Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Net fair value of the interest rate lock commitments	$ 5
Change in the fair value of the interest rate lock commitments, due to decrease in current interest rates of 25 bps	1
Change in the fair value of the interest rate lock commitments, due to decrease in current interest rates of 50 bps	3
Change in the fair value of the interest rate lock commitments, due to increase in current interest rates of 25 bps	2
Change in the fair value of the interest rate lock commitments, due to increase in current interest rates of 50 bps	4
Change in fair value of interest rate lock commitments, due to 20% favorable changes in the assumed loan closing rates	0
Change in fair value of interest rate lock commitments, due to 20% adverse changes in the assumed loan closing rates	0
Change in fair value of interest rate lock commitments, due to 10% favorable changes in the assumed loan closing rates	0
Change in fair value of interest rate lock commitments, due to 10% adverse changes in the assumed loan closing rates	0
Gain resulting from observable price changes	9	$ 0
Positive adjustments, cumulative amount	18
Private equity, impairment	0	1
Private equity, cumulative impairment	15
Residential Mortgage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value changes included in earnings for instruments for which the fair value option was elected	11	$ 8
FVO valuation adjustments related to instrument-specific credit risk	$ 0		$ 0

Sensitivity analysis of decrease in fair value of derivatives impact of fifty basis point increase in interest rate.

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- Definition

Sensitivity analysis of decrease in fair value of derivatives impact of twenty five basis point increase in interest rate.

+ References

No definition available.

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Sensitivity analysis of increase in fair value of derivatives impact of fifty basis point decrease in interest rate.

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Sensitivity Analysis Of Increase In Fair Value Of Derivatives Impact Of Ten Percent Changes In Assumed Loan Closing Rates, Adverse

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Sensitivity Analysis Of Increase In Fair Value Of Derivatives Impact Of Ten Percent Changes In Assumed Loan Closing Rates, Favorable

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Sensitivity analysis of increase in fair value of derivatives impact of twenty five basis point decrease in interest rate.

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-SubTopic 10
-Topic 815
-Publisher FASB
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- Definition

Amount of impairment loss on investment in equity security without readily determinable fair value.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479536/321-10-50-3

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Amount of cumulative impairment loss on investment in equity security without readily determinable fair value.

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Amount of gain from upward price adjustment on investment in equity security without readily determinable fair value.

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-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
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Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.

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- Definition

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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- Definition

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

+ References

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-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 30
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This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets.

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