Allowance for Credit Losses (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) item	Mar. 31, 2022 USD ($)
Allowance for credit losses
Number of classes existing in loan and lease portfolio | item	9
Changes in allowance for loan and lease losses
Balance at the beginning of the period	$ 139,268	$ 127,492
Financing Receivable, Allowance for Credit Loss, Writeoff	1,041	217
Recoveries	1,235	451
Net charge-offs (recoveries)	(194)	(234)
Provision (recovery of provision)	3,049	2,233
Balance at the end of the period	142,511	129,959
Commercial and agricultural
Changes in allowance for loan and lease losses
Balance at the beginning of the period	14,635	15,409
Financing Receivable, Allowance for Credit Loss, Writeoff	564	0
Recoveries	172	4
Net charge-offs (recoveries)	392	(4)
Provision (recovery of provision)	1,844	185
Balance at the end of the period	16,087	15,598
Solar
Changes in allowance for loan and lease losses
Balance at the beginning of the period	7,217	6,585
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Provision (recovery of provision)	(929)	(168)
Balance at the end of the period	6,288	6,417
Auto and light truck
Changes in allowance for loan and lease losses
Balance at the beginning of the period	18,634	19,624
Financing Receivable, Allowance for Credit Loss, Writeoff	112	0
Recoveries	541	65
Net charge-offs (recoveries)	(429)	(65)
Provision (recovery of provision)	(505)	(168)
Balance at the end of the period	18,558	19,521
Medium and heavy duty truck
Changes in allowance for loan and lease losses
Balance at the beginning of the period	7,566	6,015
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Provision (recovery of provision)	263	34
Balance at the end of the period	7,829	6,049
Aircraft
Changes in allowance for loan and lease losses
Balance at the beginning of the period	41,093	33,628
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0
Recoveries	226	316
Net charge-offs (recoveries)	(226)	(316)
Provision (recovery of provision)	(1,186)	2,024
Balance at the end of the period	40,133	35,968
Construction equipment
Changes in allowance for loan and lease losses
Balance at the beginning of the period	24,039	19,673
Financing Receivable, Allowance for Credit Loss, Writeoff	1	48
Recoveries	0	0
Net charge-offs (recoveries)	1	48
Provision (recovery of provision)	1,541	416
Balance at the end of the period	25,579	20,041
Commercial real estate
Changes in allowance for loan and lease losses
Balance at the beginning of the period	17,431	19,691
Financing Receivable, Allowance for Credit Loss, Writeoff	39	0
Recoveries	3	0
Net charge-offs (recoveries)	36	0
Provision (recovery of provision)	1,905	(445)
Balance at the end of the period	19,300	19,246
Residential real estate and home equity
Changes in allowance for loan and lease losses
Balance at the beginning of the period	6,478	5,084
Financing Receivable, Allowance for Credit Loss, Writeoff	1	4
Recoveries	233	1
Net charge-offs (recoveries)	(232)	3
Provision (recovery of provision)	(89)	137
Balance at the end of the period	6,621	5,218
Consumer
Changes in allowance for loan and lease losses
Balance at the beginning of the period	2,175	1,783
Financing Receivable, Allowance for Credit Loss, Writeoff	324	165
Recoveries	60	65
Net charge-offs (recoveries)	264	100
Provision (recovery of provision)	205	218
Balance at the end of the period	$ 2,116	$ 1,901