	$ 105
Originated in prior year	88	72
Originated in two years prior	64	17
Originated in three years prior	11	81
Originated in four years prior	82	67
Originated in five years prior and prior	152	131
Total	$ 445	$ 473
Originated in current year | item	1.42	1.50
Originated in prior year | item	2.06	1.53
Originated in two years prior | item	1.57	1.58
Originated in three years prior | item	1.50	1.50
Originated in four years prior | item	1.48	1.62
Originated in five years prior and prior | item	1.59	1.75
Loan-to-value ratio, 75% to 100% [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year		$ 2
Originated in prior year	$ 1
Originated in three years prior		29
Originated in four years prior	10
Originated in five years prior and prior	1
Total	$ 12	$ 31
Originated in current year | item		1.45
Originated in prior year | item	1.13
Originated in three years prior | item		1.58
Originated in four years prior | item	2.33
Originated in five years prior and prior | item	1.67