Bank Premises and Equipment - Additional Information (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023 USD ($) branch	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) branch	Jun. 30, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Impairment losses on bank premises \| $	$ 0	$ 1	$ 1	$ 1
Closed in 2022
Property, Plant and Equipment [Line Items]
Number of branches held for sale \| branch	24		24

The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482130/360-10-45-15

Name:	us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration