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Business Segments (Income Statement Information) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Segment Reporting Information [Line Items] |  |  |
Net written premiums | $ 10,605 | $ 9,892 | $ 9,128
Operating revenues |  |  |
Net earned premiums | 10,211 | 9,480 | 8,667
Net investment income | 2,497 | 2,264 | 1,805
Non-insurance warranty revenue | 1,609 | 1,624 | 1,574
Other revenues | 34 | 30 | 32
Total operating revenues | 14,351 | 13,398 | 12,078
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 7,704 | 7,039 | 6,628
Policyholders’ dividends | 34 | 29 | 25
Amortization of deferred acquisition costs | 1,798 | 1,644 | 1,490
Non-insurance warranty expense | 1,547 | 1,544 | 1,471
Insurance related administrative expenses | 1,275 | 1,251 | 1,160
Interest expense | 133 | 127 | 112
Other expenses | 197 | 147 | 179
Total claims, benefits and expenses | 12,688 | 11,781 | 11,065
Income tax (expense) benefit on core income (loss) | (347) | (333) | (177)
Core income (loss) | 1,316 | 1,284 | 836
Net investment gains (losses) | (81) | (99) | (199)
Income tax (expense) benefit on net investment gains (losses) | 17 | 20 | 45
Net investment gains (losses), after tax | (64) | (79) | (154)
Pension settlement transaction gains (losses) | (371) | 0 | 0
Income tax (expense) benefit on pension settlement transaction gains (losses) | 78 |  |
Pension settlement transaction gains (losses), after tax | (293) |  |
Net income (loss) | 959 | 1,205 | 682
Operating Segments | Specialty |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | 3,445 | 3,329 | 3,306
Operating revenues |  |  |
Net earned premiums | 3,361 | 3,307 | 3,203
Net investment income | 626 | 558 | 431
Non-insurance warranty revenue | 1,609 | 1,624 | 1,574
Other revenues | 2 | 1 | 1
Total operating revenues | 5,598 | 5,490 | 5,209
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 2,001 | 1,923 | 1,839
Policyholders’ dividends | 9 | 8 | 6
Amortization of deferred acquisition costs | 740 | 686 | 656
Non-insurance warranty expense | 1,547 | 1,544 | 1,471
Insurance related administrative expenses | 362 | 373 | 336
Interest expense | 0 | 1 | 0
Other expenses | 55 | 52 | 51
Total claims, benefits and expenses | 4,714 | 4,587 | 4,359
Income tax (expense) benefit on core income (loss) | (190) | (195) | (182)
Core income (loss) | 694 | 708 | 668
Operating Segments | Commercial |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | 5,469 | 4,880 | 4,193
Operating revenues |  |  |
Net earned premiums | 5,158 | 4,547 | 3,923
Net investment income | 733 | 645 | 488
Non-insurance warranty revenue | 0 | 0 | 0
Other revenues | 29 | 29 | 30
Total operating revenues | 5,920 | 5,221 | 4,441
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 3,525 | 2,995 | 2,607
Policyholders’ dividends | 25 | 21 | 19
Amortization of deferred acquisition costs | 824 | 729 | 634
Non-insurance warranty expense | 0 | 0 | 0
Insurance related administrative expenses | 613 | 620 | 557
Interest expense | 0 | 0 | 0
Other expenses | 43 | 30 | 36
Total claims, benefits and expenses | 5,030 | 4,395 | 3,853
Income tax (expense) benefit on core income (loss) | (188) | (174) | (122)
Core income (loss) | 702 | 652 | 466
Operating Segments | International |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | 1,262 | 1,237 | 1,164
Operating revenues |  |  |
Net earned premiums | 1,256 | 1,176 | 1,070
Net investment income | 131 | 103 | 63
Non-insurance warranty revenue | 0 | 0 | 0
Other revenues | 0 | 0 | 1
Total operating revenues | 1,387 | 1,279 | 1,134
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 764 | 722 | 637
Policyholders’ dividends | 0 | 0 | 0
Amortization of deferred acquisition costs | 234 | 229 | 200
Non-insurance warranty expense | 0 | 0 | 0
Insurance related administrative expenses | 182 | 139 | 146
Interest expense | 0 | 0 | 0
Other expenses | 10 | (4) | 26
Total claims, benefits and expenses | 1,190 | 1,086 | 1,009
Income tax (expense) benefit on core income (loss) | (44) | (48) | (19)
Core income (loss) | 153 | 145 | 106
Operating Segments | Life & Group |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | 430 | 447 | 467
Operating revenues |  |  |
Net earned premiums | 437 | 451 | 473
Net investment income | 940 | 896 | 804
Non-insurance warranty revenue | 0 | 0 | 0
Other revenues | 0 | (1) | (1)
Total operating revenues | 1,377 | 1,346 | 1,276
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 1,308 | 1,317 | 1,469
Policyholders’ dividends | 0 | 0 | 0
Amortization of deferred acquisition costs | 0 | 0 | 0
Non-insurance warranty expense | 0 | 0 | 0
Insurance related administrative expenses | 119 | 118 | 118
Interest expense | 0 | 0 | 0
Other expenses | 2 | 1 | 9
Total claims, benefits and expenses | 1,429 | 1,436 | 1,596
Income tax (expense) benefit on core income (loss) | 29 | 42 | 99
Core income (loss) | (23) | (48) | (221)
Operating Segments | Corporate & Other |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | 0 | 0 | (1)
Operating revenues |  |  |
Net earned premiums | 0 | 0 | (1)
Net investment income | 67 | 62 | 19
Non-insurance warranty revenue | 0 | 0 | 0
Other revenues | 13 | 11 | 6
Total operating revenues | 80 | 73 | 24
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 106 | 82 | 76
Policyholders’ dividends | 0 | 0 | 0
Amortization of deferred acquisition costs | 0 | 0 | 0
Non-insurance warranty expense | 0 | 0 | 0
Insurance related administrative expenses | 0 | 2 | 4
Interest expense | 133 | 126 | 112
Other expenses | 97 | 78 | 62
Total claims, benefits and expenses | 336 | 288 | 254
Income tax (expense) benefit on core income (loss) | 46 | 42 | 47
Core income (loss) | (210) | (173) | (183)
Eliminations |  |  |
Segment Reporting Information [Line Items] |  |  |
Net written premiums | (1) | (1) | (1)
Operating revenues |  |  |
Net earned premiums | (1) | (1) | (1)
Net investment income | 0 | 0 | 0
Non-insurance warranty revenue | 0 | 0 | 0
Other revenues | (10) | (10) | (5)
Total operating revenues | (11) | (11) | (6)
Claims, Benefits and Expenses |  |  |
Net incurred claims and benefits | 0 | 0 | 0
Policyholders’ dividends | 0 | 0 | 0
Amortization of deferred acquisition costs | 0 | 0 | 0
Non-insurance warranty expense | 0 | 0 | 0
Insurance related administrative expenses | (1) | (1) | (1)
Interest expense | 0 | 0 | 0
Other expenses | (10) | (10) | (5)
Total claims, benefits and expenses | (11) | (11) | (6)
Income tax (expense) benefit on core income (loss) | 0 | 0 | 0
Core income (loss) | $ 0 | $ 0 | $ 0

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