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Claim, Claim Adjustment Expense and Future Policy Benefit Reserves (International - Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - 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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Hardy |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 2,008 |  |  |  |  |  |  |  |  |
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented | 529 |  |  |  |  |  |  |  |  |
IBNR | 297 |  |  |  |  |  |  |  |  |
Hardy | 2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Net Claim and Allocated Claim Adjustment Expense Reserves at Acquisition |  |  |  |  |  |  |  |  |  | $ 34
Incurred claims and allocated claim adjustment expense, net | 114 | $ 113 | $ 115 | $ 116 | $ 114 | $ 113 | $ 120 | $ 112 | $ 105 | 71
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented |  |  |  |  |  |  |  |  |  | 105
IBNR | $ (3) |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 7,045,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 144 | 146 | 146 | 145 | 142 | 140 | 139 | 147 | 132 |
IBNR | $ 7 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 7,893,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 169 | 172 | 173 | 172 | 171 | 178 | 184 | 186 |  |
IBNR | $ (6) |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 8,493,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 181 | 180 | 178 | 180 | 179 | 181 | 191 |  |  |
IBNR | $ (1) |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 9,669,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 222 | 228 | 226 | 238 | 249 | 231 |  |  |  |
IBNR | $ (1) |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 10,746,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 253 | 246 | 244 | 256 | 246 |  |  |  |  |
IBNR | $ 8 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 13,029,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 316 | 310 | 306 | 275 |  |  |  |  |  |
IBNR | $ 36 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 14,868,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 223 | 228 | 224 |  |  |  |  |  |  |
IBNR | $ 42 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 10,891,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 205 | 215 |  |  |  |  |  |  |  |
IBNR | $ 87 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 5,963,000,000 |  |  |  |  |  |  |  |  |
Hardy | 2021 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 181 |  |  |  |  |  |  |  |  |
IBNR | $ 128 |  |  |  |  |  |  |  |  |
Cumulative Number of Claims | claim | 2,244,000,000 |  |  |  |  |  |  |  |  |
Excluding Hardy |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred claims and allocated claim adjustment expense, net | $ 3,371 |  |  |  |  |  |  |  |  |
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented | 1,318 |  |  |  |  |  |  |  |  |
IBNR | 845 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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 |  |  |  |  |  |  |  |  |
Excluding Hardy | 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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