|**Fair Value (Carrying amount and estimated fair value of financial instrument assets and liabilities which are not measured at fair value) (Details) - USD ($) $ in Millions**                                                                                                                                                                                                                                                                                                        | Dec. 31, 2023                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | Dec. 31, 2022                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | $ 1,035                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | $ 1,040                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 2,481                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 2,538                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Carrying Amount                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 1,035                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 1,040                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Short-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 550                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 243                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 2,481                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 2,538                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Estimated Fair Value                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 997                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 973                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Short-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 546                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 248                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 2,385                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 2,349                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Level 1 | Estimated Fair Value                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Short-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Level 2 | Estimated Fair Value                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Short-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 546                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 248                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 2,385                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | 2,349                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Level 3 | Estimated Fair Value                                                                                                                                                                                                                                                                                                                                                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|**Assets**                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Mortgage loans                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 997                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | 973                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Liabilities**                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Short-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Long-term debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | $ 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | $ 0                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|[1]
As of January 1, 2023, the Company adopted ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts(ASU 2018-12) using the modified retrospective method applied as of the transition date of January 1, 2021.  Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance.  See Note A to the Consolidated Financial Statements for additional information. | [1]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | As of January 1, 2023, the Company adopted ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts(ASU 2018-12) using the modified retrospective method applied as of the transition date of January 1, 2021.  Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance.  See Note A to the Consolidated Financial Statements for additional information.
|[1]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | As of January 1, 2023, the Company adopted ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts(ASU 2018-12) using the modified retrospective method applied as of the transition date of January 1, 2021.  Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance.  See Note A to the Consolidated Financial Statements for additional information.

X- ReferencesNo definition available.
+ Details**Name:**
us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- ReferencesNo definition available.
+ Details**Name:**
us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionAmount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt classified as noncurrent. Excludes lease obligation.
+ ReferencesReference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1
+ Details**Name:**
us-gaap_LongTermDebtNoncurrent**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:monetaryItemType**Balance Type:**
credit**Period Type:**
instant X- DefinitionThe balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.
+ ReferencesReference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(c)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1
+ Details**Name:**
us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:monetaryItemType**Balance Type:**
debit**Period Type:**
instant X- DefinitionThis element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.
+ ReferencesNo definition available.
+ Details**Name:**
us-gaap_ShorttermDebtFairValue**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:monetaryItemType**Balance Type:**
credit**Period Type:**
instant X- Details**Name:**
us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember**Namespace Prefix:****Data Type:**
na**Balance Type:****Period Type:** X- Details**Name:**
us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember**Namespace Prefix:****Data Type:**
na**Balance Type:****Period Type:** X- Details**Name:**
us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member**Namespace Prefix:****Data Type:**
na**Balance Type:****Period Type:** X- Details**Name:**
us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member**Namespace Prefix:****Data Type:**
na**Balance Type:****Period Type:** X- Details**Name:**
us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member**Namespace Prefix:****Data Type:**
na**Balance Type:****Period Type:**