Securities Securities (Reconciliation of amortized cost of held to maturity securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	$ 342	$ 729
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(180,150)	(181,139)
Debt Securities, Held-to-maturity, Fair Value	1,444,084	1,524,710
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	1,623,892	1,705,120
Small Business Administration Pooled Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	327	313
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(6,424)	(6,225)
Debt Securities, Held-to-maturity, Fair Value	127,218	130,918
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	133,315	136,830
Collateralized Debt Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(77,944)	(77,554)
Debt Securities, Held-to-maturity, Fair Value	428,647	458,417
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	506,591	535,971
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	15	408
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(82,235)	(83,383)
Debt Securities, Held-to-maturity, Fair Value	769,198	815,952
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	851,418	898,927
US Treasury Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(11,509)	(11,755)
Debt Securities, Held-to-maturity, Fair Value	89,164	88,879
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	100,673	100,634
U.S. government agency securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(1,907)	(2,222)
Debt Securities, Held-to-maturity, Fair Value	28,488	29,036
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	30,395	31,258
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	8
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(131)	0
Debt Securities, Held-to-maturity, Fair Value	1,369	1,508
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss	$ 1,500	$ 1,500