Investment and derivative contract gains (losses) - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Sales of equity securities	$ 40,631	$ 33,664	$ 15,849
Taxable gains (losses) on sales of equity securities	$ 5,000	$ 769	$ 3,600
Pilot Travel Centers LLC [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Equity interest ownership percentage	38.60%			38.60%
Other Investment gains from remeasurement	$ 3,000

Taxable gains (loss) on sales of equity securities.

No definition available.

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- Definition

Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination.

+ References

No definition available.

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- Definition

In a business combination achieved in stages, this element represents the amount of net gain (loss) recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)(2)
-Publisher FASB
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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4E
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4E

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- Definition

Amount of cash inflow from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as investing activity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-19

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-Name Accounting Standards Codification
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-Paragraph 1
-SubTopic 10
-Topic 321
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479567/321-10-45-1

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