Commitments and Contingencies - Financial instruments with off-Balance Sheet credit risk (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Commitments to extend credit | Credit card lines
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	$ 6,130,148	$ 6,108,939
Commitments to extend credit | Commercial Lines of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	3,661,556	3,626,269
Commitments to extend credit | Construction Lines of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	1,212,596	1,287,679
Commitments to extend credit | Other consumer unused credit commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	257,059	256,610
Commercial letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	1,234	1,404
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	115,808	80,889
Commitments to originate or fund mortgage loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Unused commitments to extend credit	$ 29,524	$ 32,968