Loans - Risk Category of Loans by Class (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]
Total	$ 3,978,919		$ 3,977,900
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Total	1,061	$ 1,238
Commercial and Industrial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	23,816		112,673
Year two	103,087		135,337
Year three	123,939		86,555
Year four	85,341		30,101
Year five	27,276		34,281
Prior	71,701		49,183
Revolving Loans Amortized Cost Basis	137,506		141,411
Total	572,666		589,541
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	4		911
Year three	17		32
Year four	35		493
Year five	0		7
Prior	0		88
Revolving Loans Amortized Cost Basis	46		261
Total	102	733	1,792
Commercial and Industrial Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	23,640		112,626
Year two	103,041		134,590
Year three	123,191		80,738
Year four	81,060		28,492
Year five	25,763		32,585
Prior	66,102		45,764
Revolving Loans Amortized Cost Basis	130,677		134,936
Total	553,474		569,731
Commercial and Industrial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	176		47
Year two	46		453
Year three	477		128
Year four	115		829
Year five	1,208		0
Prior	2,482		1,948
Revolving Loans Amortized Cost Basis	3,526		3,048
Total	8,030		6,453
Commercial and Industrial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		294
Year three	271		5,689
Year four	4,166		780
Year five	305		1,696
Prior	3,117		1,471
Revolving Loans Amortized Cost Basis	3,303		3,427
Total	11,162		13,357
Commercial and Industrial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	77,985		314,475
Year two	330,953		419,892
Year three	421,992		487,582
Year four	465,533		228,461
Year five	212,943		148,419
Prior	601,263		481,090
Revolving Loans Amortized Cost Basis	38,139		41,916
Total	2,148,808		2,121,835
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	0		0
Year three	0		56
Year four	0		0
Year five	0		0
Prior	308		0
Revolving Loans Amortized Cost Basis	0		0
Total	308	0	56
Commercial Real Estate Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	77,809		300,569
Year two	316,801		416,874
Year three	417,934		470,917
Year four	449,347		225,668
Year five	210,315		147,431
Prior	578,412		458,821
Revolving Loans Amortized Cost Basis	37,178		41,102
Total	2,087,796		2,061,382
Commercial Real Estate Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	176		13,906
Year two	13,688		2,401
Year three	2,788		11,155
Year four	10,808		1,651
Year five	2,091		259
Prior	18,596		19,532
Revolving Loans Amortized Cost Basis	961		638
Total	49,108		49,542
Commercial Real Estate Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	464		617
Year three	1,270		5,510
Year four	5,378		1,142
Year five	537		729
Prior	4,255		2,737
Revolving Loans Amortized Cost Basis	0		176
Total	11,904		10,911
Commercial Real Estate Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	13,287		46,443
Year two	45,444		56,455
Year three	53,379		40,954
Year four	39,003		47,514
Year five	45,484		25,755
Prior	135,224		114,968
Revolving Loans Amortized Cost Basis	68,912		91,714
Total	400,733		423,803
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		2
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		25
Total	0	0	27
Agricultural Loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	12,909		44,948
Year two	43,953		56,291
Year three	53,296		39,852
Year four	38,147		42,279
Year five	40,568		23,217
Prior	119,627		100,391
Revolving Loans Amortized Cost Basis	67,641		89,455
Total	376,141		396,433
Agricultural Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	183		1,495
Year two	1,491		164
Year three	83		903
Year four	856		5,047
Year five	4,805		2,338
Prior	10,982		9,894
Revolving Loans Amortized Cost Basis	1,271		2,259
Total	19,671		22,100
Agricultural Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	195		0
Year two	0		0
Year three	0		199
Year four	0		188
Year five	111		200
Prior	4,615		4,683
Revolving Loans Amortized Cost Basis	0		0
Total	4,921		5,270
Agricultural Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	7,886		36,848
Year two	34,090		12,281
Year three	11,224		10,634
Year four	9,498		6,086
Year five	5,086		4,788
Prior	5,712		1,351
Revolving Loans Amortized Cost Basis	0		0
Total	73,496		71,988
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0	0	0
Leases | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	7,886		36,848
Year two	34,090		12,281
Year three	11,224		10,634
Year four	9,498		6,086
Year five	5,086		4,788
Prior	5,712		1,351
Revolving Loans Amortized Cost Basis	0		0
Total	73,496		71,988
Leases | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Leases | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Leases | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	0		0
Year three	0		0
Year four	0		0
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	0		0
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	11,092		49,282
Year two	43,922		21,480
Year three	18,492		9,720
Year four	8,005		2,756
Year five	2,400		917
Prior	2,380		1,912
Revolving Loans Amortized Cost Basis	1,717		1,786
Total	88,008		87,853
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	248		1,162
Year two	75		42
Year three	27		23
Year four	15		71
Year five	0		3
Prior	0		1
Revolving Loans Amortized Cost Basis	3		7
Total	368	345	1,309
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	0		0
Year two	238		417
Year three	1,903		488
Year four	303		150
Year five	236		165
Prior	3,536		1,309
Revolving Loans Amortized Cost Basis	306,643		297,156
Total	312,859		299,685
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	0		0
Year three	35		0
Year four	99		55
Year five	0		0
Prior	0		24
Revolving Loans Amortized Cost Basis	0		15
Total	134	14	94
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one	12,231		56,317
Year two	55,043		65,361
Year three	64,121		86,170
Year four	82,977		41,639
Year five	40,223		17,940
Prior	106,641		95,417
Revolving Loans Amortized Cost Basis	0		0
Total	361,236		362,844
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Year one	0		0
Year two	0		0
Year three	0		22
Year four	0		36
Year five	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Total	$ 0	$ 26	$ 58