Loans and Allowances for Credit Losses, Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2024		Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	$ 898,365			$ 3,743,425
Financing Receivable, Originated, Year Two	3,482,231			4,522,989
Financing Receivable, Originated, Year Three	4,567,033			2,982,784
Financing Receivable, Originated, Year Four	2,761,053			1,756,064
Financing Receivable, Originated, Year Five	1,665,088			1,234,871
Financing Receivable, Originated, More Than Five Years	4,105,179			3,094,093
Financing Receivable, Revolving	6,668,247			6,543,149
Financing Receivable, Revolving, Converted to Term Loan	25,364			27,593
Total	24,172,560			23,904,968
Financing Receivable, Allowance for Credit Loss, Writeoff	7,060		$ 3,667
Commercial [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	692,245			2,698,113
Financing Receivable, Originated, Year Two	2,438,524			2,026,636
Financing Receivable, Originated, Year Three	1,973,600			1,293,089
Financing Receivable, Originated, Year Four	1,214,616			846,923
Financing Receivable, Originated, Year Five	806,174			576,627
Financing Receivable, Originated, More Than Five Years	2,325,449			1,839,613
Financing Receivable, Revolving	5,679,006			5,519,976
Financing Receivable, Revolving, Converted to Term Loan	3,253			2,792
Total	15,132,867			14,803,769
Financing Receivable, Allowance for Credit Loss, Writeoff	4,240		12
Commercial [Member] | Energy [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	58,061			190,122
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	141,197			100,006
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Three	90,222			43,769
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Four	13,033			7,876
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Five	7,447			9,562
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, More Than Five Years	20,724			11,682
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Revolving	3,113,035			3,074,084
Financing Receivable Revolving Writeoff	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Financing Receivable Revolving Converted to Term Writeoff	0			0
Total	3,443,719			3,437,101
Financing Receivable, Allowance for Credit Loss, Writeoff	0			0
Commercial [Member] | Healthcare [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	165,523			650,768
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	654,838			897,730
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Three	924,659			609,244
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Four	593,429			467,993
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Five	441,676			355,026
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			2,500
Financing Receivable, Originated, More Than Five Years	1,175,914			880,099
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	502			0
Financing Receivable, Revolving	289,886			282,358
Financing Receivable Revolving Writeoff	0			0
Financing Receivable, Revolving, Converted to Term Loan	14			15
Financing Receivable Revolving Converted to Term Writeoff	0			0
Total	4,245,939			4,143,233
Financing Receivable, Allowance for Credit Loss, Writeoff	502			2,500
Commercial [Member] | Services [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	183,565			900,090
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	786,684			541,573
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Three	529,263			405,205
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	0			3,060
Financing Receivable, Originated, Year Four	383,174			230,823
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Five	221,695			110,618
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, More Than Five Years	742,303			651,745
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Revolving	681,453			735,561
Financing Receivable Revolving Writeoff	0			2,642
Financing Receivable, Revolving, Converted to Term Loan	1,284			608
Financing Receivable Revolving Converted to Term Writeoff	0			0
Total	3,529,421			3,576,223
Financing Receivable, Allowance for Credit Loss, Writeoff	0			5,702
Commercial [Member] | General business [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	285,096			957,133
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	855,805			487,327
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	27			0
Financing Receivable, Originated, Year Three	429,456			234,871
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	1,399			4,598
Financing Receivable, Originated, Year Four	224,980			140,231
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			2
Financing Receivable, Originated, Year Five	135,356			101,421
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, More Than Five Years	386,508			296,087
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	158			48
Financing Receivable, Revolving	1,594,632			1,427,973
Financing Receivable Revolving Writeoff	2,154			10
Financing Receivable, Revolving, Converted to Term Loan	1,955			2,169
Financing Receivable Revolving Converted to Term Writeoff	0			38
Total	3,913,788			3,647,212
Financing Receivable, Allowance for Credit Loss, Writeoff	3,738			4,696
Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	18,763			399,883
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	421,936			1,942,389
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Three	2,059,848			1,194,762
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Four	1,061,396			416,647
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Five	386,041			520,725
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, More Than Five Years	1,168,870			727,146
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	1,250			8,446
Financing Receivable, Revolving	119,823			136,095
Financing Receivable Revolving Writeoff	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Financing Receivable Revolving Converted to Term Writeoff	0			0
Total	5,236,677			5,337,647
Financing Receivable, Allowance for Credit Loss, Writeoff	1,250		2,208	8,446
Loans to individuals [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	187,357			645,429
Financing Receivable, Originated, Year Two	621,771			553,964
Financing Receivable, Originated, Year Three	533,585			494,933
Financing Receivable, Originated, Year Four	485,041			492,494
Financing Receivable, Originated, Year Five	472,873			137,519
Financing Receivable, Originated, More Than Five Years	610,860			527,334
Financing Receivable, Revolving	869,418			887,078
Financing Receivable, Revolving, Converted to Term Loan	22,111			24,801
Total	3,803,016			3,763,552
Financing Receivable, Allowance for Credit Loss, Writeoff	1,570		$ 1,447
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	96,002			426,325
Financing Receivable Year One Originated Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Two	406,069			322,442
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, Year Three	319,631			343,295
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	0			51
Financing Receivable, Originated, Year Four	337,232			351,647
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	0			4
Financing Receivable, Originated, Year Five	343,768			55,200
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0			0
Financing Receivable, Originated, More Than Five Years	294,117			255,920
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	2			17
Financing Receivable, Revolving	373,771			381,158
Financing Receivable Revolving Writeoff	5			0
Financing Receivable, Revolving, Converted to Term Loan	21,994			24,653
Financing Receivable Revolving Converted to Term Writeoff	0			1
Total	2,192,584			2,160,640
Financing Receivable, Allowance for Credit Loss, Writeoff	7			73
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			633
Financing Receivable, Originated, Year Two	361			1,788
Financing Receivable, Originated, Year Three	3,012			2,220
Financing Receivable, Originated, Year Four	2,204			4,577
Financing Receivable, Originated, Year Five	4,086			6,816
Financing Receivable, Originated, More Than Five Years	129,793			133,773
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	139,456			149,807
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	91,355			218,471
Financing Receivable Year One Originated Current Fiscal Year Writeoff	1,461	[1]		5,636	[2]
Financing Receivable, Originated, Year Two	215,341			229,734
Financing Receivable Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff	40	[1]		82	[2]
Financing Receivable, Originated, Year Three	210,942			149,418
Financing Receivable Year Three Originated Two Years Before Current Fiscal Year Writeoff	45	[1]		96	[2]
Financing Receivable, Originated, Year Four	145,605			136,270
Financing Receivable Year Four Originated Three Years Before Current Fiscal Year Writeoff	12	[1]		43	[2]
Financing Receivable, Originated, Year Five	125,019			75,503
Financing Receivable Year Five Originated Four Years Before Current Fiscal Year Writeoff	0	[1]		0	[2]
Financing Receivable, Originated, More Than Five Years	186,950			137,641
Financing Receivable Originated More than Five Years Before Current Fiscal Year Writeoff	0	[1]		10	[2]
Financing Receivable, Revolving	495,647			505,920
Financing Receivable Revolving Writeoff	0	[1]		6	[2]
Financing Receivable, Revolving, Converted to Term Loan	117			148
Financing Receivable Revolving Converted to Term Writeoff	5	[1]		26	[2]
Total	1,470,976			1,453,105
Financing Receivable, Allowance for Credit Loss, Writeoff	1,563	[1]		5,899	[2]
Performing [Member] | Commercial [Member] | Energy [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	58,061			190,122
Financing Receivable, Originated, Year Two	141,197			100,006
Financing Receivable, Originated, Year Three	90,222			43,769
Financing Receivable, Originated, Year Four	13,033			7,876
Financing Receivable, Originated, Year Five	7,447			9,562
Financing Receivable, Originated, More Than Five Years	20,635			11,583
Financing Receivable, Revolving	3,067,570			3,025,590
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	3,398,165			3,388,508
Performing [Member] | Commercial [Member] | Energy [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	0			0
Financing Receivable, Revolving	13,950			13,950
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	13,950			13,950
Performing [Member] | Commercial [Member] | Energy [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	0			0
Financing Receivable, Revolving	16,613			16,800
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	16,613			16,800
Performing [Member] | Commercial [Member] | Healthcare [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	165,523			650,768
Financing Receivable, Originated, Year Two	638,346			895,602
Financing Receivable, Originated, Year Three	924,230			590,736
Financing Receivable, Originated, Year Four	573,778			409,001
Financing Receivable, Originated, Year Five	382,923			331,897
Financing Receivable, Originated, More Than Five Years	1,095,684			809,858
Financing Receivable, Revolving	288,056			281,378
Financing Receivable, Revolving, Converted to Term Loan	14			15
Total	4,068,554			3,969,255
Performing [Member] | Commercial [Member] | Healthcare [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	15,000			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	1,254			21,791
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	20,027			31,235
Financing Receivable, Revolving	855			5
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	37,136			53,031
Performing [Member] | Commercial [Member] | Healthcare [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	1,492			2,128
Financing Receivable, Originated, Year Three	429			18,508
Financing Receivable, Originated, Year Four	18,397			6,911
Financing Receivable, Originated, Year Five	58,753			0
Financing Receivable, Originated, More Than Five Years	10,896			10,896
Financing Receivable, Revolving	975			975
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	90,942			39,418
Performing [Member] | Commercial [Member] | Services [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	183,565			900,090
Financing Receivable, Originated, Year Two	786,684			526,776
Financing Receivable, Originated, Year Three	514,841			401,872
Financing Receivable, Originated, Year Four	380,227			228,818
Financing Receivable, Originated, Year Five	219,684			106,112
Financing Receivable, Originated, More Than Five Years	725,856			643,477
Financing Receivable, Revolving	677,588			730,729
Financing Receivable, Revolving, Converted to Term Loan	534			595
Total	3,488,979			3,538,469
Performing [Member] | Commercial [Member] | Services [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			1,085
Financing Receivable, Originated, Year Three	1,042			1,520
Financing Receivable, Originated, Year Four	1,305			1,341
Financing Receivable, Originated, Year Five	1,321			534
Financing Receivable, Originated, More Than Five Years	9,243			4,522
Financing Receivable, Revolving	31			81
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	12,942			9,083
Performing [Member] | Commercial [Member] | Services [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			13,712
Financing Receivable, Originated, Year Three	13,380			178
Financing Receivable, Originated, Year Four	155			326
Financing Receivable, Originated, Year Five	341			3,972
Financing Receivable, Originated, More Than Five Years	7,204			3,746
Financing Receivable, Revolving	2,351			3,108
Financing Receivable, Revolving, Converted to Term Loan	750			13
Total	24,181			25,055
Performing [Member] | Commercial [Member] | General business [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	285,096			942,468
Financing Receivable, Originated, Year Two	845,326			436,832
Financing Receivable, Originated, Year Three	383,429			224,735
Financing Receivable, Originated, Year Four	215,106			138,951
Financing Receivable, Originated, Year Five	134,121			101,100
Financing Receivable, Originated, More Than Five Years	378,163			287,744
Financing Receivable, Revolving	1,569,156			1,389,128
Financing Receivable, Revolving, Converted to Term Loan	1,945			2,164
Total	3,812,342			3,523,122
Performing [Member] | Commercial [Member] | General business [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			10,264
Financing Receivable, Originated, Year Two	6,110			16,167
Financing Receivable, Originated, Year Three	8,244			8,420
Financing Receivable, Originated, Year Four	8,594			1,253
Financing Receivable, Originated, Year Five	0			321
Financing Receivable, Originated, More Than Five Years	1,602			8,295
Financing Receivable, Revolving	10,611			897
Financing Receivable, Revolving, Converted to Term Loan	6			0
Total	35,167			45,617
Performing [Member] | Commercial [Member] | General business [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			4,401
Financing Receivable, Originated, Year Two	3,375			33,194
Financing Receivable, Originated, Year Three	37,682			1,716
Financing Receivable, Originated, Year Four	1,280			27
Financing Receivable, Originated, Year Five	1,235			0
Financing Receivable, Originated, More Than Five Years	6,701			0
Financing Receivable, Revolving	9,003			31,992
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	59,276			71,330
Performing [Member] | Commercial real estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	18,763			396,891
Financing Receivable, Originated, Year Two	418,504			1,941,913
Financing Receivable, Originated, Year Three	2,059,848			1,194,759
Financing Receivable, Originated, Year Four	1,061,396			416,647
Financing Receivable, Originated, Year Five	386,041			513,555
Financing Receivable, Originated, More Than Five Years	1,127,922			705,092
Financing Receivable, Revolving	119,823			136,095
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	5,192,297			5,304,952
Performing [Member] | Commercial real estate [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	440			476
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	16,527			19,171
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	16,967			19,647
Performing [Member] | Commercial real estate [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			2,992
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			3
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	5,326			2,733
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	5,326			5,728
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	96,002			426,089
Financing Receivable, Originated, Year Two	405,724			320,733
Financing Receivable, Originated, Year Three	319,050			342,927
Financing Receivable, Originated, Year Four	336,878			349,742
Financing Receivable, Originated, Year Five	343,246			54,801
Financing Receivable, Originated, More Than Five Years	284,962			243,356
Financing Receivable, Revolving	367,761			375,739
Financing Receivable, Revolving, Converted to Term Loan	21,386			23,895
Total	2,175,009			2,137,282
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			157
Financing Receivable, Originated, Year Two	225			140
Financing Receivable, Originated, Year Three	167			131
Financing Receivable, Originated, Year Four	3			1,361
Financing Receivable, Originated, Year Five	0			18
Financing Receivable, Originated, More Than Five Years	161			134
Financing Receivable, Revolving	3,290			2,982
Financing Receivable, Revolving, Converted to Term Loan	0			93
Total	3,846			5,016
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			150
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			37
Financing Receivable, Originated, More Than Five Years	0			49
Financing Receivable, Revolving	279			50
Financing Receivable, Revolving, Converted to Term Loan	1			0
Total	280			286
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			633
Financing Receivable, Originated, Year Two	361			1,788
Financing Receivable, Originated, Year Three	3,012			2,220
Financing Receivable, Originated, Year Four	2,204			4,297
Financing Receivable, Originated, Year Five	3,806			6,441
Financing Receivable, Originated, More Than Five Years	120,856			124,719
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	130,239			140,098
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	91,355			218,401
Financing Receivable, Originated, Year Two	215,282			229,580
Financing Receivable, Originated, Year Three	210,876			149,291
Financing Receivable, Originated, Year Four	145,542			136,215
Financing Receivable, Originated, Year Five	124,996			75,348
Financing Receivable, Originated, More Than Five Years	186,791			137,629
Financing Receivable, Revolving	493,653			503,841
Financing Receivable, Revolving, Converted to Term Loan	100			145
Total	1,468,595			1,450,450
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			66
Financing Receivable, Originated, Year Two	28			39
Financing Receivable, Originated, Year Three	13			106
Financing Receivable, Originated, Year Four	51			30
Financing Receivable, Originated, Year Five	13			8
Financing Receivable, Originated, More Than Five Years	3			0
Financing Receivable, Revolving	0			1,918
Financing Receivable, Revolving, Converted to Term Loan	0			3
Total	108			2,170
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			64
Financing Receivable, Originated, Year Three	24			12
Financing Receivable, Originated, Year Four	0			9
Financing Receivable, Originated, Year Five	1			144
Financing Receivable, Originated, More Than Five Years	144			0
Financing Receivable, Revolving	1,962			3
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	2,131			232
Nonperforming Financial Instruments [Member] | Commercial [Member] | Energy [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	89			99
Financing Receivable, Revolving	14,902			17,744
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	14,991			17,843
Nonperforming Financial Instruments [Member] | Commercial [Member] | Healthcare [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			30,290
Financing Receivable, Originated, Year Five	0			23,129
Financing Receivable, Originated, More Than Five Years	49,307			28,110
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	49,307			81,529
Nonperforming Financial Instruments [Member] | Commercial [Member] | Services [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			1,635
Financing Receivable, Originated, Year Four	1,487			338
Financing Receivable, Originated, Year Five	349			0
Financing Receivable, Originated, More Than Five Years	0			0
Financing Receivable, Revolving	1,483			1,643
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	3,319			3,616
Nonperforming Financial Instruments [Member] | Commercial [Member] | General business [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	994			1,134
Financing Receivable, Originated, Year Three	101			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			0
Financing Receivable, Originated, More Than Five Years	42			48
Financing Receivable, Revolving	5,862			5,956
Financing Receivable, Revolving, Converted to Term Loan	4			5
Total	7,003			7,143
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	2,992			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			0
Financing Receivable, Originated, Year Five	0			7,170
Financing Receivable, Originated, More Than Five Years	19,095			150
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	22,087			7,320
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			79
Financing Receivable, Originated, Year Two	120			1,419
Financing Receivable, Originated, Year Three	414			237
Financing Receivable, Originated, Year Four	351			544
Financing Receivable, Originated, Year Five	522			344
Financing Receivable, Originated, More Than Five Years	8,994			12,381
Financing Receivable, Revolving	2,441			2,387
Financing Receivable, Revolving, Converted to Term Loan	607			665
Total	13,449			18,056
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			0
Financing Receivable, Originated, Year Two	0			0
Financing Receivable, Originated, Year Three	0			0
Financing Receivable, Originated, Year Four	0			280
Financing Receivable, Originated, Year Five	280			375
Financing Receivable, Originated, More Than Five Years	8,937			9,054
Financing Receivable, Revolving	0			0
Financing Receivable, Revolving, Converted to Term Loan	0			0
Total	9,217			9,709
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Personal [Member] | Nonaccrual [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, Year One	0			4
Financing Receivable, Originated, Year Two	31			51
Financing Receivable, Originated, Year Three	29			9
Financing Receivable, Originated, Year Four	12			16
Financing Receivable, Originated, Year Five	9			3
Financing Receivable, Originated, More Than Five Years	12			12
Financing Receivable, Revolving	32			158
Financing Receivable, Revolving, Converted to Term Loan	17			0
Total	$ 142			$ 253

[1] Includes charge-offs on deposit overdrafts, which are generally charged off at 60 days past due.

[2] Includes charge-offs on deposit overdrafts, which are generally charged off at 60 days past due.