Investments (Residential Mortgage Loans By Year Of Origination) (Details) - Residential [Member] - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	$ 148	$ 184
Originated in prior year	179	366
Originated in two years prior	293	187
Originated in three years prior	142
Total	762	737
Performing [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year	148	176
Originated in prior year	175	315
Originated in two years prior	262	175
Originated in three years prior	136
Total	721	666
Nonperforming [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in current year		8
Originated in prior year	4	51
Originated in two years prior	31	12
Originated in three years prior	6
Total	$ 41	$ 71