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Fair Value of Financial Instruments (Fair Value Hierarchy Table Presents The Company's Assets And Liabilities At Fair Value Not Recorded On The Company's Consolidated Balance Sheet) (Detail) - Value Disclosed At Fair Value Not Recorded At Fair Value [Member] - Fair Value Measurements Nonrecurring [Member] - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Carrying Reported Amount Fair Value Disclosure [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Other investments | $ 1 |  | $ 3 |
Total assets | 1 |  | 3 |
Long-term debt | 2,741 |  | 2,585 |
Medium-term notes | 403 | [1] | 455 | [2]
Investment agreements | 204 |  | 221 |
Total liabilities | 3,360 |  | 3,264 |
Gross liability (recoverable) | 540 |  | 522 |
Ceded recoverable (liability) | 18 |  | 16 |
Fair Value [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Other investments | 1 |  | 3 |
Total assets | 1 |  | 3 |
Long-term debt | 305 |  | 287 |
Medium-term notes | 217 |  | 291 |
Investment agreements | 217 |  | 243 |
Total liabilities | 751 |  | 824 |
Gross liability (recoverable) | 764 |  | 837 |
Ceded recoverable (liability) | 19 |  | 20 |
Fair Value [Member] | Fair Value Inputs Level 1 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Other investments | 0 |  | 0 |
Total assets | 0 |  | 0 |
Long-term debt | 0 |  | 0 |
Medium-term notes | 0 |  | 0 |
Investment agreements | 0 |  | 0 |
Total liabilities | 0 |  | 0 |
Gross liability (recoverable) | 0 |  | 0 |
Ceded recoverable (liability) | 0 |  | 0 |
Fair Value [Member] | Fair Value Inputs Level 2 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Other investments | 0 |  | 0 |
Total assets | 0 |  | 0 |
Long-term debt | 305 |  | 287 |
Medium-term notes | 0 |  | 0 |
Investment agreements | 0 |  | 0 |
Total liabilities | 305 |  | 287 |
Gross liability (recoverable) | 0 |  | 0 |
Ceded recoverable (liability) | 0 |  | 0 |
Fair Value [Member] | Fair Value Inputs Level 3 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Other investments | 1 |  | 3 |
Total assets | 1 |  | 3 |
Long-term debt | 0 |  | 0 |
Medium-term notes | 217 |  | 291 |
Investment agreements | 217 |  | 243 |
Total liabilities | 446 |  | 537 |
Gross liability (recoverable) | 764 |  | 837 |
Ceded recoverable (liability) | 19 |  | 20 |
Liabilities Of Consolidated Vies [Member] | Carrying Reported Amount Fair Value Disclosure [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Variable interest entity loans payable | 12 |  | 3 |
Liabilities Of Consolidated Vies [Member] | Fair Value [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Variable interest entity loans payable | 12 |  | 3 |
Liabilities Of Consolidated Vies [Member] | Fair Value [Member] | Fair Value Inputs Level 1 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Variable interest entity loans payable | 0 |  | 0 |
Liabilities Of Consolidated Vies [Member] | Fair Value [Member] | Fair Value Inputs Level 2 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Variable interest entity loans payable | 0 |  | 0 |
Liabilities Of Consolidated Vies [Member] | Fair Value [Member] | Fair Value Inputs Level 3 [Member] |  |  |  |
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] |  |  |  |
Variable interest entity loans payable | $ 12 |  | $ 3 |
[1] | The carry value includes the complex interest calculations embedded in certain MTNs elected to be accounted for as separate derivatives that are reported together with the host contract. As of December 31, 2024, the Company had no embedded derivative assets and had embedded derivative liabilities of $2 million.
[2] | The carry value includes the complex interest calculations embedded in certain MTNs elected to be accounted for as separate derivatives that are reported together with the host contract. As of December 31, 2023, the Company had embedded derivative assets and liabilities of $1 million and $3 million, respectively.

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- Definition Fair value portion of investments in an entity not consolidated. Includes, but is not limited to, investments in an entity that is affiliated with the reporting entity by means of direct or indirect ownership, an entity in which the reporting entity shares control of the entity with another party or group, an entity which the company has significant influence, but does not have control and subsidiaries that are not required to be consolidated and are accounted for using the equity or cost method. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2E -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
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