Loans, Balance in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2020
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 48,022		$ 35,096	$ 35,096
Provision charged to expense	(2,499)	$ 1,000	12,707	16,047
Losses charged off	(1,470)		(2,415)	(10,453)
Recoveries	1,293		1,017	4,292
Ending balance	45,346	48,022	49,445	48,022
Commercial [Member] \| Hotel/Motel [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	6,356		3,371	3,371
Provision charged to expense	308		2,381	2,858
Losses charged off	0		0	(43)
Recoveries	0		0	0
Ending balance	6,664	6,356	5,922	6,356
Commercial [Member] \| Commercial Real Estate Residential [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	4,464		3,439	3,439
Provision charged to expense	199		1,337	1,772
Losses charged off	(24)		(51)	(182)
Recoveries	2		8	156
Ending balance	4,641	4,464	4,012	4,464
Commercial [Member] \| Commercial Real Estate Nonresidential [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	11,086		8,515	8,515
Provision charged to expense	(135)		2,984	3,303
Losses charged off	(151)		(59)	(941)
Recoveries	13		4	90
Ending balance	10,813	11,086	11,563	11,086
Commercial [Member] \| Dealer Floorplans [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,382		802	802
Provision charged to expense	(64)		91	(214)
Losses charged off	0		0	(26)
Recoveries	0		0	0
Ending balance	1,318	1,382	1,713	1,382
Commercial [Member] \| Commercial Other [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	4,289		5,556	5,556
Provision charged to expense	269		1,434	2,040
Losses charged off	(112)		(359)	(3,339)
Recoveries	125		169	423
Ending balance	4,571	4,289	6,409	4,289
Residential [Member] \| Real Estate Mortgage [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	7,832		4,604	4,604
Provision charged to expense	(690)		1,099	1,584
Losses charged off	(8)		(60)	(321)
Recoveries	9		7	72
Ending balance	7,143	7,832	7,543	7,832
Residential [Member] \| Home Equity Lines [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	844		897	897
Provision charged to expense	(93)		67	16
Losses charged off	(5)		0	(4)
Recoveries	4		1	10
Ending balance	750	844	890	844
Consumer [Member] \| Consumer Direct [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,863		1,711	1,711
Provision charged to expense	(14)		739	609
Losses charged off	(154)		(369)	(927)
Recoveries	116		122	510
Ending balance	1,811	1,863	2,163	1,863
Consumer [Member] \| Consumer Indirect [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance	9,906		6,201	6,201
Provision charged to expense	(2,279)		2,575	4,079
Losses charged off	(1,016)		(1,517)	(4,670)
Recoveries	1,024		706	3,031
Ending balance	$ 7,635	$ 9,906	9,230	9,906
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			3,040	3,040
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Commercial [Member] \| Hotel/Motel [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			170	170
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Commercial [Member] \| Commercial Real Estate Residential [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			(721)	(721)
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Commercial [Member] \| Commercial Real Estate Nonresidential [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			119	119
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Commercial [Member] \| Dealer Floorplans [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			820	820
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Commercial [Member] \| Commercial Other [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			(391)	(391)
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Residential [Member] \| Real Estate Mortgage [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			1,893	1,893
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Residential [Member] \| Home Equity Lines [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			(75)	(75)
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Consumer [Member] \| Consumer Direct [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			(40)	(40)
Cumulative Effect, Period of Adoption, Adjustment [Member] \| ASU 2016-13 [Member] \| Consumer [Member] \| Consumer Indirect [Member]
Allowance for Credit Losses [Roll Forward]
Beginning balance			$ 1,265	$ 1,265

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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