Acquisition and Divestitures - Summary of Acquisition, Pro Forma Information (Details) - Peoples United Financial Inc $ in Millions	12 Months Ended
Dec. 31, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total revenues	$ 8,631
Net income	$ 2,158

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/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Name Accounting Standards Codification
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-Paragraph 2
-Publisher FASB
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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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