Fair Value Measurements - Recurring (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2024	Dec. 31, 2023
Fair Value
Debt instrument repurchase amount	$ 778
Debt Securities [Member]
Fair Value
Investment maturity	10 years
Fair Value, Recurring [Member]
Fair Value
Total assets	$ 1,379	$ 819
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value
Cash equivalents and money market funds	37	327
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Common Stocks, by Industry [Member]
Fair Value
Available-for-sale securities	68	61
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Debt Securities [Member]
Fair Value
Available-for-sale securities	778
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value
Available-for-sale securities	$ 496	$ 431

Fair value portion of asset recognized for present right to economic benefit.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Fair value amount of debt instrument that was repurchased.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
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The period of time an investment matures.

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