Variable Interest Entities - Variable Interest Entities (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Dec. 31, 2023
Variable Interest Entities
Assets	$ 3,011	$ 3,382	$ 3,331
Liabilities	$ 1,621	1,953	1,828
Variable Interest Entities
Variable Interest Entities
Assets		59	84
Liabilities		$ 42	$ 59

Amount of asset recognized for present right to economic benefit.

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+ Details

- Definition

Amount of liability recognized for present obligation requiring transfer or otherwise providing economic benefit to others.

+ References

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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.

+ References + Details