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Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Incurred claim and claim adjustment expenses related to current year | $ 6,330 | $ 5,667 | $ 5,181
Incurred claim and claim adjustment expenses related to prior years | 42 | 48 | (32)
Consolidated Property and Casualty Insurance Entity |  |  |
Deferred acquisition costs |  | 896 |
Reserves for unpaid claim and claim adjustment expenses | 24,976 | 23,304 |
Discount deducted from claim and claim adjustment expense reserves above (based on interest rates ranging from 3.5% to 6.6%) | 615 | 647 |
Unearned premiums | 7,346 | 6,933 |
Net written premiums | 10,605 | 9,892 | 9,128
Net earned premiums | 10,211 | 9,480 | 8,667
Net investment income | 2,396 | 2,163 | 1,751
Incurred claim and claim adjustment expenses related to current year |  | 5,667 | 5,181
Incurred claim and claim adjustment expenses related to prior years |  | 48 | (32)
Amortization of deferred acquisition costs | 1,798 | 1,644 | 1,490
Paid claim and claim adjustment expenses | $ 5,189 | $ 4,601 | $ 4,302
Consolidated Property and Casualty Insurance Entity | Minimum |  |  |
Supplemental Information Parenthetical |  |  |
SEC Schedule, 12-18, supplemental information, property-casualty insurance underwriters, interest rate at which discount computed | 3.50% | 3.50% | 3.50%
Consolidated Property and Casualty Insurance Entity | Maximum |  |  |
Supplemental Information Parenthetical |  |  |
SEC Schedule, 12-18, supplemental information, property-casualty insurance underwriters, interest rate at which discount computed | 6.60% | 6.60% | 6.60%

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- Definition Amount of amortization expense on deferred policy acquisition cost for property-casualty insurance underwriter. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18(Column I)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477965/944-235-S99-3 + Details
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- Definition Amount, after effects of reinsurance, of expense for claims incurred in the current reporting period and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-3 + Details
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- Definition Amount of deferred policy acquisition cost related to property-casualty insurance policy written. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477965/944-235-S99-3 + Details
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- Definition Amount of discount deducted from reserve for unpaid claim and claim adjustment expense by property-casualty insurance underwriter. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-18(Column D)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477965/944-235-S99-3 + Details
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