| **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** | Sep. 30, 2022 | Dec. 31, 2021 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | $ 953         | $ 973         |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | 2,780         | 2,779         |
| Carrying Amount                                                                                                                                                                 |          |          |
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | 953           | 973           |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | 2,780         | 2,779         |
| Estimated Fair Value                                                                                                                                                            |          |          |
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | 880           | 1,018         |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | 2,563         | 2,978         |
| Level 1 | Estimated Fair Value                                                                                                                                                  |          |          |
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | 0             | 0             |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | 0             | 0             |
| Level 2 | Estimated Fair Value                                                                                                                                                  |          |          |
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | 0             | 0             |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | 2,563         | 2,978         |
| Level 3 | Estimated Fair Value                                                                                                                                                  |          |          |
| **Assets**                                                                                                                                                                      |          |          |
| Mortgage loans                                                                                                                                                                  | 880           | 1,018         |
| **Liabilities**                                                                                                                                                                 |          |          |
| Long term debt                                                                                                                                                                  | $ 0           | $ 0           |

| X                                                                                                                                                                                                                                          |
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| - References
No definition available.
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| - References
No definition available.
+ Details**Name:**us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt classified as noncurrent. Excludes lease obligation.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The 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.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(c)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910
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| X                                                                                                                                                                                       |
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