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	Sep. 30, 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	2,705		2,585
Medium-term notes	403	[1]	455	[2]
Investment agreements	202		221
Variable interest entity loans payable	6		3
Total liabilities	3,316		3,264
Gross liability (recoverable)	530		522
Ceded recoverable (liability)	17		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	324		287
Medium-term notes	215		291
Investment agreements	221		243
Variable interest entity loans payable	6		3
Total liabilities	766		824
Gross liability (recoverable)	761		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
Variable interest entity loans payable	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	324		287
Medium-term notes	0		0
Investment agreements	0		0
Variable interest entity loans payable	0		0
Total liabilities	324		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	215		291
Investment agreements	221		243
Variable interest entity loans payable	6		3
Total liabilities	442		537
Gross liability (recoverable)	761		837
Ceded recoverable (liability)	$ 19		$ 20

[1] The carry value includes the complex interest calculations embedded derivatives in certain MTNs that are reported together with the host contract. As of September 30, 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 derivatives in certain MTNs 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.