Fair Value Measurements - Recurring (Detail) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2022	Dec. 31, 2021
Available-for-sale Securities [Member]
Fair Value
Investment maturity	10 years
Fair Value, Measurements, Recurring [Member]
Fair Value
Total assets	$ 577	$ 507
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets (Level 1) [Member]
Fair Value
Cash equivalents and money market funds	119	38
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets (Level 1) [Member] \| Equity securities [Member]
Fair Value
Investments	32	25
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Available-for-sale Securities [Member]
Fair Value
Investments	370	395
Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Redeemable Preferred Stock [Member]
Fair Value
Investments	$ 56	$ 49

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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- Definition

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

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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.

+ References

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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/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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The period of time an investment matures.

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