Loans - Financing Receivable, Gross Charge-Offs By Year of Origination (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,213,266		$ 1,213,266
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	645,575		645,575
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	596,772		596,772
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	335,508		335,508
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	303,937		303,937
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	318,214		318,214
Financing Receivable, Revolving	2,342,671		2,342,671
Financing Receivable, Allowance for Credit Loss, Writeoff	3,907	$ 943	10,333	$ 14,259
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	329,675		329,675
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	26,287		26,287
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	52,657		52,657
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	45,169		45,169
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,488		3,488
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	9,365		9,365
Financing Receivable, Revolving	596,664		596,664
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	79	518
Commercial Real Estate Buildings Land And Other Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,028,255		1,028,255
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,458,787		1,458,787
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,637,773		1,637,773
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,174,145		1,174,145
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	724,347		724,347
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,161,426		1,161,426
Financing Receivable, Revolving	133,265		133,265
Financing Receivable, Allowance for Credit Loss, Writeoff			122
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	573,431		573,431
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	578,682		578,682
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	605,020		605,020
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	279,883		279,883
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	27,978		27,978
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	711		711
Financing Receivable, Revolving	239,389		239,389
Financing Receivable, Allowance for Credit Loss, Writeoff			0
Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	2,013	170	4,090	1,500
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	8,007	8,189	24,624	22,147
Loans Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	13,927	$ 9,364	39,248	$ 38,486
Nonperforming Financial Instruments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	27,170		27,170
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	22,063		22,063
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	15,246		15,246
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,330		5,330
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,834		1,834
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,344		7,344
Financing Receivable, Revolving	6,643		6,643
Financing Receivable, Revolving, Converted to Term Loan	19,247		19,247
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	22,756		22,756
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,822		2,822
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,335		4,335
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,088		2,088
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	494		494
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,171		2,171
Financing Receivable, Revolving	730		730
Financing Receivable, Revolving, Converted to Term Loan	15,663		15,663
Nonperforming Financial Instruments [Member] | Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	4,086		4,086
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	56		56
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,321		1,321
Financing Receivable, Revolving	2,702		2,702
Financing Receivable, Revolving, Converted to Term Loan	0		0
Nonperforming Financial Instruments [Member] | Commercial Real Estate Buildings Land And Other Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	328		328
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	18,867		18,867
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,911		10,911
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,242		3,242
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,248		1,248
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,594		1,594
Financing Receivable, Revolving	2,718		2,718
Financing Receivable, Revolving, Converted to Term Loan	0		0
Nonperforming Financial Instruments [Member] | Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [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]
Financing Receivable, Allowance for Credit Loss [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	36		36
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,258		2,258
Financing Receivable, Revolving	493		493
Financing Receivable, Revolving, Converted to Term Loan	3,584		3,584
Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	374		374
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
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	16,551		16,551
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	7,995		7,995
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,381		1,381
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	793		793
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	429		429
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,244		1,244
Financing Receivable, Revolving	9,691		9,691
Financing Receivable, Revolving, Converted to Term Loan	1,164		1,164
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	5		5
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,741		1,741
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	755		755
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	487		487
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	402		402
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	625		625
Financing Receivable, Revolving	5,252		5,252
Financing Receivable, Revolving, Converted to Term Loan	1,066		1,066
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	79		79
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
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Commercial Real Estate Buildings Land And Other Loans [Member]
Financing Receivable, Allowance for Credit Loss [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	122		122
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
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [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
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	407		407
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	315		315
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	253		253
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	558		558
Financing Receivable, Revolving	2,490		2,490
Financing Receivable, Revolving, Converted to Term Loan	67		67
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	16,546		16,546
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,768		5,768
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	189		189
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	53		53
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	27		27
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	61		61
Financing Receivable, Revolving	1,949		1,949
Financing Receivable, Revolving, Converted to Term Loan	$ 31		$ 31