Commitments and Contingencies - Financial instruments with off-Balance Sheet credit risk (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Commitments to extend credit | Credit card lines
Commitments and contingencies
Unused commitments to extend credit	$ 5,727,176	$ 5,382,089
Commitments to extend credit | Commercial and construction lines of credit
Commitments and contingencies
Unused commitments to extend credit	3,982,769	3,830,601
Commitments to extend credit | Other consumer unused credit commitments
Commitments and contingencies
Unused commitments to extend credit	249,490	250,229
Commercial letters of credit
Commitments and contingencies
Unused commitments to extend credit	1,991	3,260
Standby letters of credit
Commitments and contingencies
Unused commitments to extend credit	31,437	27,848
Commitments to originate or fund mortgage loans
Commitments and contingencies
Unused commitments to extend credit	$ 121,631	$ 95,372