Investments (Residential Mortgage Loans By Year Of Origination) (Details) - Residential [Member] - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	$ 242	$ 184
Originated in prior year	152	366
Originated in two years prior	246	187
Originated in three years prior	125
Total	765	737
Performing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	241	176
Originated in prior year	149	315
Originated in two years prior	220	175
Originated in three years prior	121
Total	731	666
Nonperforming [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	1	8
Originated in prior year	3	51
Originated in two years prior	26	12
Originated in three years prior	4
Total	$ 34	$ 71