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Short Duration Contracts - Claims development - Insurance (Details) $ in Thousands | Dec. 31, 2020 USD ($) claims | Dec. 31, 2019 USD ($) | 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 ($) | Dec. 31, 2011 USD ($)
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Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Liabilities for losses and loss adjustment expenses, net of reinsurance | $ 11,923,393 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | 1,766,001 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 1,296,930 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2008, net of reinsurance | 23,517 |  |  |  |  |  |  |  |  |
Liabilities for losses and loss adjustment expenses, net of reinsurance | 492,588 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2011 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | 196,436 | $ 197,833 | $ 201,198 | $ 200,918 | $ 207,814 | $ 210,926 | $ 220,231 | $ 231,841 | $ 272,897 | $ 269,739
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 195,347 | 195,245 | 198,626 | 197,720 | 202,347 | 200,473 | 167,867 | 142,231 | 99,724 | 34,478
Total of IBNR liabilities plus expected development on reported claims | $ 689 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 4,219 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 177,673 | 178,039 | 190,192 | 192,406 | 196,405 | 198,837 | 205,098 | 231,742 | 232,500 |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 173,460 | 172,611 | 180,734 | 179,371 | 166,965 | 161,255 | 138,431 | 92,855 | 20,522 |
Total of IBNR liabilities plus expected development on reported claims | $ 931 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 4,269 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 126,968 | 128,301 | 133,544 | 134,620 | 143,046 | 148,800 | 156,344 | 158,718 |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 124,369 | 123,036 | 125,156 | 121,922 | 119,791 | 110,548 | 84,759 | 32,239 |  |
Total of IBNR liabilities plus expected development on reported claims | $ 809 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 4,278 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 134,937 | 134,234 | 132,209 | 136,096 | 147,315 | 145,765 | 148,185 |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 115,293 | 98,463 | 87,721 | 84,103 | 77,804 | 53,669 | 25,859 |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 4,206 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 3,930 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 91,788 | 97,809 | 102,469 | 103,944 | 109,799 | 112,333 |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 86,207 | 87,887 | 86,214 | 76,299 | 64,916 | 23,567 |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 5,249 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 4,618 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 96,127 | 100,147 | 105,330 | 100,986 | 104,139 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 94,703 | 97,218 | 98,420 | 83,321 | 24,728 |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 882 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 6,389 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 230,421 | 235,932 | 246,272 | 280,695 |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 211,694 | 195,518 | 139,854 | 30,219 |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 9,327 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 6,752 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 173,693 | 186,030 | 180,981 |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 134,858 | 102,285 | 30,026 |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 14,784 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 5,347 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 178,564 | 179,056 |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 105,380 | 26,130 |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 20,553 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 6,051 |  |  |  |  |  |  |  |  |
Insurance | Property, energy, marine and aviation | 2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 359,394 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 55,619 |  |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 168,463 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 16,980 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 3,802,970 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 1,453,716 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2008, net of reinsurance | 209,031 |  |  |  |  |  |  |  |  |
Liabilities for losses and loss adjustment expenses, net of reinsurance | 2,558,285 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2011 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | 235,073 | 234,782 | 239,676 | 247,052 | 253,976 | 252,615 | 258,784 | 254,181 | 240,669 | 234,068
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 181,505 | 172,940 | 160,609 | 152,756 | 134,622 | 113,502 | 73,448 | 43,479 | 25,276 | 7,020
Total of IBNR liabilities plus expected development on reported claims | $ 35,138 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 70,924 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 241,378 | 243,484 | 242,930 | 252,822 | 257,418 | 271,035 | 268,365 | 262,718 | 241,062 |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 162,202 | 154,282 | 143,177 | 129,572 | 108,252 | 83,328 | 58,444 | 30,824 | 6,966 |
Total of IBNR liabilities plus expected development on reported claims | $ 50,208 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 65,495 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 269,437 | 272,528 | 274,391 | 281,786 | 301,789 | 306,751 | 296,839 | 282,968 |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 174,700 | 164,187 | 149,098 | 122,120 | 101,196 | 71,370 | 29,230 | 6,845 |  |
Total of IBNR liabilities plus expected development on reported claims | $ 60,720 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 66,685 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 342,731 | 343,995 | 339,495 | 342,868 | 338,623 | 335,720 | 329,809 |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 211,503 | 191,168 | 161,993 | 112,591 | 71,519 | 40,263 | 9,209 |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 77,547 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 74,964 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 382,518 | 391,231 | 391,904 | 398,670 | 391,666 | 358,858 |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 211,573 | 181,566 | 139,403 | 88,443 | 44,542 | 11,119 |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 107,083 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 77,257 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 374,728 | 399,394 | 405,889 | 394,281 | 389,623 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 164,573 | 136,793 | 87,565 | 41,938 | 11,689 |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 142,000 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 76,765 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 412,318 | 422,441 | 417,748 | 417,183 |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 135,025 | 99,827 | 52,323 | 13,396 |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 195,684 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 82,267 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 450,736 | 452,975 | 430,216 |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 115,076 | 63,798 | 17,002 |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 248,271 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 74,789 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 487,224 | 456,059 |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 73,120 | 18,392 |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 318,622 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 80,934 |  |  |  |  |  |  |  |  |
Insurance | Third party occurrence business | 2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 606,827 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 24,439 |  |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 524,473 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 67,541 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 3,042,469 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 1,763,247 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2008, net of reinsurance | 97,957 |  |  |  |  |  |  |  |  |
Liabilities for losses and loss adjustment expenses, net of reinsurance | 1,377,179 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2011 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | 290,124 | 291,477 | 289,974 | 288,038 | 301,240 | 322,934 | 317,074 | 322,274 | 330,898 | 287,607
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 276,887 | 269,579 | 254,300 | 240,267 | 228,450 | 208,665 | 175,139 | 130,424 | 72,365 | 13,740
Total of IBNR liabilities plus expected development on reported claims | $ 4,594 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 11,762 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 285,236 | 284,875 | 277,388 | 275,388 | 291,010 | 313,622 | 318,161 | 319,961 | 317,360 |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 255,098 | 251,078 | 227,179 | 209,097 | 190,200 | 164,605 | 121,112 | 69,020 | 17,709 |
Total of IBNR liabilities plus expected development on reported claims | $ 13,772 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 14,760 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 271,262 | 281,751 | 290,961 | 294,465 | 320,284 | 324,167 | 320,387 | 301,715 |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 245,504 | 238,798 | 217,030 | 197,907 | 179,302 | 137,890 | 87,408 | 19,015 |  |
Total of IBNR liabilities plus expected development on reported claims | $ 15,306 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 14,543 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 291,729 | 297,485 | 281,513 | 278,706 | 298,715 | 279,544 | 264,354 |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 243,338 | 229,512 | 207,640 | 172,835 | 129,502 | 63,296 | 13,815 |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 29,279 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 13,935 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 252,329 | 255,276 | 259,902 | 276,328 | 277,437 | 258,817 |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 193,130 | 174,108 | 126,452 | 100,048 | 52,019 | 9,061 |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 29,255 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 13,817 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 321,850 | 314,515 | 308,195 | 291,377 | 275,119 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 205,514 | 158,159 | 127,229 | 68,178 | 10,547 |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 61,156 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 15,734 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 308,401 | 311,980 | 285,993 | 270,523 |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 143,149 | 113,047 | 67,572 | 9,289 |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 82,537 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 15,923 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 319,956 | 314,412 | 272,844 |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 118,184 | 68,300 | 12,255 |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 123,386 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 14,988 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 317,668 | 289,463 |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 65,345 | 12,387 |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 186,452 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 18,871 |  |  |  |  |  |  |  |  |
Insurance | Third party claims-made business | 2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 383,914 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 17,098 |  |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 327,587 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 21,538 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 4,676,493 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 3,434,155 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2008, net of reinsurance | 31,453 |  |  |  |  |  |  |  |  |
Liabilities for losses and loss adjustment expenses, net of reinsurance | 1,273,791 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2011 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | 166,577 | 170,091 | 170,350 | 168,888 | 172,403 | 172,649 | 176,545 | 182,979 | 188,766 | 183,081
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 162,995 | 162,460 | 159,526 | 157,199 | 151,710 | 148,049 | 136,686 | 117,927 | 103,372 | $ 51,312
Total of IBNR liabilities plus expected development on reported claims | $ 1,790 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 44,989 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2012 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 244,246 | 244,191 | 247,279 | 247,050 | 255,277 | 256,106 | 258,467 | 264,217 | 253,525 |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 239,244 | 236,282 | 232,987 | 231,776 | 222,929 | 209,124 | 190,064 | 165,836 | $ 78,337 |
Total of IBNR liabilities plus expected development on reported claims | $ 2,551 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 55,512 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2013 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 270,853 | 273,177 | 275,386 | 271,687 | 281,697 | 274,483 | 283,112 | 274,361 |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 260,374 | 257,744 | 251,698 | 237,898 | 222,086 | 185,611 | 152,773 | $ 86,791 |  |
Total of IBNR liabilities plus expected development on reported claims | $ 4,661 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 72,323 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2014 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 418,512 | 410,366 | 398,240 | 387,082 | 370,442 | 373,978 | 349,754 |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 380,041 | 367,026 | 341,580 | 306,411 | 255,332 | 206,444 | $ 109,236 |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 12,232 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 111,727 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2015 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 471,865 | 456,329 | 443,258 | 420,642 | 418,761 | 398,755 |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 409,455 | 380,818 | 350,781 | 304,197 | 250,360 | $ 142,009 |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 18,596 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 151,598 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2016 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 537,591 | 516,239 | 514,650 | 504,586 | 482,653 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 464,774 | 425,642 | 382,805 | 323,681 | $ 181,415 |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 28,282 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 177,931 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2017 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 615,833 | 578,341 | 579,217 | 551,688 |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 480,336 | 419,454 | 363,275 | $ 187,606 |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 45,947 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 221,643 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2018 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 629,299 | 621,534 | 570,069 |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 464,970 | 399,852 | $ 214,475 |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 74,894 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 247,622 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2019 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 667,415 | 613,638 |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 397,104 | $ 213,950 |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 134,996 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 234,383 |  |  |  |  |  |  |  |  |
Insurance | Multi-line and other specialty | 2020 |  |  |  |  |  |  |  |  |  |
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] |  |  |  |  |  |  |  |  |  |
Incurred losses and allocated loss adjustment expenses, net of reinsurance | $ 654,302 |  |  |  |  |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance | 174,862 |  |  |  |  |  |  |  |  |
Total of IBNR liabilities plus expected development on reported claims | $ 403,044 |  |  |  |  |  |  |  |  |
Cumulative number of reported claims | claims | 117,814 |  |  |  |  |  |  |  |  |

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