Securities (Details Textual) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 39,400		$ 33,400
Trading	3,956	$ 3,720
Debt Securities, Available-for-sale	1,552,731	1,571,148
Debt Securities, Available-for-sale, Past due	0	0
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity	0	0
Debt Securities, Available-for-sale, Past due	0	0
Debt Securities, Available-for-sale, Nonaccrual	0	0
Debt Securities, Held-to-maturity, Nonaccrual	0	0
Securities (Textual) [Abstract]
Callable Securities in Investment Portfolio	26,200
Pledged Financial Instruments, Not Separately Reported, Securities	778,700	740,600
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity	0	0
Debt Securities, Held-to-maturity	1,282,441	1,066,818
Equity Securities, FV-NI	22,611	23,173
Debt Securities, Held-to-maturity, 90 Days or More Past Due, Still Accruing	0	0
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	3,400	3,000
Held-to-maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 2,600	$ 2,000