v2.4.0.8

INVESTMENTS (TABLES) | 6 Months Ended
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Jun. 30, 2013
Investments, Debt and Equity Securities [Abstract] |
AMORTIZED COST/COST AND FAIR VALUES OF FIXED MATURITIES AND EQUITIES [Table Text Block] |
|  | Amortized Cost or Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Fair Value |  | Non-credit OTTI in AOCI(5) |
| At June 30, 2013 |  |  |  |  |  |  |  |  |  |
| Fixed maturities |  |  |  |  |  |  |  |  |  |
| U.S. government and agency | $ | 1,369,338 |  |  | $ | 1,944 |  |  | $ | (32,468 | ) |  | $ | 1,338,814 |  |  | $ | — |  |
| Non-U.S. government | 1,212,124 |  |  | 7,444 |  |  | (42,619 | ) |  | 1,176,949 |  |  | — |  |
| Corporate debt | 3,458,874 |  |  | 65,487 |  |  | (44,445 | ) |  | 3,479,916 |  |  | — |  |
| Agency RMBS(1) | 2,353,080 |  |  | 23,441 |  |  | (42,897 | ) |  | 2,333,624 |  |  | — |  |
| CMBS(2) | 769,422 |  |  | 11,964 |  |  | (6,736 | ) |  | 774,650 |  |  | — |  |
| Non-Agency RMBS | 87,243 |  |  | 2,395 |  |  | (772 | ) |  | 88,866 |  |  | (818 | ) |
| ABS(3) | 912,073 |  |  | 6,150 |  |  | (6,542 | ) |  | 911,681 |  |  | — |  |
| Municipals(4) | 1,525,233 |  |  | 32,365 |  |  | (17,186 | ) |  | 1,540,412 |  |  | — |  |
| Total fixed maturities | $ | 11,687,387 |  |  | $ | 151,190 |  |  | $ | (193,665 | ) |  | $ | 11,644,912 |  |  | $ | (818 | ) |
| Equity securities |  |  |  |  |  |  |  |  |  |
| Common stocks | $ | 334,809 |  |  | $ | 63,721 |  |  | $ | (8,350 | ) |  | $ | 390,180 |  |  |  |
| Exchange-traded funds | 105,396 |  |  | 13,840 |  |  | — |  |  | 119,236 |  |  |  |
| Non-U.S. bond mutual funds | 106,326 |  |  | 3,053 |  |  | — |  |  | 109,379 |  |  |  |
| Total equity securities | $ | 546,531 |  |  | $ | 80,614 |  |  | $ | (8,350 | ) |  | $ | 618,795 |  |  |  |
| At December 31, 2012 |  |  |  |  |  |  |  |  |  |
| Fixed maturities |  |  |  |  |  |  |  |  |  |
| U.S. government and agency | $ | 1,413,520 |  |  | $ | 9,484 |  |  | $ | (119 | ) |  | $ | 1,422,885 |  |  | $ | — |  |
| Non-U.S. government | 1,076,501 |  |  | 30,276 |  |  | (2,201 | ) |  | 1,104,576 |  |  | — |  |
| Corporate debt | 3,746,616 |  |  | 135,658 |  |  | (5,892 | ) |  | 3,876,382 |  |  | — |  |
| Agency RMBS | 2,594,180 |  |  | 67,398 |  |  | (1,670 | ) |  | 2,659,908 |  |  | — |  |
| CMBS | 814,211 |  |  | 25,999 |  |  | (126 | ) |  | 840,084 |  |  | — |  |
| Non-Agency RMBS | 93,266 |  |  | 2,503 |  |  | (570 | ) |  | 95,199 |  |  | (884 | ) |
| ABS | 639,614 |  |  | 10,774 |  |  | (7,182 | ) |  | 643,206 |  |  | — |  |
| Municipals | 1,227,764 |  |  | 58,770 |  |  | (725 | ) |  | 1,285,809 |  |  | — |  |
| Total fixed maturities | $ | 11,605,672 |  |  | $ | 340,862 |  |  | $ | (18,485 | ) |  | $ | 11,928,049 |  |  | $ | (884 | ) |
| Equity securities |  |  |  |  |  |  |  |  |  |
| Common stocks | $ | 398,975 |  |  | $ | 51,821 |  |  | $ | (7,398 | ) |  | $ | 443,398 |  |  |  |
| Exchange-traded funds | 109,434 |  |  | 9,727 |  |  | — |  |  | 119,161 |  |  |  |
| Non-U.S. bond mutual funds | 99,897 |  |  | 4,092 |  |  | — |  |  | 103,989 |  |  |  |
| Total equity securities | $ | 608,306 |  |  | $ | 65,640 |  |  | $ | (7,398 | ) |  | $ | 666,548 |  |  |  |
(1) | Residential mortgage-backed securities (RMBS) originated by U.S. agencies.
(2) | Commercial mortgage-backed securities (CMBS).
(3) | Asset-backed securities (ABS) include debt tranched securities collateralized primarily by auto loans, student loans, credit cards, and other asset types. This asset class also includes collateralized loan obligations (CLOs) and collateralized debt obligations (CDOs).
(4) | Municipals include bonds issued by states, municipalities and political subdivisions.
(5) | Represents the non-credit component of the other-than-temporary impairment (OTTI) losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the impairment measurement date.
CONTRACTUAL MATURITIES OF FIXED MATURITIES [Table Text Block] |
|  | Amortized Cost |  | Fair Value |  | % of Total Fair Value |
| At June 30, 2013 |  |  |  |  |  |
| Maturity |  |  |  |  |  |
| Due in one year or less | $ | 642,706 |  |  | $ | 644,440 |  |  | 5.5 | % |
| Due after one year through five years | 4,720,844 |  |  | 4,737,031 |  |  | 40.7 | % |
| Due after five years through ten years | 2,099,552 |  |  | 2,053,073 |  |  | 17.6 | % |
| Due after ten years | 102,467 |  |  | 101,547 |  |  | 0.9 | % |
|  | 7,565,569 |  |  | 7,536,091 |  |  | 64.7 | % |
| Agency RMBS | 2,353,080 |  |  | 2,333,624 |  |  | 20.0 | % |
| CMBS | 769,422 |  |  | 774,650 |  |  | 6.7 | % |
| Non-Agency RMBS | 87,243 |  |  | 88,866 |  |  | 0.8 | % |
| ABS | 912,073 |  |  | 911,681 |  |  | 7.8 | % |
| Total | $ | 11,687,387 |  |  | $ | 11,644,912 |  |  | 100.0 | % |
| At December 31, 2012 |  |  |  |  |  |
| Maturity |  |  |  |  |  |
| Due in one year or less | $ | 651,111 |  |  | $ | 657,045 |  |  | 5.5 | % |
| Due after one year through five years | 4,880,039 |  |  | 4,989,151 |  |  | 41.8 | % |
| Due after five years through ten years | 1,847,295 |  |  | 1,951,569 |  |  | 16.4 | % |
| Due after ten years | 85,956 |  |  | 91,887 |  |  | 0.8 | % |
|  | 7,464,401 |  |  | 7,689,652 |  |  | 64.5 | % |
| Agency RMBS | 2,594,180 |  |  | 2,659,908 |  |  | 22.3 | % |
| CMBS | 814,211 |  |  | 840,084 |  |  | 7.0 | % |
| Non-Agency RMBS | 93,266 |  |  | 95,199 |  |  | 0.8 | % |
| ABS | 639,614 |  |  | 643,206 |  |  | 5.4 | % |
| Total | $ | 11,605,672 |  |  | $ | 11,928,049 |  |  | 100.0 | % |
FIXED MATURITIES AND EQUITIES IN AN UNREALIZED LOSS POSITION [Table Text Block] |
|  | 12 months or greater |  | Less than 12 months |  | Total |
|  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |
| At June 30, 2013 |  |  |  |  |  |  |  |  |  |  |  |
| Fixed maturities |  |  |  |  |  |  |  |  |  |  |  |
| U.S. government and agency | $ | — |  |  | $ | — |  |  | $ | 973,867 |  |  | $ | (32,468 | ) |  | $ | 973,867 |  |  | $ | (32,468 | ) |
| Non-U.S. government | 16,715 |  |  | (813 | ) |  | 823,750 |  |  | (41,806 | ) |  | 840,465 |  |  | (42,619 | ) |
| Corporate debt | 40,633 |  |  | (2,016 | ) |  | 1,527,022 |  |  | (42,429 | ) |  | 1,567,655 |  |  | (44,445 | ) |
| Agency RMBS | 295 |  |  | (3 | ) |  | 1,434,587 |  |  | (42,894 | ) |  | 1,434,882 |  |  | (42,897 | ) |
| CMBS | 71 |  |  | — |  |  | 354,550 |  |  | (6,736 | ) |  | 354,621 |  |  | (6,736 | ) |
| Non-Agency RMBS | 4,477 |  |  | (404 | ) |  | 19,068 |  |  | (368 | ) |  | 23,545 |  |  | (772 | ) |
| ABS | 66,137 |  |  | (4,559 | ) |  | 268,462 |  |  | (1,983 | ) |  | 334,599 |  |  | (6,542 | ) |
| Municipals | 1,323 |  |  | (45 | ) |  | 645,982 |  |  | (17,141 | ) |  | 647,305 |  |  | (17,186 | ) |
| Total fixed maturities | $ | 129,651 |  |  | $ | (7,840 | ) |  | $ | 6,047,288 |  |  | $ | (185,825 | ) |  | $ | 6,176,939 |  |  | $ | (193,665 | ) |
| Equity securities |  |  |  |  |  |  |  |  |  |  |  |
| Common stocks | $ | 9,138 |  |  | $ | (1,202 | ) |  | $ | 74,569 |  |  | $ | (7,148 | ) |  | $ | 83,707 |  |  | $ | (8,350 | ) |
| Total equity securities | $ | 9,138 |  |  | $ | (1,202 | ) |  | $ | 74,569 |  |  | $ | (7,148 | ) |  | $ | 83,707 |  |  | $ | (8,350 | ) |
| At December 31, 2012 |  |  |  |  |  |  |  |  |  |  |  |
| Fixed maturities |  |  |  |  |  |  |  |  |  |  |  |
| U.S. government and agency | $ | — |  |  | $ | — |  |  | $ | 119,730 |  |  | $ | (119 | ) |  | $ | 119,730 |  |  | $ | (119 | ) |
| Non-U.S. government | 44,568 |  |  | (1,453 | ) |  | 153,134 |  |  | (748 | ) |  | 197,702 |  |  | (2,201 | ) |
| Corporate debt | 95,511 |  |  | (2,947 | ) |  | 451,651 |  |  | (2,945 | ) |  | 547,162 |  |  | (5,892 | ) |
| Agency RMBS | 9,557 |  |  | (148 | ) |  | 521,400 |  |  | (1,522 | ) |  | 530,957 |  |  | (1,670 | ) |
| CMBS | 1,749 |  |  | (16 | ) |  | 69,615 |  |  | (110 | ) |  | 71,364 |  |  | (126 | ) |
| Non-Agency RMBS | 11,026 |  |  | (537 | ) |  | 115 |  |  | (33 | ) |  | 11,141 |  |  | (570 | ) |
| ABS | 99,514 |  |  | (7,034 | ) |  | 39,296 |  |  | (148 | ) |  | 138,810 |  |  | (7,182 | ) |
| Municipals | 6,386 |  |  | (270 | ) |  | 77,766 |  |  | (455 | ) |  | 84,152 |  |  | (725 | ) |
| Total fixed maturities | $ | 268,311 |  |  | $ | (12,405 | ) |  | $ | 1,432,707 |  |  | $ | (6,080 | ) |  | $ | 1,701,018 |  |  | $ | (18,485 | ) |
| Equity securities |  |  |  |  |  |  |  |  |  |  |  |
| Common stocks | $ | 11,554 |  |  | $ | (1,793 | ) |  | $ | 95,697 |  |  | $ | (5,605 | ) |  | $ | 107,251 |  |  | $ | (7,398 | ) |
| Total equity securities | $ | 11,554 |  |  | $ | (1,793 | ) |  | $ | 95,697 |  |  | $ | (5,605 | ) |  | $ | 107,251 |  |  | $ | (7,398 | ) |
PORTFOLIO OF OTHER INVESTMENTS [Table Text Block] |
|  | Fair Value |  | Redemption Frequency (if currently eligible) |  | Redemption Notice Period |
| At June 30, 2013 |  |  |  |  |  |  |  |  |  |
| Long/short equity funds | $ | 397,917 |  |  | 41 | % |  | Monthly, Quarterly, Semi-annually |  | 30-60 days |
| Multi-strategy funds | 264,688 |  |  | 28 | % |  | Quarterly, Semi-annually |  | 60-95 days |
| Event-driven funds | 192,185 |  |  | 20 | % |  | Quarterly, Annually |  | 45-95 days |
| Leveraged bank loan funds | 50,249 |  |  | 5 | % |  | Quarterly |  | 65 days |
| Direct lending funds | 4,232 |  |  | — | % |  | n/a |  | n/a |
| CLO - Equities | 53,044 |  |  | 6 | % |  | n/a |  | n/a |
| Total other investments | $ | 962,315 |  |  | 100 | % |  |  |  |  |
| At December 31, 2012 |  |  |  |  |  |  |  |  |  |
| Long/short equity funds | $ | 302,680 |  |  | 36 | % |  | Monthly, Quarterly, Semi-annually |  | 30-60 days |
| Multi-strategy funds | 244,075 |  |  | 29 | % |  | Quarterly, Semi-annually |  | 60-95 days |
| Event-driven funds | 171,479 |  |  | 20 | % |  | Quarterly, Annually |  | 45-95 days |
| Leveraged bank loan funds | 62,768 |  |  | 8 | % |  | Quarterly |  | 65 days |
| Direct lending funds | — |  |  | — | % |  | n/a |  | n/a |
| CLO - Equities | 62,435 |  |  | 7 | % |  | n/a |  | n/a |
| Total other investments | $ | 843,437 |  |  | 100 | % |  |  |  |  |
n/a - not applicable
NET INVESTMENT INCOME [Table Text Block] |
|  | Three months ended June 30, |  | Six months ended June 30, |
|  | 2013 |  | 2012 |  | 2013 |  | 2012 |
| Fixed maturities | $ | 74,503 |  |  | $ | 76,544 |  |  | $ | 144,185 |  |  | $ | 156,181 |  |
| Other investments | 11,848 |  |  | (2,304 | ) |  | 55,279 |  |  | 38,116 |  |
| Equity securities | 3,134 |  |  | 5,071 |  |  | 4,548 |  |  | 6,180 |  |
| Cash and cash equivalents | 1,265 |  |  | 1,663 |  |  | 2,533 |  |  | 3,271 |  |
| Short-term investments | 397 |  |  | 33 |  |  | 929 |  |  | 188 |  |
| Gross investment income | 91,147 |  |  | 81,007 |  |  | 207,474 |  |  | 203,936 |  |
| Investment expenses | (8,035 | ) |  | (6,558 | ) |  | (15,455 | ) |  | (13,464 | ) |
| Net investment income | $ | 83,112 |  |  | $ | 74,449 |  |  | $ | 192,019 |  |  | $ | 190,472 |  |
NET REALIZED INVESTMENT GAINS (LOSSES) [Table Text Block] |
|  | Three months ended June 30, |  | Six months ended June 30, |
|  | 2013 |  | 2012 |  | 2013 |  | 2012 |
| Gross realized gains | $ | 44,487 |  |  | $ | 72,354 |  |  | $ | 103,268 |  |  | $ | 140,600 |  |
| Gross realized losses | (33,253 | ) |  | (40,466 | ) |  | (53,822 | ) |  | (86,377 | ) |
| Net OTTI recognized in earnings | (5,127 | ) |  | (13,739 | ) |  | (6,025 | ) |  | (17,648 | ) |
| Net realized gains on fixed maturities and equity securities | 6,107 |  |  | 18,149 |  |  | 43,421 |  |  | 36,575 |  |
| Change in fair value of investment derivatives(1) | 10,128 |  |  | 6,697 |  |  | 17,292 |  |  | 815 |  |
| Fair value hedges(1) | — |  |  | 5,559 |  |  | — |  |  | 7,506 |  |
| Net realized investment gains | $ | 16,235 |  |  | $ | 30,405 |  |  | $ | 60,713 |  |  | $ | 44,896 |  |
(1) Refer to Note 5 – Derivative Instruments
OTTI RECOGNIZED IN EARNINGS BY ASSET CLASS [Table Text Block] |
|  | Three months ended June 30, |  | Six months ended June 30, |
|  | 2013 |  | 2012 |  | 2013 |  | 2012 |
| Fixed maturities: |  |  |  |  |  |  |  |
| Non-U.S. government | $ | 25 |  |  | $ | 999 |  |  | $ | 25 |  |  | $ | 999 |  |
| Corporate debt | 3,535 |  |  | 453 |  |  | 3,950 |  |  | 558 |  |
| Non-Agency RMBS | — |  |  | 911 |  |  | — |  |  | 2,119 |  |
| ABS | — |  |  | 298 |  |  | 129 |  |  | 478 |  |
|  | 3,560 |  |  | 2,661 |  |  | 4,104 |  |  | 4,154 |  |
| Equities |  |  |  |  |  |  |  |
| Common stocks | 1,046 |  |  | 2,075 |  |  | 1,400 |  |  | 4,491 |  |
| Exchange-traded funds | 521 |  |  | 9,003 |  |  | 521 |  |  | 9,003 |  |
|  | 1,567 |  |  | 11,078 |  |  | 1,921 |  |  | 13,494 |  |
| Total OTTI recognized in earnings | $ | 5,127 |  |  | $ | 13,739 |  |  | $ | 6,025 |  |  | $ | 17,648 |  |
ROLL FORWARD OF CREDIT LOSSES FOR WHICH A PORTION OF OTTI RECOGNIZED IN AOCI [Table Text Block] |
|  | Three months ended June 30, |  | Six months ended June 30, |
|  | 2013 |  | 2012 |  | 2013 |  | 2012 |
| Balance at beginning of period | $ | 1,712 |  |  | $ | 2,047 |  |  | $ | 1,809 |  |  | $ | 2,061 |  |
| Credit impairments recognized on securities not previously impaired | — |  |  | — |  |  | — |  |  | — |  |
| Additional credit impairments recognized on securities previously impaired | — |  |  | — |  |  | — |  |  | — |  |
| Change in timing of future cash flows on securities previously impaired | — |  |  | — |  |  | — |  |  | — |  |
| Intent to sell of securities previously impaired | — |  |  | — |  |  | — |  |  | — |  |
| Securities sold/redeemed/matured | (13 | ) |  | (98 | ) |  | (110 | ) |  | (112 | ) |
| Balance at end of period | $ | 1,699 |  |  | $ | 1,949 |  |  | $ | 1,699 |  |  | $ | 1,949 |  |

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