Regulatory Capital - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer	7.64%	5.06%
FCB
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer	7.36%	4.99%
Dividend restrictions, additional maximum amount of distribution	$ 8,000
Payments of dividends	$ 367

Banking Regulation, Dividend Restrictions, Maximum Additional Amount Of Distribution

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- Definition

Banking Regulation, Total Risk-Based Capital Ratio, Capital Conservation Buffer

+ References

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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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480696/942-505-50-1

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- Definition

Cash outflow in the form of ordinary dividends to common shareholders, preferred shareholders and noncontrolling interests, generally out of earnings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

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