Segment Information - Reconciliation of Operating Revenues (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Segment Reporting [Line Items]
Operating revenues	$ 34,313	$ 33,821	$ 103,006	$ 101,810
Operating Segments
Segment Reporting [Line Items]
Operating revenues	33,455	32,948	100,435	99,189
Corporate and other
Segment Reporting [Line Items]
Operating revenues	940	958	2,812	2,867
Eliminations
Segment Reporting [Line Items]
Operating revenues	$ (82)	$ (85)	$ (241)	$ (246)

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details

- 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.

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+ Details