Equity Securities - (Summary of Investments in Non Marketable Equity Securities) (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Equity Securities Without Readily Determinable Fair Value [Line Items]
Carrying amount	$ 456	$ 441
Non Marketable Equity Securities
Equity Securities Without Readily Determinable Fair Value [Line Items]
Cost	241	215
Unrealized gains	215	226
Carrying amount	$ 456	$ 441

Equity securities without readily determinable fair value, cost.

No definition available.

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- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714

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- Definition

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

No definition available.

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- Definition

Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714

+ Details

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