Derivatives and Hedging Activities - Schedule of Credit Derivatives Sold and Held (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Credit Derivatives [Line Items]
Notional Amount	$ 10	$ 2
Payment / Performance Risk	0.00%	0.00%
Other
Credit Derivatives [Line Items]
Notional Amount	$ 10	$ 2
Average Term (Years)	4 years 1 month 2 days	7 years 7 months 20 days
Payment / Performance Risk	1.74%	2.03%