Commitments and Contingencies - Financial instruments with off-Balance Sheet credit risk (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Commitments to extend credit | Credit card lines
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	$ 6,008,516	$ 5,853,990
Commitments to extend credit | Commercial and construction lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	4,381,533	4,425,825
Commitments to extend credit | Other consumer unused credit commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	249,211	250,271
Commercial letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	2,256	3,351
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	29,404	27,868
Commitments to originate or fund mortgage loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	$ 43,593	$ 45,170