Derivative instruments - Hedged Liabilities and Related Cumulative Basis Adjustments (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Cumulative amounts of fair value hedging adjustments related to the carrying amounts of the hedged liabilities	$ (436)	$ (437)
Current portion of long-term debt
Derivative [Line Items]
Hedged Liability, Fair Value Hedge	1,416	82
Cumulative amounts of fair value hedging adjustments related to the carrying amounts of the hedged liabilities	16	82
Carrying value with discontinued hedging relationships	80	82
Hedging adjustments on discontinued hedging relationships	80	82
Long-term debt
Derivative [Line Items]
Hedged Liability, Fair Value Hedge	4,688	6,017
Cumulative amounts of fair value hedging adjustments related to the carrying amounts of the hedged liabilities	(452)	(519)
Carrying value with discontinued hedging relationships	318	357
Hedging adjustments on discontinued hedging relationships	$ 218	$ 257

Hedged Liability, Discontinued Fair Value Hedge

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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 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk, remaining after discontinued hedge.

+ References

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

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- Definition

Amount of liability hedged in fair value hedging relationship.

+ References

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

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

+ References

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

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