Loan and Lease Financings (Details 2)	12 Months Ended
	Dec. 31, 2020 USD ($) method class	Dec. 31, 2019 USD ($)
Receivables [Abstract]
Number of methods to assess credit risk | method	2
Loan and Lease Financings
Amortized cost of loans and leases	$ 5,489,301,000	$ 5,085,527,000
Number of domestic aircraft loan pools | class	2
Commercial and agricultural
Loan and Lease Financings
2020	$ 673,693,000
2019	195,254,000
2018	139,137,000
2017	96,423,000
2016	27,234,000
Prior	21,924,000
Revolving Loans	325,057,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	$ 1,478,722,000	1,132,791,000
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
Auto and light truck
Loan and Lease Financings
2020	$ 268,045,000
2019	168,977,000
2018	65,545,000
2017	32,713,000
2016	6,460,000
Prior	629,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	$ 542,369,000	588,807,000
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
2020	$ 92,698,000
2019	89,292,000
2018	44,205,000
2017	31,773,000
2016	16,276,000
Prior	4,928,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	$ 279,172,000	294,824,000
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
2020	$ 440,802,000
2019	155,919,000
2018	93,521,000
2017	96,053,000
2016	46,159,000
Prior	22,636,000
Revolving Loans	6,370,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	$ 861,460,000
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
2020	$ 328,692,000
2019	194,293,000
2018	106,962,000
2017	43,111,000
2016	12,861,000
Prior	5,807,000
Revolving Loans	20,490,000
Revolving Loans Converted to Term	2,672,000
Amortized cost of loans and leases	714,888,000	705,451,000
Commercial real estate
Loan and Lease Financings
2020	200,243,000
2019	212,467,000
2018	179,020,000
2017	181,693,000
2016	70,784,000
Prior	125,284,000
Revolving Loans	373,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	969,864,000	908,177,000
Residential real estate and home equity
Loan and Lease Financings
2020	133,829,000
2019	65,690,000
2018	18,215,000
2017	22,943,000
2016	41,847,000
Prior	87,541,000
Revolving Loans	135,502,000
Revolving Loans Converted to Term	5,812,000
Amortized cost of loans and leases	511,379,000	532,003,000
Consumer
Loan and Lease Financings
2020	43,826,000
2019	34,508,000
2018	18,982,000
2017	7,041,000
2016	2,267,000
Prior	795,000
Revolving Loans	24,028,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	131,447,000	$ 139,434,000
Credit Quality Grades 1-6 | Commercial and agricultural
Loan and Lease Financings
2020	666,905,000
2019	193,555,000
2018	134,411,000
2017	92,916,000
2016	26,034,000
Prior	19,790,000
Revolving Loans	291,990,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	1,425,601,000
Credit Quality Grades 1-6 | Auto and light truck
Loan and Lease Financings
2020	248,932,000
2019	141,841,000
2018	52,749,000
2017	24,101,000
2016	4,210,000
Prior	608,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	472,441,000
Credit Quality Grades 1-6 | Medium and heavy duty truck
Loan and Lease Financings
2020	92,698,000
2019	88,314,000
2018	44,205,000
2017	31,773,000
2016	15,644,000
Prior	4,840,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	277,474,000
Credit Quality Grades 1-6 | Aircraft
Loan and Lease Financings
2020	429,283,000
2019	153,358,000
2018	93,042,000
2017	95,457,000
2016	43,972,000
Prior	20,966,000
Revolving Loans	6,370,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	842,448,000
Credit Quality Grades 1-6 | Construction equipment
Loan and Lease Financings
2020	311,174,000
2019	180,550,000
2018	96,320,000
2017	42,713,000
2016	12,624,000
Prior	5,722,000
Revolving Loans	17,502,000
Revolving Loans Converted to Term	737,000
Amortized cost of loans and leases	667,342,000
Credit Quality Grades 1-6 | Commercial real estate
Loan and Lease Financings
2020	190,725,000
2019	204,477,000
2018	173,847,000
2017	175,009,000
2016	69,022,000
Prior	122,762,000
Revolving Loans	373,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	936,215,000
Credit Quality Grades 7-12
Loan and Lease Financings
Threshold value of loan or lease for evaluation of the appropriateness of the impairment reserve	100,000
Credit Quality Grades 7-12 | Commercial and agricultural
Loan and Lease Financings
2020	6,788,000
2019	1,699,000
2018	4,726,000
2017	3,507,000
2016	1,200,000
Prior	2,134,000
Revolving Loans	33,067,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	53,121,000
Credit Quality Grades 7-12 | Auto and light truck
Loan and Lease Financings
2020	19,113,000
2019	27,136,000
2018	12,796,000
2017	8,612,000
2016	2,250,000
Prior	21,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	69,928,000
Credit Quality Grades 7-12 | Medium and heavy duty truck
Loan and Lease Financings
2020	0
2019	978,000
2018	0
2017	0
2016	632,000
Prior	88,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	1,698,000
Credit Quality Grades 7-12 | Aircraft
Loan and Lease Financings
2020	11,519,000
2019	2,561,000
2018	479,000
2017	596,000
2016	2,187,000
Prior	1,670,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	19,012,000
Credit Quality Grades 7-12 | Construction equipment
Loan and Lease Financings
2020	17,518,000
2019	13,743,000
2018	10,642,000
2017	398,000
2016	237,000
Prior	85,000
Revolving Loans	2,988,000
Revolving Loans Converted to Term	1,935,000
Amortized cost of loans and leases	47,546,000
Credit Quality Grades 7-12 | Commercial real estate
Loan and Lease Financings
2020	9,518,000
2019	7,990,000
2018	5,173,000
2017	6,684,000
2016	1,762,000
Prior	2,522,000
Revolving Loans	0
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	33,649,000
Performing | Residential real estate and home equity
Loan and Lease Financings
2020	133,829,000
2019	65,690,000
2018	18,194,000
2017	22,929,000
2016	41,847,000
Prior	86,106,000
Revolving Loans	135,255,000
Revolving Loans Converted to Term	5,703,000
Amortized cost of loans and leases	509,553,000
Performing | Consumer
Loan and Lease Financings
2020	43,824,000
2019	34,409,000
2018	18,904,000
2017	7,005,000
2016	2,259,000
Prior	793,000
Revolving Loans	23,869,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	131,063,000
Nonperforming | Residential real estate and home equity
Loan and Lease Financings
2020	0
2019	0
2018	21,000
2017	14,000
2016	0
Prior	1,435,000
Revolving Loans	247,000
Revolving Loans Converted to Term	109,000
Amortized cost of loans and leases	1,826,000
Nonperforming | Consumer
Loan and Lease Financings
2020	2,000
2019	99,000
2018	78,000
2017	36,000
2016	8,000
Prior	2,000
Revolving Loans	159,000
Revolving Loans Converted to Term	0
Amortized cost of loans and leases	$ 384,000