Securities Securities (Reconciliation of amortized cost of held to maturity securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	$ 61	$ 559
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(161,707)	(152,058)
Debt Securities, Held-to-maturity, Fair Value	1,383,621	1,417,608
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	1,545,267	1,569,107
Small Business Administration Pooled Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	384
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(7,684)	(6,157)
Debt Securities, Held-to-maturity, Fair Value	121,337	124,653
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	129,021	130,426
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	(71,758)	(69,606)
Debt Securities, Held-to-maturity, Fair Value	393,258	407,911
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	465,016	477,517
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	61	175
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(71,372)	(65,878)
Debt Securities, Held-to-maturity, Fair Value	748,601	763,728
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	819,912	829,431
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	(9,922)	(9,177)
Debt Securities, Held-to-maturity, Fair Value	90,810	91,535
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	100,732	100,712
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	(843)	(1,113)
Debt Securities, Held-to-maturity, Fair Value	28,243	28,408
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	29,086	29,521
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	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(128)	(127)
Debt Securities, Held-to-maturity, Fair Value	1,372	1,373
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