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v3.20.4

Segment Information (Operations By Segment) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | $ 33,820 | $ 32,275 | $ 30,579
Net premiums earned |  | 33,117 | 31,290 | 30,064
Losses and loss expenses |  | 21,710 | 18,730 | 18,067
Policy benefits |  | 784 | 740 | 590
Policy Acquisition Costs |  | 6,547 | 6,153 | 5,912
Administrative expenses |  | 2,979 | 3,030 | 2,886
Underwriting income (loss) |  | 1,097 | 2,637 | 2,609
Net Investment Income |  | 3,375 | 3,426 | 3,305
Other (Income) Expense |  | (994) | (596) | (434)
Amortization of Purchased Intangibles |  | 290 | 305 | 339
Segment Underwriting Income Loss and Net Investment Income Loss |  | 5,176 | 6,354 | 6,009
Interest expense |  | 516 | 552 | 641
Chubb integration expenses |  | 0 | 23 | 59
Income tax expense (benefit) |  | 629 | 795 | 695
Net income |  | 3,533 | 4,454 | 3,962
Derivative, Gain (Loss) on Derivative, Net |  | 228 | 585 | 330
Other (income) expense |  | (994) | (596) | (434)
(Gains) losses from fair value changes in separate account assets | [1] | 58 | 44 | (38)
Realized Investment Gains (Losses) |  | (498) | (530) | (652)
Interest Income (Expense), Net |  | 516 | 552 | 641
Segment Reconciling Items [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 0 | 0 | 0
Net premiums earned |  | 0 | 0 | 0
Losses and loss expenses |  | 1 | (8) | (3)
Policy benefits |  | 58 | 44 | (38)
Policy Acquisition Costs |  | 0 | 0 | 0
Administrative expenses |  | 0 | 0 | 0
Net Investment Income |  | (115) | (86) | (63)
Other (Income) Expense |  | (173) | (130) | (25)
Amortization of Purchased Intangibles |  | 0 | 0 | 0
Segment Underwriting Income Loss and Net Investment Income Loss |  | (1) | 8 | 3
Chubb integration expenses |  |  | 0 | 0
Income tax expense (benefit) |  | 0 | 0 | 0
Net income |  | 0 | 0 | 0
Realized Investment Gains (Losses) |  | 1 | (8) | (3)
Underwriting Income (Loss) |  | (59) | (36) | 41
Interest Income (Expense), Net |  | 0 | 0 | 0
North America Commercial P&C Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 14,474 | 13,375 | 12,485
Net premiums earned |  | 13,964 | 12,922 | 12,402
Losses and loss expenses |  | 10,129 | 8,206 | 8,000
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 1,942 | 1,831 | 1,829
Administrative expenses |  | 1,006 | 1,028 | 966
Underwriting income (loss) |  | 887 | 1,857 | 1,607
Net Investment Income |  | 2,061 | 2,109 | 2,061
Other (Income) Expense |  | 23 | 24 | 3
Amortization of Purchased Intangibles |  | 0 | 0 | 0
Segment Underwriting Income Loss and Net Investment Income Loss |  | 2,925 | 3,942 | 3,665
Segment Insurance North American Personal P&C [Member] [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 4,920 | 4,787 | 4,674
Net premiums earned |  | 4,866 | 4,694 | 4,593
Losses and loss expenses |  | 3,187 | 3,043 | 3,229
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 974 | 948 | 939
Administrative expenses |  | 270 | 286 | 269
Underwriting income (loss) |  | 435 | 417 | 156
Net Investment Income |  | 260 | 258 | 236
Other (Income) Expense |  | 5 | 3 | 1
Amortization of Purchased Intangibles |  | 11 | 12 | 13
Segment Underwriting Income Loss and Net Investment Income Loss |  | 679 | 660 | 378
North America Agricultural Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 1,846 | 1,810 | 1,577
Net premiums earned |  | 1,822 | 1,795 | 1,569
Losses and loss expenses |  | 1,544 | 1,616 | 1,114
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 123 | 84 | 79
Administrative expenses |  | 9 | 6 | (9)
Underwriting income (loss) |  | 146 | 89 | 385
Net Investment Income |  | 30 | 30 | 28
Other (Income) Expense |  | 1 | 1 | 2
Amortization of Purchased Intangibles |  | 27 | 28 | 28
Segment Underwriting Income Loss and Net Investment Income Loss |  | 148 | 90 | 383
Overseas General Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 9,335 | 9,262 | 8,902
Net premiums earned |  | 9,285 | 8,882 | 8,612
Losses and loss expenses |  | 5,255 | 4,606 | 4,429
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 2,568 | 2,501 | 2,346
Administrative expenses |  | 1,034 | 1,033 | 1,014
Underwriting income (loss) |  | 428 | 742 | 823
Net Investment Income |  | 534 | 588 | 622
Other (Income) Expense |  | 13 | 12 | 3
Amortization of Purchased Intangibles |  | 45 | 45 | 41
Segment Underwriting Income Loss and Net Investment Income Loss |  | 904 | 1,273 | 1,401
Segment Global Reinsurance [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 731 | 649 | 671
Net premiums earned |  | 698 | 654 | 670
Losses and loss expenses |  | 435 | 352 | 479
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 174 | 169 | 162
Administrative expenses |  | 37 | 35 | 41
Underwriting income (loss) |  | 52 | 98 | (12)
Net Investment Income |  | 307 | 279 | 289
Other (Income) Expense |  | 2 | 1 | 0
Amortization of Purchased Intangibles |  | 0 | 0 | 0
Segment Underwriting Income Loss and Net Investment Income Loss |  | 357 | 376 | 277
Life Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 2,514 | 2,392 | 2,270
Net premiums earned |  | 2,482 | 2,343 | 2,218
Losses and loss expenses |  | 724 | 757 | 766
Policy benefits |  | 726 | 696 | 628
Policy Acquisition Costs |  | 766 | 620 | 557
Administrative expenses |  | 320 | 323 | 310
Underwriting income (loss) |  | (54) | (53) | (43)
Net Investment Income |  | 385 | 373 | 341
Other (Income) Expense |  | (74) | (48) | (12)
Amortization of Purchased Intangibles |  | 4 | 2 | 2
Segment Underwriting Income Loss and Net Investment Income Loss |  | 401 | 366 | 308
Corporate and Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums written |  | 0 | 0 | 0
Net premiums earned |  | 0 | 0 | 0
Losses and loss expenses |  | 435 | 158 | 53
Policy benefits |  | 0 | 0 | 0
Policy Acquisition Costs |  | 0 | 0 | 0
Administrative expenses |  | 303 | 319 | 295
Underwriting income (loss) |  | (738) | (477) | (348)
Net Investment Income |  | (87) | (125) | (209)
Other (Income) Expense |  | (791) | (459) | (406)
Amortization of Purchased Intangibles |  | 203 | 218 | 255
Segment Underwriting Income Loss and Net Investment Income Loss |  | (237) | (361) | (406)
Interest expense |  | 516 | 552 | 641
Chubb integration expenses |  |  | 23 | 59
Income tax expense (benefit) |  | 629 | 795 | 695
Net income |  | (1,881) | (2,253) | (2,450)
Realized Investment Gains (Losses) |  | $ (499) | $ (522) | $ (649)
[1] | Related to gains (losses) from fair value changes in separate account assets that do not qualify for separate account reporting under GAAP.

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