Loan and Lease Financings (Details 2)	12 Months Ended
	Dec. 31, 2023 USD ($) class method	Dec. 31, 2022 USD ($)
Receivables [Abstract]
Number of methods to assess credit risk | method	2
Loan and Lease Financings
Total loans and leases	$ 6,518,505,000	$ 6,011,162,000
Number of domestic aircraft loan pools | class	2
Commercial and agricultural
Loan and Lease Financings
Financing receivable originated during current fiscal year	$ 163,158,000	163,808,000
Financing receivable originated one year prior to current fiscal year	127,374,000	113,166,000
Financing receivable originated two years prior to current fiscal year	73,359,000	71,425,000
Financing receivable originated three years prior to current fiscal year	40,209,000	37,968,000
Financing receivable originated four years prior to current fiscal year	18,951,000	18,836,000
Financing receivable originated five years or more prior to current fiscal year	16,274,000	14,900,000
Revolving Loans	326,898,000	391,928,000
Revolving Loans Converted to Term	0	0
Total loans and leases	766,223,000	812,031,000
Current period gross charge-offs, financing receivable originated during current fiscal year	668,000
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	499,000
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	15,000
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	17,000
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	4,000
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	3,102,000
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	$ 4,305,000
Commercial and agricultural | Minimum
Loan and Lease Financings
Expected life of underlying collateral	3 years
Commercial and agricultural | Maximum
Loan and Lease Financings
Expected life of underlying collateral	7 years
Renewable energy
Loan and Lease Financings
Financing receivable originated during current fiscal year	$ 177,364,000	109,393,000
Financing receivable originated one year prior to current fiscal year	23,679,000	113,276,000
Financing receivable originated two years prior to current fiscal year	86,836,000	36,751,000
Financing receivable originated three years prior to current fiscal year	29,138,000	78,330,000
Financing receivable originated four years prior to current fiscal year	56,935,000	19,219,000
Financing receivable originated five years or more prior to current fiscal year	25,756,000	24,194,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	399,708,000	381,163,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	0
Auto and light truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	604,314,000	527,371,000
Financing receivable originated one year prior to current fiscal year	250,549,000	158,874,000
Financing receivable originated two years prior to current fiscal year	64,656,000	67,899,000
Financing receivable originated three years prior to current fiscal year	27,476,000	35,811,000
Financing receivable originated four years prior to current fiscal year	14,205,000	12,738,000
Financing receivable originated five years or more prior to current fiscal year	5,712,000	5,424,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	966,912,000	808,117,000
Current period gross charge-offs, financing receivable originated during current fiscal year	126,000
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	360,000
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	128,000
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	33,000
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	19,000
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	63,000
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	$ 729,000
Auto and light truck | Minimum
Loan and Lease Financings
Loan amortization period	18 months
Direct finance lease term	3 years
Auto and light truck | Maximum
Loan and Lease Financings
Loan amortization period	4 years
Direct finance lease term	7 years
Medium and heavy duty truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	$ 99,819,000	158,296,000
Financing receivable originated one year prior to current fiscal year	121,500,000	66,533,000
Financing receivable originated two years prior to current fiscal year	45,744,000	43,711,000
Financing receivable originated three years prior to current fiscal year	24,645,000	31,980,000
Financing receivable originated four years prior to current fiscal year	16,037,000	10,053,000
Financing receivable originated five years or more prior to current fiscal year	4,202,000	3,289,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	311,947,000	313,862,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	$ 0
Medium and heavy duty truck | Minimum
Loan and Lease Financings
Period of amortization to reach equity position in collateral	3 years
Medium and heavy duty truck | Maximum
Loan and Lease Financings
Period of amortization to reach equity position in collateral	4 years
Aircraft
Loan and Lease Financings
Financing receivable originated during current fiscal year	$ 279,755,000	451,443,000
Financing receivable originated one year prior to current fiscal year	364,650,000	277,979,000
Financing receivable originated two years prior to current fiscal year	201,283,000	219,851,000
Financing receivable originated three years prior to current fiscal year	145,287,000	57,379,000
Financing receivable originated four years prior to current fiscal year	37,244,000	31,085,000
Financing receivable originated five years or more prior to current fiscal year	43,533,000	36,298,000
Revolving Loans	6,420,000	3,687,000
Revolving Loans Converted to Term	0	0
Total loans and leases	1,078,172,000	1,077,722,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	$ 0
Aircraft | Minimum
Loan and Lease Financings
Loan amortization period	10 years
Aircraft | Maximum
Loan and Lease Financings
Loan amortization period	15 years
Construction equipment
Loan and Lease Financings
Financing receivable originated during current fiscal year	$ 466,799,000	496,563,000
Financing receivable originated one year prior to current fiscal year	353,834,000	221,106,000
Financing receivable originated two years prior to current fiscal year	132,875,000	108,892,000
Financing receivable originated three years prior to current fiscal year	65,508,000	61,082,000
Financing receivable originated four years prior to current fiscal year	29,543,000	18,147,000
Financing receivable originated five years or more prior to current fiscal year	7,803,000	4,625,000
Revolving Loans	26,044,000	23,893,000
Revolving Loans Converted to Term	2,346,000	4,195,000
Total loans and leases	1,084,752,000	938,503,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	44,000
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	10,000
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	54,000
Commercial real estate
Loan and Lease Financings
Financing receivable originated during current fiscal year	336,965,000	273,058,000
Financing receivable originated one year prior to current fiscal year	256,368,000	165,889,000
Financing receivable originated two years prior to current fiscal year	151,173,000	129,509,000
Financing receivable originated three years prior to current fiscal year	105,933,000	103,259,000
Financing receivable originated four years prior to current fiscal year	90,824,000	102,318,000
Financing receivable originated five years or more prior to current fiscal year	188,323,000	169,461,000
Revolving Loans	275,000	251,000
Revolving Loans Converted to Term	0	0
Total loans and leases	1,129,861,000	943,745,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	39,000
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	30,000
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	179,000
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	0
Current period gross charge-offs, revolving financing receivable	0
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	248,000
Residential real estate and home equity
Loan and Lease Financings
Financing receivable originated during current fiscal year	87,767,000	115,154,000
Financing receivable originated one year prior to current fiscal year	110,165,000	100,821,000
Financing receivable originated two years prior to current fiscal year	89,532,000	97,898,000
Financing receivable originated three years prior to current fiscal year	88,232,000	34,498,000
Financing receivable originated four years prior to current fiscal year	31,095,000	6,864,000
Financing receivable originated five years or more prior to current fiscal year	72,967,000	82,378,000
Revolving Loans	152,573,000	142,904,000
Revolving Loans Converted to Term	5,642,000	4,220,000
Total loans and leases	637,973,000	584,737,000
Current period gross charge-offs, financing receivable originated during current fiscal year	0
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	0
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	54,000
Current period gross charge-offs, revolving financing receivable	39,000
Current period gross charge-offs, revolving financing receivable converted to term loan	8,000
Current period gross charge-offs	101,000
Consumer
Loan and Lease Financings
Financing receivable originated during current fiscal year	53,086,000	74,406,000
Financing receivable originated one year prior to current fiscal year	48,035,000	34,684,000
Financing receivable originated two years prior to current fiscal year	19,862,000	12,973,000
Financing receivable originated three years prior to current fiscal year	6,317,000	7,428,000
Financing receivable originated four years prior to current fiscal year	2,567,000	2,989,000
Financing receivable originated five years or more prior to current fiscal year	1,027,000	704,000
Revolving Loans	12,063,000	18,098,000
Revolving Loans Converted to Term	0	0
Total loans and leases	142,957,000	151,282,000
Current period gross charge-offs, financing receivable originated during current fiscal year	541,000
Current period gross charge-offs, financing receivable originated one year prior to current fiscal year	455,000
Current period gross charge-offs, financing receivable originated two years prior to current fiscal year	138,000
Current period gross charge-offs, financing receivable originated three years prior to current fiscal year	28,000
Current period gross charge-offs, financing receivable originated four years prior to current fiscal year	17,000
Current period gross charge-offs, financing receivable originated five years prior to current fiscal year	3,000
Current period gross charge-offs, revolving financing receivable	29,000
Current period gross charge-offs, revolving financing receivable converted to term loan	0
Current period gross charge-offs	1,211,000
Credit Quality Grades 1-6 | Commercial and agricultural
Loan and Lease Financings
Financing receivable originated during current fiscal year	155,656,000	159,317,000
Financing receivable originated one year prior to current fiscal year	124,717,000	107,232,000
Financing receivable originated two years prior to current fiscal year	68,473,000	71,365,000
Financing receivable originated three years prior to current fiscal year	39,708,000	35,874,000
Financing receivable originated four years prior to current fiscal year	18,658,000	17,192,000
Financing receivable originated five years or more prior to current fiscal year	15,856,000	13,860,000
Revolving Loans	299,495,000	370,553,000
Revolving Loans Converted to Term	0	0
Total loans and leases	722,563,000	775,393,000
Credit Quality Grades 1-6 | Renewable energy
Loan and Lease Financings
Financing receivable originated during current fiscal year	177,364,000	109,393,000
Financing receivable originated one year prior to current fiscal year	23,679,000	113,276,000
Financing receivable originated two years prior to current fiscal year	86,836,000	35,660,000
Financing receivable originated three years prior to current fiscal year	29,138,000	72,652,000
Financing receivable originated four years prior to current fiscal year	56,935,000	18,518,000
Financing receivable originated five years or more prior to current fiscal year	25,756,000	20,654,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	399,708,000	370,153,000
Credit Quality Grades 1-6 | Auto and light truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	603,406,000	521,399,000
Financing receivable originated one year prior to current fiscal year	248,701,000	155,508,000
Financing receivable originated two years prior to current fiscal year	64,182,000	62,063,000
Financing receivable originated three years prior to current fiscal year	24,986,000	32,975,000
Financing receivable originated four years prior to current fiscal year	13,573,000	10,946,000
Financing receivable originated five years or more prior to current fiscal year	5,287,000	3,476,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	960,135,000	786,367,000
Credit Quality Grades 1-6 | Medium and heavy duty truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	96,254,000	158,296,000
Financing receivable originated one year prior to current fiscal year	114,490,000	66,533,000
Financing receivable originated two years prior to current fiscal year	44,069,000	43,711,000
Financing receivable originated three years prior to current fiscal year	24,645,000	31,980,000
Financing receivable originated four years prior to current fiscal year	15,264,000	10,053,000
Financing receivable originated five years or more prior to current fiscal year	4,202,000	3,274,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	298,924,000	313,847,000
Credit Quality Grades 1-6 | Aircraft
Loan and Lease Financings
Financing receivable originated during current fiscal year	269,635,000	438,481,000
Financing receivable originated one year prior to current fiscal year	355,175,000	273,726,000
Financing receivable originated two years prior to current fiscal year	197,579,000	213,661,000
Financing receivable originated three years prior to current fiscal year	140,744,000	57,379,000
Financing receivable originated four years prior to current fiscal year	37,244,000	31,085,000
Financing receivable originated five years or more prior to current fiscal year	36,936,000	35,012,000
Revolving Loans	6,420,000	3,687,000
Revolving Loans Converted to Term	0	0
Total loans and leases	1,043,733,000	1,053,031,000
Credit Quality Grades 1-6 | Construction equipment
Loan and Lease Financings
Financing receivable originated during current fiscal year	459,884,000	475,854,000
Financing receivable originated one year prior to current fiscal year	333,008,000	213,349,000
Financing receivable originated two years prior to current fiscal year	131,838,000	106,409,000
Financing receivable originated three years prior to current fiscal year	64,998,000	59,204,000
Financing receivable originated four years prior to current fiscal year	29,543,000	17,834,000
Financing receivable originated five years or more prior to current fiscal year	7,803,000	4,593,000
Revolving Loans	26,044,000	23,310,000
Revolving Loans Converted to Term	2,346,000	2,754,000
Total loans and leases	1,055,464,000	903,307,000
Credit Quality Grades 1-6 | Commercial real estate
Loan and Lease Financings
Financing receivable originated during current fiscal year	336,287,000	271,526,000
Financing receivable originated one year prior to current fiscal year	251,055,000	164,173,000
Financing receivable originated two years prior to current fiscal year	148,597,000	121,685,000
Financing receivable originated three years prior to current fiscal year	105,282,000	97,470,000
Financing receivable originated four years prior to current fiscal year	86,452,000	102,271,000
Financing receivable originated five years or more prior to current fiscal year	187,306,000	168,391,000
Revolving Loans	275,000	251,000
Revolving Loans Converted to Term	0	0
Total loans and leases	1,115,254,000	925,767,000
Credit Quality Grades 7-12
Loan and Lease Financings
Threshold value of loan or lease for evaluation of the appropriateness of the impairment reserve	250,000
Credit Quality Grades 7-12 | Commercial and agricultural
Loan and Lease Financings
Financing receivable originated during current fiscal year	7,502,000	4,491,000
Financing receivable originated one year prior to current fiscal year	2,657,000	5,934,000
Financing receivable originated two years prior to current fiscal year	4,886,000	60,000
Financing receivable originated three years prior to current fiscal year	501,000	2,094,000
Financing receivable originated four years prior to current fiscal year	293,000	1,644,000
Financing receivable originated five years or more prior to current fiscal year	418,000	1,040,000
Revolving Loans	27,403,000	21,375,000
Revolving Loans Converted to Term	0	0
Total loans and leases	43,660,000	36,638,000
Credit Quality Grades 7-12 | Renewable energy
Loan and Lease Financings
Financing receivable originated during current fiscal year	0	0
Financing receivable originated one year prior to current fiscal year	0	0
Financing receivable originated two years prior to current fiscal year	0	1,091,000
Financing receivable originated three years prior to current fiscal year	0	5,678,000
Financing receivable originated four years prior to current fiscal year	0	701,000
Financing receivable originated five years or more prior to current fiscal year	0	3,540,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	0	11,010,000
Credit Quality Grades 7-12 | Auto and light truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	908,000	5,972,000
Financing receivable originated one year prior to current fiscal year	1,848,000	3,366,000
Financing receivable originated two years prior to current fiscal year	474,000	5,836,000
Financing receivable originated three years prior to current fiscal year	2,490,000	2,836,000
Financing receivable originated four years prior to current fiscal year	632,000	1,792,000
Financing receivable originated five years or more prior to current fiscal year	425,000	1,948,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	6,777,000	21,750,000
Credit Quality Grades 7-12 | Medium and heavy duty truck
Loan and Lease Financings
Financing receivable originated during current fiscal year	3,565,000	0
Financing receivable originated one year prior to current fiscal year	7,010,000	0
Financing receivable originated two years prior to current fiscal year	1,675,000	0
Financing receivable originated three years prior to current fiscal year	0	0
Financing receivable originated four years prior to current fiscal year	773,000	0
Financing receivable originated five years or more prior to current fiscal year	0	15,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	13,023,000	15,000
Credit Quality Grades 7-12 | Aircraft
Loan and Lease Financings
Financing receivable originated during current fiscal year	10,120,000	12,962,000
Financing receivable originated one year prior to current fiscal year	9,475,000	4,253,000
Financing receivable originated two years prior to current fiscal year	3,704,000	6,190,000
Financing receivable originated three years prior to current fiscal year	4,543,000	0
Financing receivable originated four years prior to current fiscal year	0	0
Financing receivable originated five years or more prior to current fiscal year	6,597,000	1,286,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	34,439,000	24,691,000
Credit Quality Grades 7-12 | Construction equipment
Loan and Lease Financings
Financing receivable originated during current fiscal year	6,915,000	20,709,000
Financing receivable originated one year prior to current fiscal year	20,826,000	7,757,000
Financing receivable originated two years prior to current fiscal year	1,037,000	2,483,000
Financing receivable originated three years prior to current fiscal year	510,000	1,878,000
Financing receivable originated four years prior to current fiscal year	0	313,000
Financing receivable originated five years or more prior to current fiscal year	0	32,000
Revolving Loans	0	583,000
Revolving Loans Converted to Term	0	1,441,000
Total loans and leases	29,288,000	35,196,000
Credit Quality Grades 7-12 | Commercial real estate
Loan and Lease Financings
Financing receivable originated during current fiscal year	678,000	1,532,000
Financing receivable originated one year prior to current fiscal year	5,313,000	1,716,000
Financing receivable originated two years prior to current fiscal year	2,576,000	7,824,000
Financing receivable originated three years prior to current fiscal year	651,000	5,789,000
Financing receivable originated four years prior to current fiscal year	4,372,000	47,000
Financing receivable originated five years or more prior to current fiscal year	1,017,000	1,070,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	14,607,000	17,978,000
Performing | Residential real estate and home equity
Loan and Lease Financings
Financing receivable originated during current fiscal year	87,767,000	115,154,000
Financing receivable originated one year prior to current fiscal year	110,058,000	100,690,000
Financing receivable originated two years prior to current fiscal year	89,458,000	97,205,000
Financing receivable originated three years prior to current fiscal year	88,232,000	34,498,000
Financing receivable originated four years prior to current fiscal year	30,681,000	6,864,000
Financing receivable originated five years or more prior to current fiscal year	72,211,000	81,653,000
Revolving Loans	152,037,000	142,724,000
Revolving Loans Converted to Term	5,575,000	4,115,000
Total loans and leases	636,019,000	582,903,000
Performing | Consumer
Loan and Lease Financings
Financing receivable originated during current fiscal year	53,023,000	74,258,000
Financing receivable originated one year prior to current fiscal year	47,789,000	34,619,000
Financing receivable originated two years prior to current fiscal year	19,739,000	12,924,000
Financing receivable originated three years prior to current fiscal year	6,286,000	7,375,000
Financing receivable originated four years prior to current fiscal year	2,539,000	2,977,000
Financing receivable originated five years or more prior to current fiscal year	1,021,000	692,000
Revolving Loans	12,063,000	18,098,000
Revolving Loans Converted to Term	0	0
Total loans and leases	142,460,000	150,943,000
Nonperforming | Residential real estate and home equity
Loan and Lease Financings
Financing receivable originated during current fiscal year	0	0
Financing receivable originated one year prior to current fiscal year	107,000	131,000
Financing receivable originated two years prior to current fiscal year	74,000	693,000
Financing receivable originated three years prior to current fiscal year	0	0
Financing receivable originated four years prior to current fiscal year	414,000	0
Financing receivable originated five years or more prior to current fiscal year	756,000	725,000
Revolving Loans	536,000	180,000
Revolving Loans Converted to Term	67,000	105,000
Total loans and leases	1,954,000	1,834,000
Nonperforming | Consumer
Loan and Lease Financings
Financing receivable originated during current fiscal year	63,000	148,000
Financing receivable originated one year prior to current fiscal year	246,000	65,000
Financing receivable originated two years prior to current fiscal year	123,000	49,000
Financing receivable originated three years prior to current fiscal year	31,000	53,000
Financing receivable originated four years prior to current fiscal year	28,000	12,000
Financing receivable originated five years or more prior to current fiscal year	6,000	12,000
Revolving Loans	0	0
Revolving Loans Converted to Term	0	0
Total loans and leases	$ 497,000	$ 339,000