Loans - Financing Receivable, Gross Charge-Offs By Year of Origination (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,391,552		$ 1,391,552
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	877,000		877,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	528,835		528,835
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	396,428		396,428
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	193,707		193,707
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	234,603		234,603
Financing Receivable, Revolving	2,152,870		2,152,870
Financing Receivable, Allowance for Credit Loss, Writeoff	943	$ 572	14,259	$ 5,918
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	331,902		331,902
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	72,578		72,578
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	79,911		79,911
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,162		4,162
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,237		7,237
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,874		4,874
Financing Receivable, Revolving	497,025		497,025
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	518	371
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	1,217,271		1,217,271
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,776,671		1,776,671
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,414,317		1,414,317
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	871,262		871,262
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	568,451		568,451
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,012,988		1,012,988
Financing Receivable, Revolving	228,252		228,252
Financing Receivable, Allowance for Credit Loss, Writeoff			62
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	419,819		419,819
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	555,411		555,411
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	369,185		369,185
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	47,871		47,871
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	305		305
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,638		1,638
Financing Receivable, Revolving	150,437		150,437
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	170	68	1,500	430
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	8,189	6,549	22,147	17,642
Loans Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	9,364	$ 7,189	38,486	$ 25,063
Nonperforming Financial Instruments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	26,586		26,586
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	464		464
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	380		380
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	841		841
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,958		7,958
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,971		3,971
Financing Receivable, Revolving	26,426		26,426
Financing Receivable, Revolving, Converted to Term Loan	549		549
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [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	359		359
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	84		84
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	747		747
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,812		2,812
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,068		1,068
Financing Receivable, Revolving	21,924		21,924
Financing Receivable, Revolving, Converted to Term Loan	332		332
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	8,148		8,148
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	56		56
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,348		1,348
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0		0
Financing Receivable, Revolving	4,502		4,502
Financing Receivable, Revolving, Converted to Term Loan	146		146
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	18,438		18,438
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	105		105
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	296		296
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0		0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,463		1,463
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,810		2,810
Financing Receivable, Revolving	0		0
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	38		38
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,335		2,335
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	93		93
Financing Receivable, Revolving	0		0
Financing Receivable, Revolving, Converted to Term Loan	71		71
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	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]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	15,667		15,667
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,341		5,341
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	518		518
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	66		66
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	26		26
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	244		244
Financing Receivable, Revolving	10,376		10,376
Financing Receivable, Revolving, Converted to Term Loan	6,248		6,248
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	124		124
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	952		952
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	178		178
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	54		54
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	25		25
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	29		29
Financing Receivable, Revolving	7,594		7,594
Financing Receivable, Revolving, Converted to Term Loan	5,303		5,303
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	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	518		518
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	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	62		62
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	0		0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	280		280
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	130		130
Financing Receivable, Revolving	1,090		1,090
Financing Receivable, 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, Year One, Originated, Current Fiscal Year	15,543		15,543
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	4,389		4,389
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	60		60
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	12		12
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1		1
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	23		23
Financing Receivable, Revolving	1,692		1,692
Financing Receivable, Revolving, Converted to Term Loan	$ 427		$ 427