Loans (Non-Accrual Loans, Segregated by Class of Loan and Year of Origination) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	$ 53,713	$ 61,449
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,630,524	1,397,141
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	693,324	608,464
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	392,408	343,825
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	214,163	258,737
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	150,922	121,652
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	143,292	119,250
Financing Receivable, Revolving	2,075,632	2,019,121
Non-accrual loans	22,582	19,849
Commercial and Industrial Total Energy Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	475,023	524,270
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	9,539	48,853
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	20,991	16,310
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	9,480	8,083
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,110	2,174
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,638	5,346
Financing Receivable, Revolving	483,020	592,094
Non-accrual loans	14,433	23,168
Paycheck Protection Program [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	0	0
Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,761,554	1,629,815
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,257,055	1,086,073
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,008,366	883,701
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	632,020	764,197
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	612,767	495,617
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	825,249	804,894
Financing Receivable, Revolving	59,595	74,403
Non-accrual loans	15,297	15,737
Construction Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	693,192	420,477
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	268,080	452,644
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	178,226	196,170
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,339	2,915
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	484	1,144
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,930	1,758
Financing Receivable, Revolving	160,020	147,575
Non-accrual loans	948	1,684
Total consumer real estate loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	440	993
Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	13	18
Nonperforming Financial Instruments [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	6,687	16,498
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,111	15,154
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	13,851	4,989
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,959	3,719
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,795	2,038
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,423	3,532
Financing Receivable, Revolving	11,566	12,414
Financing Receivable, Revolving, Converted to Term Loan	6,321	3,105
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	636	9,479
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,856	3,351
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,047	1,846
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,820	1,489
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	765	105
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	353	29
Financing Receivable, Revolving	4,635	839
Financing Receivable, Revolving, Converted to Term Loan	5,470	2,711
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	0	2,421
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	6,772
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,358	2,144
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,325	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	359
Financing Receivable, Revolving	6,931	11,193
Financing Receivable, Revolving, Converted to Term Loan	819	279
Nonperforming Financial Instruments [Member] | Paycheck Protection Program [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] | Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	6,038	2,914
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	307	5,031
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,446	999
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	814	2,019
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,030	1,933
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,662	2,736
Financing Receivable, Revolving	0	105
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	1,684
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	948	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	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	211
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	408	408
Financing Receivable, Revolving	0	259
Financing Receivable, Revolving, Converted to Term Loan	32	115
Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	13	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	18
Financing Receivable, Revolving, Converted to Term Loan	$ 0	$ 0