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Derivatives - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	$ 7,141,000,000		$ 7,141,000,000		$ 12,363,000,000
Derivative, Collateral, Right to Reclaim Cash	26,000,000		26,000,000		25,000,000
Cash collateral held	57,000,000		57,000,000		49,000,000
Securities Received as Collateral	0		0		0
Collateral Securities Repledged, Delivered, or Used	0		0		0
Collateral Pledged
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Collateral, Right to Reclaim Cash	10,000,000		10,000,000		16,000,000
Asset Pledged as Collateral [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Collateral, Right to Reclaim Securities	11,000,000		11,000,000		14,000,000
Asset Pledged as Collateral [Member] \| Over the Counter [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Collateral, Right to Reclaim Securities	96,000,000		96,000,000		112,000,000
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring	0	$ 0	0	$ 0
AOCI Attributable to Parent [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			35,000,000
Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	2,382,000,000		2,382,000,000		8,269,000,000
Interest rate swaps \| Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	344,000,000		344,000,000		$ 6,600,000,000
SOFR Plus Two Point One Two Five Percent Plus Zero Point Two Six One Six One Percent Junior Subordinated Notes Due Two Thousand Sixty Seven
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Junior Subordinated Debentures	$ 500,000,000		$ 500,000,000