| **Schedule V. Valuation and Qualifying Accounts (Schedule of valuation and qualifying accounts) (Details) - USD ($) $ in Millions** | 12 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| Mortgage loan receivables                                                                                                           |            |   |   |
| **Movement in valuation allowances and reserves [Roll Forward]**                                                                    |            |   |   |
| Balance Beginning of Period                                                                                                         | $ 26            | $ 7 |   |
| Charged to Costs and Expenses                                                                                                       | 0               | 0 |   |
| Charged to Other Accounts                                                                                                           | (10)            | 19 |   |
| Deductions                                                                                                                          | 0               | 0 |   |
| Balance at End of Period                                                                                                            | 16              | 26 | $ 7 |
| Insurance and reinsurance receivables                                                                                               |            |   |   |
| **Movement in valuation allowances and reserves [Roll Forward]**                                                                    |            |   |   |
| Balance Beginning of Period                                                                                                         | 54              | 57 | 71 |
| Charged to Costs and Expenses                                                                                                       | 4               | 4 | (6) |
| Charged to Other Accounts                                                                                                           | 0               | 0 | 0 |
| Deductions                                                                                                                          | (8)             | (7) | (8) |
| Balance at End of Period                                                                                                            | 50              | 54 | 57 |
| Fixed maturity securities                                                                                                           |            |   |   |
| **Movement in valuation allowances and reserves [Roll Forward]**                                                                    |            |   |   |
| Balance Beginning of Period                                                                                                         | 40              | 6 |   |
| Charged to Costs and Expenses                                                                                                       | 0               | 0 |   |
| Charged to Other Accounts                                                                                                           | 30              | 92 |   |
| Deductions                                                                                                                          | (52)            | (58) |   |
| Balance at End of Period                                                                                                            | $ 18            | $ 40 | $ 6 |

| X                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
+ References
No definition available.
+ Details**Name:**us-gaap_MovementInValuationAllowancesAndReservesRollForward**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of valuation and qualifying accounts and reserves.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690
+ Details**Name:**us-gaap_ValuationAllowancesAndReservesBalance**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(1)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690
+ Details**Name:**us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(2)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690
+ Details**Name:**us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of decrease in valuation and qualifying accounts and reserves.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690
+ Details**Name:**us-gaap_ValuationAllowancesAndReservesDeductions**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForLoanAndLeaseLossesRealEstateMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForReceivableFromInsuranceProviderMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForCreditLossMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |