Securities (Details Textual) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 29,900		$ 32,900
Trading	3,439	$ 2,838
Debt Securities, Available-for-sale	794,516	412,860
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	3,300
Pledged Financial Instruments, Not Separately Reported, Securities	447,400	419,600
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity	0	0
Debt Securities, Held-to-maturity	861,821	724,512
Equity Securities, FV-NI	22,975	22,107
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	2,100	1,200
Held-to-maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 1,600	$ 1,500