Derivative Instruments (Fair Value Hedge Attributable to Foreign Currency) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Foreign Exchange Contract \| Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ 0	$ 0	$ 0	$ 0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	0	0	0
Foreign Exchange Contract \| Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	0	0	0
Foreign Exchange Contract \| Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	3	0	2
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	(4)	0	(4)
Interest Rate Contract \| Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	2	(3)	22	(5)
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	(1)	1	(26)	2
Interest Rate Contract \| Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	0	0	0
Interest Rate Contract \| Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	0	0	0
Financial Futures \| Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	0	0	0	0
Financial Futures \| Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	1	(4)	14	(4)
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	(1)	2	(14)	2
Financial Futures \| Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	$ 0	$ 0	$ 0	$ 0

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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-Topic 815
-SubTopic 25
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-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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-Topic 815
-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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