Derivative Instruments and Hedging Activities (Gain (loss) recorded in income) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Total income statement impact	$ (4)	$ 16	$ 14
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives	14	(79)
Hedged items	(14)	79
Total income statement impact	0	0
Asset hedges: Pay-fixed interest rate swaps 1
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives	(22)	224
Hedged items	22	(225)
Total income statement impact	$ 0	$ (1)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
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-Publisher FASB
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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.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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Amount of unrealized gain (loss) included in earnings related to the fair value of the hedged item in an interest rate fair value hedge, offset by the gain (loss) on the hedging instrument to the extent that the fair value hedge is determined to be effective.

+ References

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Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments, as offset by the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

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