Loans - Financing Receivable, Gross Charge-Offs By Year of Origination (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	$ 1,446,444		$ 1,446,444
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	976,928		976,928
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	476,630		476,630
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	214,484		214,484
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	203,606		203,606
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	488,898		488,898
Financing Receivable, Excluding Accrued Interest, Revolving	2,591,337		2,591,337
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	2,585	$ 2,742	8,638	$ 11,241
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	223,516		223,516
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	110,001		110,001
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	64,978		64,978
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	7,872		7,872
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	32,165		32,165
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	25,839		25,839
Financing Receivable, Excluding Accrued Interest, Revolving	673,106		673,106
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	0	0	17	52
Commercial Real Estate Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	912,619		912,619
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	729,863		729,863
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	430,408		430,408
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	475,943		475,943
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	660,848		660,848
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	1,008,914		1,008,914
Financing Receivable, Excluding Accrued Interest, Revolving	30,441		30,441
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff			2,049
Commercial Real Estate Non-Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1,075,548		1,075,548
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	909,256		909,256
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	524,222		524,222
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	463,306		463,306
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	404,906		404,906
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	733,589		733,589
Financing Receivable, Excluding Accrued Interest, Revolving	104,927		104,927
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff			0
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	615,138		615,138
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	846,488		846,488
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	605,753		605,753
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	292,700		292,700
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	97,730		97,730
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	62,602		62,602
Financing Receivable, Excluding Accrued Interest, Revolving	230,332		230,332
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff			54
Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	2,195	1,849	5,871	4,099
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	8,538	7,022	21,634	21,156
Loans Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff	13,318	$ 11,613	38,263	$ 41,187
Nonperforming Financial Instruments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1,294		1,294
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	4,983		4,983
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	5,439		5,439
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	14,827		14,827
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	4,194		4,194
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	7,793		7,793
Financing Receivable, Excluding Accrued Interest, Revolving	17,316		17,316
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	7,858		7,858
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	156		156
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	344		344
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	2,327		2,327
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	8,381		8,381
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1,071		1,071
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	2,125		2,125
Financing Receivable, Excluding Accrued Interest, Revolving	3,154		3,154
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	3,130		3,130
Nonperforming Financial Instruments [Member] | Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	55		55
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	1,304		1,304
Financing Receivable, Excluding Accrued Interest, Revolving	859		859
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0		0
Nonperforming Financial Instruments [Member] | Commercial Real Estate Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1,138		1,138
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,690		2,690
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	1,228		1,228
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	3,024		3,024
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	3,264		3,264
Financing Receivable, Excluding Accrued Interest, Revolving	494		494
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0		0
Nonperforming Financial Instruments [Member] | Commercial Real Estate Non-Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	3,790		3,790
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	99		99
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	123		123
Financing Receivable, Excluding Accrued Interest, Revolving	0		0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	441		441
Nonperforming Financial Instruments [Member] | Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,517		1,517
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	2,712		2,712
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	1,142		1,142
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	934		934
Financing Receivable, Excluding Accrued Interest, Revolving	12,427		12,427
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	624		624
Nonperforming Financial Instruments [Member] | Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	432		432
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	174		174
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	286		286
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	43		43
Financing Receivable, Excluding Accrued Interest, Revolving	361		361
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	3,663		3,663
Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	171		171
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Revolving	21		21
Financing Receivable, Excluding Accrued Interest, 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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	15,505		15,505
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	4,612		4,612
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	1,310		1,310
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	2,191		2,191
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1,945		1,945
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	2,474		2,474
Financing Receivable, Excluding Accrued Interest, Revolving	7,528		7,528
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	2,698		2,698
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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	162		162
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	738		738
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	727		727
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	880		880
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	532		532
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	187		187
Financing Receivable, Excluding Accrued Interest, Revolving	3,367		3,367
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	2,045		2,045
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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Revolving	0		0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	17		17
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Commercial Real Estate Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	37		37
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	258		258
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	1,754		1,754
Financing Receivable, Excluding Accrued Interest, Revolving	0		0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0		0
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration | Nonperforming Financial Instruments [Member] | Commercial Real Estate Non-Owner Occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Revolving	0		0
Financing Receivable, Excluding Accrued Interest, 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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	20		20
Financing Receivable, Excluding Accrued Interest, Revolving	0		0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	34		34
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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0		0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	431		431
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	1,291		1,291
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1,101		1,101
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	503		503
Financing Receivable, Excluding Accrued Interest, Revolving	2,545		2,545
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0		0
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, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	15,343		15,343
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,837		3,837
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	152		152
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	20		20
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	54		54
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	10		10
Financing Receivable, Excluding Accrued Interest, Revolving	1,616		1,616
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	$ 602		$ 602