| **Claim and Claim Adjustment Expense Reserves and Future Policy Benefit Reserves (International - Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - International $ in Millions** | Dec. 31, 2022 USD ($) claim | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|
| Hardy                                                                                                                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 2,016                     |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | 349                         |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2013                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | 144                         | $ 141                 | $ 142                 | $ 142                 | $ 141                 | $ 138                 | $ 137                 | $ 136                 | $ 143                 | $ 127                 |
| IBNR                                                                                                                                                                                                             | $ 3                         |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 7,904,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2014                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 164                       | 165                   | 167                   | 169                   | 168                   | 167                   | 173                   | 180                   | 182                   |                  |
| IBNR                                                                                                                                                                                                             | $ (4)                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 8,530,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2015                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 177                       | 175                   | 174                   | 172                   | 174                   | 174                   | 175                   | 186                   |                  |                  |
| IBNR                                                                                                                                                                                                             | $ (2)                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 9,722,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2016                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 216                       | 215                   | 222                   | 220                   | 231                   | 240                   | 224                   |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 3                         |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 10,834,000,000              |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2017                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 249                       | 249                   | 242                   | 241                   | 248                   | 240                   |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 5                         |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 13,204,000,000              |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2018                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 303                       | 303                   | 298                   | 295                   | 264                   |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 26                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 15,185,000,000              |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2019                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 221                       | 214                   | 219                   | 216                   |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 37                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 11,374,000,000              |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2020                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 191                       | 197                   | 206                   |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 62                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 6,699,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2021                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 164                       | 174                   |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 83                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 3,384,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Hardy | 2022                                                                                                                                                                                                     |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 187                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 136                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 1,279,000,000               |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy                                                                                                                                                                                                  |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 3,309                     |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | 901                         |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2013                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | 235                         | 234                   | 231                   | 235                   | 243                   | 250                   | 255                   | 274                   | 281                   | $ 279                 |
| IBNR                                                                                                                                                                                                             | $ 11                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 23,971                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2014                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 279                       | 273                   | 282                   | 281                   | 264                   | 271                   | 282                   | 283                   | $ 268                 |                  |
| IBNR                                                                                                                                                                                                             | $ 13                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 24,962                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2015                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 277                       | 277                   | 275                   | 273                   | 278                   | 294                   | 295                   | $ 280                 |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 22                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 23,372                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2016                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 283                       | 281                   | 268                   | 277                   | 279                   | 292                   | $ 275                 |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 29                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 17,813                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2017                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 348                       | 359                   | 364                   | 371                   | 351                   | $ 290                 |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 57                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 18,498                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2018                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 390                       | 378                   | 379                   | 374                   | $ 357                 |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 67                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 20,849                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2019                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 348                       | 341                   | 344                   | $ 331                 |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 69                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 18,354                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2020                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 350                       | 360                   | $ 368                 |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 138                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 14,952                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2021                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 385                       | $ 396                 |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 201                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 13,580                      |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Excluding Hardy | 2022                                                                                                                                                                                           |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| **Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]**                                                                                                            |                        |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Incurred claims and allocated claim adjustment expense, net                                                                                                                                                      | $ 414                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| IBNR                                                                                                                                                                                                             | $ 294                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |
| Cumulative Number of Claims | claim                                                                                                                                                                              | 8,320                       |                  |                  |                  |                  |                  |                  |                  |                  |                  |

| X                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
[Line Items] for Net Incurred Claim and Claim Adjustment Expense [Table]
+ References
No definition available.
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| - Definition
Undiscounted amount, after reinsurance, of incurred-but-not-reported (IBNR) liabilities plus expected development on reported claims, for claims and allocated claim adjustment expense for short-duration insurance contracts. Excludes unallocated claim adjustment expense.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4E -URI https://asc.fasb.org/extlink&oid=116884468&loc=SL65671321-158438Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4D -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=116884468&loc=SL65671317-158438
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| - Definition
Undiscounted amount, after reinsurance, of incurred claims and allocated claim adjustment expense used in claims development for short-duration insurance contracts. Excludes unallocated claim adjustment expense.
+ References
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| - Definition
Cumulative number of reported claims for short-duration insurance contracts.
+ References
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