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RESERVE FOR LOSSES AND LOSS EXPENSES - Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
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Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | $ 8,862,564 |  |  |  |  |  |  |  |  |
Insurance |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 3,534,458 |  |  |  |  |  |  |  |  |
Insurance | Property and other |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 3,371,989 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 6,225 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 579,613 |  |  |  |  |  |  |  |  |
Insurance | Property and other | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 110,970 | $ 110,990 | $ 110,656 | $ 110,612 | $ 110,819 | $ 110,745 | $ 106,531 | $ 95,726 | $ 87,604 | $ 48,995
Insurance | Property and other | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 272,372 | 272,402 | 271,960 | 271,287 | 271,483 | 272,530 | 250,251 | 193,949 | 85,346 |
Insurance | Property and other | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 315,703 | 313,602 | 313,529 | 308,368 | 300,845 | 277,909 | 213,961 | 77,461 |  |
Insurance | Property and other | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 264,607 | 262,819 | 259,787 | 248,746 | 237,714 | 198,955 | 75,831 |  |  |
Insurance | Property and other | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 318,866 | 317,697 | 313,360 | 306,221 | 259,679 | 132,872 |  |  |  |
Insurance | Property and other | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 242,270 | 241,586 | 227,237 | 202,649 | 99,120 |  |  |  |  |
Insurance | Property and other | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 338,243 | 329,709 | 289,711 | 123,640 |  |  |  |  |  |
Insurance | Property and other | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 744,285 | 628,364 | 253,400 |  |  |  |  |  |  |
Insurance | Property and other | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 577,243 | 284,651 |  |  |  |  |  |  |  |
Insurance | Property and other | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 187,430 |  |  |  |  |  |  |  |  |
Insurance | Marine |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 673,651 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 4,296 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 350,692 |  |  |  |  |  |  |  |  |
Insurance | Marine | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 43,377 | 43,372 | 43,286 | 46,918 | 45,944 | 45,159 | 42,325 | 33,296 | 28,603 | 18,017
Insurance | Marine | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 67,523 | 67,046 | 65,000 | 60,689 | 59,976 | 58,132 | 55,029 | 44,274 | 26,453 |
Insurance | Marine | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 55,950 | 54,863 | 52,841 | 50,448 | 49,631 | 44,884 | 38,594 | 10,708 |  |
Insurance | Marine | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 76,900 | 76,753 | 65,717 | 63,034 | 54,777 | 43,958 | 18,856 |  |  |
Insurance | Marine | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 40,895 | 36,020 | 26,930 | 26,905 | 15,179 | 6,357 |  |  |  |
Insurance | Marine | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 112,617 | 111,212 | 108,312 | 54,958 | 21,433 |  |  |  |  |
Insurance | Marine | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 63,333 | 57,314 | 31,817 | 12,487 |  |  |  |  |  |
Insurance | Marine | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 92,773 | 68,411 | 14,515 |  |  |  |  |  |  |
Insurance | Marine | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 84,834 | 25,153 |  |  |  |  |  |  |  |
Insurance | Marine | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 35,449 |  |  |  |  |  |  |  |  |
Insurance | Aviation |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 211,595 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 7,260 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 86,940 |  |  |  |  |  |  |  |  |
Insurance | Aviation | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 8,574 | 8,391 | 8,198 | 8,109 | 7,666 | 7,548 | 6,883 | 6,309 | 4,126 | 1,032
Insurance | Aviation | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 6,222 | 6,177 | 6,035 | 5,814 | 5,564 | 5,030 | 4,513 | 2,822 | 639 |
Insurance | Aviation | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 7,102 | 7,166 | 7,053 | 6,831 | 5,948 | 4,152 | 2,861 | 954 |  |
Insurance | Aviation | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 14,487 | 14,167 | 13,560 | 11,450 | 9,749 | 7,328 | 4,400 |  |  |
Insurance | Aviation | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 14,848 | 14,485 | 13,849 | 11,692 | 8,023 | 3,988 |  |  |  |
Insurance | Aviation | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 24,676 | 23,217 | 20,959 | 16,159 | 8,085 |  |  |  |  |
Insurance | Aviation | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 27,820 | 26,259 | 19,279 | 10,412 |  |  |  |  |  |
Insurance | Aviation | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 50,642 | 40,159 | 21,105 |  |  |  |  |  |  |
Insurance | Aviation | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 40,368 | 21,442 |  |  |  |  |  |  |  |
Insurance | Aviation | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 16,856 |  |  |  |  |  |  |  |  |
Insurance | Credit and political risk |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 294,917 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | (2,588) |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 98,219 |  |  |  |  |  |  |  |  |
Insurance | Credit and political risk | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 101,262 | 102,522 | 102,203 | 102,157 | 101,951 | 101,789 | 106,768 | 90,729 | 85,418 | 50,000
Insurance | Credit and political risk | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 27,636 | 27,636 | 27,636 | 27,636 | 27,636 | 27,636 | 27,636 | 37,205 | 32,788 |
Insurance | Credit and political risk | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 43 | 43 | 41 | 39 | 0 | 0 | 0 | 0 |  |
Insurance | Credit and political risk | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 13,828 | 13,828 | 11,769 | 5,216 | 3,726 | 2,235 | 745 |  |  |
Insurance | Credit and political risk | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 64,050 | 57,858 | 57,858 | 61,108 | 39,952 | 1,924 |  |  |  |
Insurance | Credit and political risk | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 23,309 | 23,309 | 23,309 | 23,309 | 0 |  |  |  |  |
Insurance | Credit and political risk | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 24,697 | 24,697 | 24,697 | 0 |  |  |  |  |  |
Insurance | Credit and political risk | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 11,019 | 5,593 | 1,523 |  |  |  |  |  |  |
Insurance | Credit and political risk | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 13,545 | 4,937 |  |  |  |  |  |  |  |
Insurance | Credit and political risk | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 15,528 |  |  |  |  |  |  |  |  |
Insurance | Professional lines |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 1,875,919 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 65,486 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 1,680,272 |  |  |  |  |  |  |  |  |
Insurance | Professional lines | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 142,788 | 136,510 | 114,520 | 109,540 | 99,039 | 88,558 | 72,592 | 53,493 | 27,806 | 7,807
Insurance | Professional lines | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 302,151 | 294,678 | 283,510 | 238,401 | 165,806 | 108,598 | 74,461 | 32,897 | 7,402 |
Insurance | Professional lines | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 281,715 | 273,383 | 253,958 | 230,913 | 184,191 | 100,089 | 41,328 | 7,818 |  |
Insurance | Professional lines | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 263,325 | 242,860 | 213,225 | 175,835 | 129,671 | 73,077 | 17,690 |  |  |
Insurance | Professional lines | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 242,899 | 223,838 | 192,405 | 130,039 | 70,662 | 23,529 |  |  |  |
Insurance | Professional lines | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 203,542 | 169,555 | 137,738 | 67,725 | 20,197 |  |  |  |  |
Insurance | Professional lines | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 192,459 | 147,370 | 71,245 | 15,859 |  |  |  |  |  |
Insurance | Professional lines | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 139,143 | 71,779 | 20,946 |  |  |  |  |  |  |
Insurance | Professional lines | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 81,986 | 20,091 |  |  |  |  |  |  |  |
Insurance | Professional lines | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 25,911 |  |  |  |  |  |  |  |  |
Insurance | Liability |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 648,147 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 50,617 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 738,722 |  |  |  |  |  |  |  |  |
Insurance | Liability | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 88,476 | 88,007 | 86,454 | 71,803 | 66,129 | 61,044 | 53,594 | 30,800 | 15,977 | 1,030
Insurance | Liability | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 67,114 | 62,150 | 60,261 | 54,996 | 46,074 | 38,377 | 20,190 | 10,540 | 2,761 |
Insurance | Liability | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 48,034 | 46,540 | 42,740 | 37,139 | 30,145 | 15,411 | 5,514 | 1,663 |  |
Insurance | Liability | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 71,982 | 66,963 | 60,004 | 42,049 | 33,319 | 23,280 | 2,359 |  |  |
Insurance | Liability | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 93,574 | 84,374 | 71,595 | 49,836 | 18,640 | 1,414 |  |  |  |
Insurance | Liability | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 120,216 | 92,664 | 39,637 | 22,392 | 5,438 |  |  |  |  |
Insurance | Liability | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 56,446 | 36,385 | 23,280 | 6,319 |  |  |  |  |  |
Insurance | Liability | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 59,356 | 29,564 | 5,439 |  |  |  |  |  |  |
Insurance | Liability | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 35,612 | 9,027 |  |  |  |  |  |  |  |
Insurance | Liability | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 7,337 |  |  |  |  |  |  |  |  |
Reinsurance |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 5,328,106 |  |  |  |  |  |  |  |  |
Reinsurance | Property and other |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 5,596,838 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 14,757 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 1,644,046 |  |  |  |  |  |  |  |  |
Reinsurance | Property and other | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 546,691 | 542,590 | 540,312 | 534,590 | 509,769 | 480,734 | 434,908 | 404,287 | 311,052 | 116,132
Reinsurance | Property and other | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 1,019,917 | 1,013,858 | 1,011,283 | 996,481 | 923,166 | 893,746 | 794,575 | 587,047 | 251,855 |
Reinsurance | Property and other | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 428,152 | 415,634 | 413,594 | 403,926 | 389,373 | 366,968 | 294,298 | 122,823 |  |
Reinsurance | Property and other | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 483,105 | 482,480 | 481,066 | 471,380 | 441,138 | 324,839 | 107,628 |  |  |
Reinsurance | Property and other | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 463,342 | 458,350 | 452,193 | 434,769 | 352,883 | 102,356 |  |  |  |
Reinsurance | Property and other | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 413,477 | 400,980 | 368,698 | 265,896 | 71,477 |  |  |  |  |
Reinsurance | Property and other | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 563,781 | 520,779 | 376,920 | 128,126 |  |  |  |  |  |
Reinsurance | Property and other | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 868,458 | 723,826 | 252,360 |  |  |  |  |  |  |
Reinsurance | Property and other | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 648,622 | 195,707 |  |  |  |  |  |  |  |
Reinsurance | Property and other | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 161,293 |  |  |  |  |  |  |  |  |
Reinsurance | Professional lines |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 945,996 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 52,321 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 969,167 |  |  |  |  |  |  |  |  |
Reinsurance | Professional lines | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 142,994 | 138,047 | 130,610 | 123,981 | 107,363 | 76,798 | 52,138 | 31,243 | 12,026 | 1,757
Reinsurance | Professional lines | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 136,492 | 130,059 | 119,767 | 103,052 | 84,845 | 57,230 | 30,272 | 11,822 | 1,510 |
Reinsurance | Professional lines | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 145,866 | 131,853 | 107,224 | 85,972 | 53,629 | 29,622 | 10,392 | 778 |  |
Reinsurance | Professional lines | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 123,282 | 104,904 | 81,630 | 64,958 | 30,491 | 12,073 | 1,064 |  |  |
Reinsurance | Professional lines | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 147,194 | 109,239 | 74,577 | 48,854 | 13,073 | 2,019 |  |  |  |
Reinsurance | Professional lines | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 112,042 | 79,296 | 41,539 | 13,505 | 3,134 |  |  |  |  |
Reinsurance | Professional lines | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 95,283 | 52,617 | 20,534 | 1,768 |  |  |  |  |  |
Reinsurance | Professional lines | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 39,915 | 14,921 | 2,813 |  |  |  |  |  |  |
Reinsurance | Professional lines | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 2,593 | 271 |  |  |  |  |  |  |  |
Reinsurance | Professional lines | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 335 |  |  |  |  |  |  |  |  |
Reinsurance | Liability |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 989,389 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 80,768 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 1,228,290 |  |  |  |  |  |  |  |  |
Reinsurance | Liability | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 130,566 | 128,386 | 119,678 | 108,748 | 97,430 | 83,792 | 62,287 | 46,199 | 17,652 | 2,479
Reinsurance | Liability | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 141,483 | 135,627 | 123,403 | 112,347 | 92,477 | 70,083 | 40,009 | 21,291 | 5,197 |
Reinsurance | Liability | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 125,979 | 115,618 | 101,164 | 78,235 | 58,777 | 28,384 | 12,800 | 3,541 |  |
Reinsurance | Liability | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 113,127 | 102,593 | 88,262 | 69,055 | 52,328 | 22,235 | 5,971 |  |  |
Reinsurance | Liability | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 109,974 | 89,412 | 70,138 | 48,420 | 28,661 | 7,083 |  |  |  |
Reinsurance | Liability | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 108,961 | 80,865 | 54,517 | 27,455 | 7,270 |  |  |  |  |
Reinsurance | Liability | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 111,870 | 69,558 | 37,703 | 11,874 |  |  |  |  |  |
Reinsurance | Liability | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 78,477 | 42,147 | 12,438 |  |  |  |  |  |  |
Reinsurance | Liability | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 49,795 | 19,303 |  |  |  |  |  |  |  |
Reinsurance | Liability | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 19,157 |  |  |  |  |  |  |  |  |
Reinsurance | Credit and surety |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 886,173 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 16,847 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 256,999 |  |  |  |  |  |  |  |  |
Reinsurance | Credit and surety | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 65,781 | 65,346 | 65,024 | 64,020 | 62,585 | 61,466 | 59,804 | 59,074 | 48,274 | 28,190
Reinsurance | Credit and surety | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 88,615 | 87,799 | 86,419 | 84,106 | 81,930 | 77,392 | 69,851 | 53,392 | 22,411 |
Reinsurance | Credit and surety | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 113,402 | 111,441 | 110,150 | 108,391 | 104,876 | 99,046 | 85,228 | 49,482 |  |
Reinsurance | Credit and surety | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 112,520 | 107,555 | 105,692 | 98,039 | 91,486 | 76,743 | 32,399 |  |  |
Reinsurance | Credit and surety | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 107,082 | 102,670 | 95,079 | 85,984 | 61,076 | 35,552 |  |  |  |
Reinsurance | Credit and surety | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 118,670 | 116,756 | 99,774 | 81,685 | 32,907 |  |  |  |  |
Reinsurance | Credit and surety | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 101,822 | 92,187 | 73,201 | 42,028 |  |  |  |  |  |
Reinsurance | Credit and surety | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 90,495 | 73,944 | 37,295 |  |  |  |  |  |  |
Reinsurance | Credit and surety | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 68,505 | 38,990 |  |  |  |  |  |  |  |
Reinsurance | Credit and surety | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 19,281 |  |  |  |  |  |  |  |  |
Reinsurance | Motor |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 1,146,305 |  |  |  |  |  |  |  |  |
All outstanding liabilities before 2010, net of reinsurance | 193,345 |  |  |  |  |  |  |  |  |
Liabilities for claims and claim adjustment expenses, net of reinsurance | 1,229,604 |  |  |  |  |  |  |  |  |
Reinsurance | Motor | Accident Year 2010 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 37,041 | 34,839 | 33,769 | 32,717 | 29,429 | 25,153 | 21,713 | 18,149 | 12,601 | $ 7,201
Reinsurance | Motor | Accident Year 2011 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 94,155 | 92,201 | 91,165 | 86,466 | 80,349 | 73,562 | 62,861 | 47,991 | $ 23,943 |
Reinsurance | Motor | Accident Year 2012 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 93,194 | 91,982 | 89,646 | 85,488 | 78,880 | 68,970 | 53,959 | $ 29,381 |  |
Reinsurance | Motor | Accident Year 2013 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 93,234 | 90,165 | 84,512 | 78,744 | 68,502 | 54,274 | $ 34,133 |  |  |
Reinsurance | Motor | Accident Year 2014 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 124,157 | 114,300 | 103,909 | 95,563 | 75,543 | $ 43,628 |  |  |  |
Reinsurance | Motor | Accident Year 2015 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 149,813 | 133,528 | 115,903 | 95,172 | $ 58,231 |  |  |  |  |
Reinsurance | Motor | Accident Year 2016 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 150,004 | 131,606 | 106,934 | $ 61,321 |  |  |  |  |  |
Reinsurance | Motor | Accident Year 2017 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 168,855 | 137,217 | $ 72,859 |  |  |  |  |  |  |
Reinsurance | Motor | Accident Year 2018 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | 145,561 | $ 84,564 |  |  |  |  |  |  |  |
Reinsurance | Motor | Accident Year 2019 |  |  |  |  |  |  |  |  |  |
Claims Development [Line Items] |  |  |  |  |  |  |  |  |  |
Cumulative paid claims and allocated claim adjustment expenses, net of reinsurance | $ 90,291 |  |  |  |  |  |  |  |  |

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