Bank Premises and Equipment - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) branch	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) branch	Sep. 30, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Impairment losses on bank premises	$ 0	$ 1	$ 2	$ 2
Closed In 2023
Property, Plant and Equipment [Line Items]
Number of branches held for sale | branch	28		28
Land and improvements held for sale
Property, Plant and Equipment [Line Items]
Property Transferred To Other Real Estate Owned	$ 18		$ 23
Impairment losses on bank premises	$ 7		$ 8