Commitments and contingent liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Commitments to Extend Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 3,840,000	$ 3,500,000
Standby Letters of Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	32,400	36,000
Letter of Credit
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 27	$ 0