| UNDERWRITING RESULTS OF REPORTABLE SEGMENTS [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | At and year ended December 31, 2013 | Insurance | | Reinsurance | | Total | | | | | | | | | | | Gross premiums written | $ | 2,559,138 |
| | $ | 2,137,903 |
| | $ | 4,697,041 |
| | | Net premiums written | 1,813,538 |
| | 2,114,662 |
| | 3,928,200 |
| | | Net premiums earned | 1,722,762 |
| | 1,984,303 |
| | 3,707,065 |
| | | Other insurance related income | 2,436 |
| | 1,988 |
| | 4,424 |
| | | Net losses and loss expenses | (1,050,402 | ) | | (1,083,793 | ) | | (2,134,195 | ) | | | Acquisition costs | (242,363 | ) | | (421,828 | ) | | (664,191 | ) | | | General and administrative expenses | (347,684 | ) | | (137,450 | ) | | (485,134 | ) | | | Underwriting income | $ | 84,749 |
| | $ | 343,220 |
| | 427,969 |
| | | | | | | | | | | Corporate expenses | | | | | (90,256 | ) | | | Net investment income | | | | | 409,312 |
| | | Net realized investment gains | | | | | 75,564 |
| | | Foreign exchange losses | | | | | (26,143 | ) | | | Interest expense and financing costs | | | | | (61,979 | ) | | | Income before income taxes | | | | | $ | 734,467 |
| | | | | | | | | | | Net loss and loss expense ratio | 61.0 | % | | 54.6 | % | | 57.6 | % | | | Acquisition cost ratio | 14.1 | % | | 21.3 | % | | 17.9 | % | | | General and administrative expense ratio | 20.1 | % | | 6.9 | % | | 15.5 | % | | | Combined ratio | 95.2 | % | | 82.8 | % | | 91.0 | % | | | | | | | | | | | Goodwill and intangible assets | $ | 89,528 |
| | $ | — |
| | $ | 89,528 |
| | | | | | | | | |
| | | | | | | | | | | | | | | | | | | | | | | | At and year ended December 31, 2012 | Insurance | | Reinsurance | | Total | | | | | | | | | | | Gross premiums written | $ | 2,309,481 |
| | $ | 1,830,162 |
| | $ | 4,139,643 |
| | | Net premiums written | 1,522,245 |
| | 1,815,211 |
| | 3,337,456 |
| | | Net premiums earned | 1,558,058 |
| | 1,857,405 |
| | 3,415,463 |
| | | Other insurance related income | 2,676 |
| | — |
| | 2,676 |
| | | Net losses and loss expenses | (953,564 | ) | | (1,142,464 | ) | | (2,096,028 | ) | | | Acquisition costs | (226,859 | ) | | (400,794 | ) | | (627,653 | ) | | | General and administrative expenses | (314,834 | ) | | (116,487 | ) | | (431,321 | ) | | | Underwriting income | $ | 65,477 |
| | $ | 197,660 |
| | 263,137 |
| | | | | | | | | | | Corporate expenses | | | | | (129,660 | ) | | | Net investment income | | | | | 380,957 |
| | | Net realized investment gains | | | | | 127,469 |
| | | Foreign exchange losses | | | | | (29,512 | ) | | | Interest expense and financing costs | | | | | (61,863 | ) | | | Income before income taxes | | | | | $ | 550,528 |
| | | | | | | | | | | Net loss and loss expense ratio | 61.2 | % | | 61.5 | % | | 61.4 | % | | | Acquisition cost ratio | 14.6 | % | | 21.6 | % | | 18.4 | % | | | General and administrative expense ratio | 20.2 | % | | 6.3 | % | | 16.4 | % | | | Combined ratio | 96.0 | % | | 89.4 | % | | 96.2 | % | | | | | | | | | | | Goodwill and intangible assets | $ | 97,493 |
| | $ | — |
| | $ | 97,493 |
| | | | | | | | | |
| | | | | | | | | | | | | | | | | | | | | | | | At and year ended December 31, 2011 | Insurance | | Reinsurance | | Total | | | | | | | | | | | Gross premiums written | $ | 2,121,829 |
| | $ | 1,974,324 |
| | $ | 4,096,153 |
| | | Net premiums written | 1,466,134 |
| | 1,953,300 |
| | 3,419,434 |
| | | Net premiums earned | 1,429,687 |
| | 1,885,274 |
| | 3,314,961 |
| | | Other insurance related income | 2,396 |
| | — |
| | 2,396 |
| | | Net losses and loss expenses | (919,319 | ) | | (1,755,733 | ) | | (2,675,052 | ) | | | Acquisition costs | (199,583 | ) | | (387,886 | ) | | (587,469 | ) | | | General and administrative expenses | (278,147 | ) | | (103,915 | ) | | (382,062 | ) | | | Underwriting income (loss) | $ | 35,034 |
| | $ | (362,260 | ) | | (327,226 | ) | | | | | | | | | | | Corporate expenses | | | | | (77,089 | ) | | | Net investment income | | | | | 362,430 |
| | | Net realized investment gains | | | | | 121,439 |
| | | Foreign exchange gains | | | | | 44,582 |
| | | Interest expense and financing costs | | | | | (62,598 | ) | | | Income before income taxes | | | | | $ | 61,538 |
| | | | | | | | | | | Net loss and loss expense ratio | 64.3 | % | | 93.1 | % | | 80.7 | % | | | Acquisition cost ratio | 14.0 | % | | 20.6 | % | | 17.7 | % | | | General and administrative expense ratio | 19.4 | % | | 5.5 | % | | 13.9 | % | | | Combined ratio | 97.7 | % | | 119.2 | % | | 112.3 | % | | | | | | | | | | | Goodwill and intangible assets | $ | 99,590 |
| | $ | — |
| | $ | 99,590 |
| | | | | | | | | |
|
| NET PREMIUMS EARNED BY SEGMENT AND LINE OF BUSINESS [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | Year ended December 31, | 2013 | | 2012 | | 2011 | | | | | | | | | | | Insurance | | | | | | | | Property | $ | 462,364 |
| | $ | 408,943 |
| | $ | 385,291 |
| | | Marine | 179,057 |
| | 171,165 |
| | 152,123 |
| | | Terrorism | 39,298 |
| | 38,605 |
| | 35,213 |
| | | Aviation | 48,489 |
| | 60,363 |
| | 70,681 |
| | | Credit and political risk | 68,192 |
| | 87,103 |
| | 97,680 |
| | | Professional lines | 586,200 |
| | 563,500 |
| | 536,238 |
| | | Liability | 110,623 |
| | 86,873 |
| | 89,555 |
| | | Accident & health | 228,539 |
| | 141,506 |
| | 62,906 |
| | | Total Insurance | 1,722,762 |
| | 1,558,058 |
| | 1,429,687 |
| | | | | | | | | | | Reinsurance | | | | | | | | Catastrophe | 380,199 |
| | 375,088 |
| | 456,858 |
| | | Property | 350,970 |
| | 351,470 |
| | 356,022 |
| | | Professional lines | 304,754 |
| | 297,726 |
| | 281,025 |
| | | Credit and surety | 279,943 |
| | 277,185 |
| | 263,912 |
| | | Motor | 221,844 |
| | 237,006 |
| | 202,830 |
| | | Liability | 234,736 |
| | 220,874 |
| | 230,872 |
| | | Agriculture | 126,490 |
| | 17,116 |
| | 15,031 |
| | | Engineering | 66,243 |
| | 68,402 |
| | 65,727 |
| | | Other | 19,124 |
| | 12,538 |
| | 12,997 |
| | | Total Reinsurance | 1,984,303 |
| | 1,857,405 |
| | 1,885,274 |
| | | | | | | | | | | Total | $ | 3,707,065 |
| | $ | 3,415,463 |
| | $ | 3,314,961 |
| | | | | | | | | |
|