Debt - Narrative (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Short term borrowings	$ 139,000,000	$ 102,647,000
Maturity of federal funds purchased from correspondent banks	one business day
Current borrowing available	$ 1,300,000,000
Maximum borrowing capacity	1,700,000,000
FHLB
Debt Instrument [Line Items]
Letter of credit outstanding, amount	226,000,000	189,000,000
Other Correspondent Banks
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity	35,000,000
Outstanding drawings	$ 0	$ 0