Goodwill and other intangible assets - Intangible assets - Narrative (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Intangible asset amortization expense	$ 872	$ 602
Intangible assets with indefinite lives, excluding goodwill	20,500		$ 18,300
Railroad, Utilities and Energy [Member] \| Pilot [Member] \| Other Assets [Member]
Finite Lived And Indefinite Lived Intangible Assets [Line Items]
Net carrying value	$ 6,600

Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]

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- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

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-Name Accounting Standards Codification
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- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 350
-SubTopic 30
-Name Accounting Standards Codification
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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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