Business Combinations - Schedule of Business Acquisition, Pro Forma Information (Details) - CIT Group Inc. - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Business acquisition, pro forma net income (loss)	$ 1,225	$ 1,497
Interest income
Business Acquisition [Line Items]
Business acquisition, pro forma revenue	3,413	2,867
Noninterest income
Business Acquisition [Line Items]
Business acquisition, pro forma revenue	$ 1,705	$ 2,537

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-5

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479328/805-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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