Derivative Instruments and Hedging Activities - Gross Fair Values of Derivatives (Details) - Interest rate swaps - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Derivatives, Fair Value [Line Items]
Assets	$ 1	$ 1
Liabilities	2	1
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	1	1
Liabilities	2	1
Reduction of derivative asset related to variation margin settlements	53	93
Reduction of derivative liability related to variation margin settlements	$ 270	$ 21

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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