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Claim, Claim Adjustment Expense and Future Policy Benefit Reserves (International - Excluding Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - Excluding Hardy - International $ in Millions | Dec. 31, 2021 USD ($) claim | Dec. 31, 2020 USD ($) | 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 ($) | Dec. 31, 2012 USD ($)
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Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 3,371 |  |  |  |  |  |  |  |  |
IBNR | 845 |  |  |  |  |  |  |  |  |
2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | 250 | $ 236 | $ 241 | $ 247 | $ 254 | $ 261 | $ 262 | $ 269 | $ 285 | $ 278
IBNR | $ 16 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 24,998 |  |  |  |  |  |  |  |  |
2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 251 | 247 | 251 | 260 | 269 | 273 | 293 | 301 | $ 285 |
IBNR | $ 12 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 23,967 |  |  |  |  |  |  |  |  |
2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 294 | 301 | 300 | 283 | 291 | 303 | 303 | $ 288 |  |
IBNR | $ 16 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 24,946 |  |  |  |  |  |  |  |  |
2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 297 | 294 | 292 | 298 | 316 | 317 | $ 301 |  |  |
IBNR | $ 27 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 23,357 |  |  |  |  |  |  |  |  |
2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 302 | 287 | 297 | 300 | 315 | $ 296 |  |  |  |
IBNR | $ 37 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 17,776 |  |  |  |  |  |  |  |  |
2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 388 | 393 | 401 | 378 | $ 312 |  |  |  |  |
IBNR | $ 84 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 18,470 |  |  |  |  |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 406 | 407 | 402 | $ 384 |  |  |  |  |  |
IBNR | $ 81 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 20,726 |  |  |  |  |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 368 | 371 | $ 357 |  |  |  |  |  |  |
IBNR | $ 91 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 17,974 |  |  |  |  |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 389 | $ 398 |  |  |  |  |  |  |  |
IBNR | $ 184 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 13,909 |  |  |  |  |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 426 |  |  |  |  |  |  |  |  |
IBNR | $ 297 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 10,401 |  |  |  |  |  |  |  |  |

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