Securities Securities (Reconciliation of amortized cost of held to maturity securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	$ 1,799	$ 729
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(160,671)	(181,139)
Debt Securities, Held-to-maturity, Fair Value	1,519,504	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	1,678,376	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	895	313
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(4,336)	(6,225)
Debt Securities, Held-to-maturity, Fair Value	132,342	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	135,783	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	(71,197)	(77,554)
Debt Securities, Held-to-maturity, Fair Value	450,424	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	521,621	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	896	408
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(73,336)	(83,383)
Debt Securities, Held-to-maturity, Fair Value	815,554	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	887,994	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	(9,936)	(11,755)
Debt Securities, Held-to-maturity, Fair Value	90,718	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	100,654	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	(1,866)	(2,222)
Debt Securities, Held-to-maturity, Fair Value	28,958	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	30,824	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	8	8
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Fair Value	1,508	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