Loans (Non-Accrual Loans, Segregated by Class of Loan and Year of Origination) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	$ 60,907	$ 37,833
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,619,306	1,703,185
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	768,246	657,039
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	491,938	498,213
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	364,446	241,997
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	182,089	138,541
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	219,766	195,754
Financing Receivable, Revolving	2,247,752	2,170,182
Non-accrual loans	19,545	18,130
Commercial and Industrial Total Energy Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	277,722	352,224
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	61,500	100,862
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	74,631	5,312
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,835	8,659
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6,876	3,078
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,541	2,913
Financing Receivable, Revolving	495,329	408,022
Non-accrual loans	11,500	15,224
Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,645,223	1,901,888
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,785,624	1,528,173
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,253,062	1,009,197
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	811,574	745,031
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	522,566	410,327
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	953,768	882,021
Financing Receivable, Revolving	229,733	120,958
Non-accrual loans	22,420	3,552
Construction Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	560,720	666,024
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	576,374	491,563
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	344,641	130,888
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	28,063	2,236
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	296	486
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,613	1,726
Financing Receivable, Revolving	169,017	181,180
Non-accrual loans	0	0
Total consumer real estate loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	7,442	927
Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	0	0
Nonperforming Financial Instruments [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	25,974	6,301
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	359	1,510
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,785	1,161
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,079	4,845
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6,310	1,473
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,209	1,700
Financing Receivable, Revolving	5,711	10,604
Financing Receivable, Revolving, Converted to Term Loan	17,480	10,239
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	359	1,252
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,635	1,089
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	985	3,242
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,257	1,197
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,006	191
Financing Receivable, Revolving	9	2,973
Financing Receivable, Revolving, Converted to Term Loan	14,294	8,186
Nonperforming Financial Instruments [Member] | Commercial and Industrial Total Energy Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	5,875	4,657
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	72
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	56	1,386
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,321	10
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	4,102	7,631
Financing Receivable, Revolving, Converted to Term Loan	146	1,468
Nonperforming Financial Instruments [Member] | Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	20,099	1,644
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	150	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	217
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,451	266
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	720	1,425
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	0	0
Nonperforming Financial Instruments [Member] | Construction Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	0	0
Nonperforming Financial Instruments [Member] | Total consumer real estate loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	258
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	38	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,281	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	483	84
Financing Receivable, Revolving	1,600	0
Financing Receivable, Revolving, Converted to Term Loan	3,040	585
Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	$ 0	$ 0