Derivative instruments - Contracts Falling under Early Termination Provisions (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Derivative [Line Items]
Aggregate fair value of OTC derivatives in net liability positions	$ 1,451	$ 381
Collateral posted	1,840	1,009
A3 \| A-
Derivative [Line Items]
Aggregate fair value of OTC derivatives in net liability positions	104	61
Baa2 \| BBB
Derivative [Line Items]
Aggregate fair value of OTC derivatives in net liability positions	266	252
Ba1 \| BB+ and lower
Derivative [Line Items]
Aggregate fair value of OTC derivatives in net liability positions	$ 1,322	$ 714

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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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/2009/role/commonPracticeRef
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- Definition

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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