Contingencies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Loss Contingencies [Line Items]
Unused commitments to extend credit	$ 5,030,000		$ 5,171,000	$ 5,030,000	$ 5,171,000
Litigation settlement expense	6,500		0	6,500	0
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Potential exposure to credit loss in the event of nonperformance	127,800		140,600	$ 127,800	140,600
Letters of credit, maturity term - maximum				3 years
Collateral held, fair value	32,000		$ 32,600	$ 32,000	$ 32,600
Settlement Agreement [Member]
Loss Contingencies [Line Items]
Payments for legal settlements	6,500					$ 100,000
Litigation settlement expense	$ 6,500	$ 100,000
Legal fees		$ 750