Loans, Credit Risk Profile Based on Rating Category and Payment Activity and on Performing and Nonperforming Status, Segregated by Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile	$ 3,287,541	$ 3,248,664
Consumer mortgage loans secured by real estate properties for which formal foreclosure proceedings are in process	3,100	2,400
Commercial [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	106,662
2019	316,027
2018	227,701
2017	211,924
2016	199,000
Prior	389,643
Revolving Loans	225,986
Total	1,676,943
Loan portfolio based on credit risk profile	1,676,943	1,664,948
Commercial [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	102,639
2019	298,688
2018	216,213
2017	200,876
2016	182,430
Prior	356,284
Revolving Loans	225,358
Total	$ 1,582,488
Loan portfolio based on credit risk profile		1,493,359
Commercial [Member] | Pass [Member] | Minimum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Review period for loans	12 months
Commercial [Member] | Pass [Member] | Maximum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Review period for loans	18 months
Commercial [Member] | Special Mention[Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	$ 0
2019	3,519
2018	5,766
2017	1,257
2016	931
Prior	3,415
Revolving Loans	20
Total	14,908
Commercial [Member] | Watch [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		71,551
Commercial [Member] | OAEM [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		34,283
Commercial [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	4,023
2019	13,820
2018	5,722
2017	9,791
2016	15,639
Prior	29,913
Revolving Loans	552
Total	79,460
Loan portfolio based on credit risk profile		65,663
Commercial [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	31
Revolving Loans	56
Total	87
Loan portfolio based on credit risk profile		92
Commercial [Member] | Hotel/Motel [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	8,621
2019	71,038
2018	41,191
2017	54,375
2016	32,742
Prior	40,676
Revolving Loans	74
Total	248,717
Loan portfolio based on credit risk profile	248,717
Commercial [Member] | Hotel/Motel [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	8,621
2019	71,038
2018	41,059
2017	53,262
2016	23,743
Prior	35,479
Revolving Loans	74
Total	233,276
Commercial [Member] | Hotel/Motel [Member] | Special Mention[Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Total	0
Commercial [Member] | Hotel/Motel [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	132
2017	1,113
2016	8,999
Prior	5,197
Revolving Loans	0
Total	15,441
Commercial [Member] | Hotel/Motel [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Total	0
Commercial [Member] | Commercial Real Estate Residential [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	15,223
2019	54,387
2018	39,683
2017	30,673
2016	36,276
Prior	73,610
Revolving Loans	12,213
Total	262,065
Loan portfolio based on credit risk profile	262,065
Commercial [Member] | Commercial Real Estate Residential [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	14,777
2019	49,003
2018	35,510
2017	25,537
2016	34,625
Prior	69,673
Revolving Loans	12,213
Total	241,338
Commercial [Member] | Commercial Real Estate Residential [Member] | Special Mention[Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	3,102
2018	633
2017	967
2016	451
Prior	61
Revolving Loans	0
Total	5,214
Commercial [Member] | Commercial Real Estate Residential [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	446
2019	2,282
2018	3,540
2017	4,169
2016	1,200
Prior	3,876
Revolving Loans	0
Total	15,513
Commercial [Member] | Commercial Real Estate Residential [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Total	0
Commercial [Member] | Commercial Real Estate Nonresidential [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	36,901
2019	136,535
2018	101,363
2017	106,031
2016	115,806
Prior	244,295
Revolving Loans	30,756
Total	771,687
Loan portfolio based on credit risk profile	771,687
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	35,164
2019	128,993
2018	99,550
2017	102,018
2016	113,817
Prior	220,958
Revolving Loans	30,277
Total	730,777
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | Special Mention[Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	417
2018	71
2017	5
2016	0
Prior	3,303
Revolving Loans	20
Total	3,816
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	1,737
2019	7,125
2018	1,742
2017	4,008
2016	1,989
Prior	20,003
Revolving Loans	459
Total	37,063
Commercial [Member] | Commercial Real Estate Nonresidential [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	31
Revolving Loans	0
Total	31
Commercial [Member] | Dealer Floorplans [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	80,828
Total	80,828
Loan portfolio based on credit risk profile	80,828
Commercial [Member] | Dealer Floorplans [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	80,772
Total	80,772
Commercial [Member] | Dealer Floorplans [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Total	0
Commercial [Member] | Dealer Floorplans [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	56
Total	56
Commercial [Member] | Commercial Other [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	45,917
2019	54,067
2018	45,464
2017	20,845
2016	14,176
Prior	31,062
Revolving Loans	102,115
Total	313,646
Loan portfolio based on credit risk profile	313,646	389,683
Commercial [Member] | Commercial Other [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	44,077
2019	49,654
2018	40,094
2017	20,059
2016	10,245
Prior	30,174
Revolving Loans	102,022
Total	296,325
Loan portfolio based on credit risk profile		358,203
Commercial [Member] | Commercial Other [Member] | Special Mention[Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	5,062
2017	285
2016	480
Prior	51
Revolving Loans	0
Total	5,878
Commercial [Member] | Commercial Other [Member] | Watch [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		13,618
Commercial [Member] | Commercial Other [Member] | OAEM [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		6,065
Commercial [Member] | Commercial Other [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	1,840
2019	4,413
2018	308
2017	501
2016	3,451
Prior	837
Revolving Loans	93
Total	11,443
Loan portfolio based on credit risk profile		11,737
Commercial [Member] | Commercial Other [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Total	0
Loan portfolio based on credit risk profile		60
Commercial [Member] | Construction [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		104,809
Commercial [Member] | Construction [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		98,102
Commercial [Member] | Construction [Member] | Watch [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		3,595
Commercial [Member] | Construction [Member] | OAEM [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		254
Commercial [Member] | Construction [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		2,858
Commercial [Member] | Construction [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		0
Commercial [Member] | Real Estate Mortgage [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		1,169,975
Commercial [Member] | Real Estate Mortgage [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		1,036,573
Commercial [Member] | Real Estate Mortgage [Member] | Watch [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		54,338
Commercial [Member] | Real Estate Mortgage [Member] | OAEM [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		27,964
Commercial [Member] | Real Estate Mortgage [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		51,068
Commercial [Member] | Real Estate Mortgage [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		32
Commercial [Member] | Equipment Leases [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		481
Commercial [Member] | Equipment Leases [Member] | Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		481
Commercial [Member] | Equipment Leases [Member] | Watch [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		0
Commercial [Member] | Equipment Leases [Member] | OAEM [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		0
Commercial [Member] | Equipment Leases [Member] | Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		0
Commercial [Member] | Equipment Leases [Member] | Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		0
Residential [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	35,151
2019	161,821
2018	95,450
2017	89,151
2016	70,966
Prior	358,780
Revolving Loans	99,409
Total	910,728
Loan portfolio based on credit risk profile	910,728
Residential [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	35,151
2019	161,473
2018	94,854
2017	88,911
2016	70,457
Prior	349,694
Revolving Loans	98,984
Total	899,524
Residential [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	348
2018	596
2017	240
2016	509
Prior	9,086
Revolving Loans	425
Total	11,204
Residential [Member] | Construction [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		63,350
Residential [Member] | Construction [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		62,716
Residential [Member] | Construction [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		634
Residential [Member] | Real Estate Mortgage [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	35,151
2019	161,735
2018	95,450
2017	89,151
2016	70,958
Prior	346,446
Revolving Loans	0
Total	798,891
Loan portfolio based on credit risk profile	798,891	733,003
Residential [Member] | Real Estate Mortgage [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	35,151
2019	161,387
2018	94,854
2017	88,911
2016	70,449
Prior	338,123
Revolving Loans	0
Total	788,875
Loan portfolio based on credit risk profile		721,094
Residential [Member] | Real Estate Mortgage [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	348
2018	596
2017	240
2016	509
Prior	8,323
Revolving Loans	0
Total	10,016
Loan portfolio based on credit risk profile		11,909
Residential [Member] | Home Equity Lines [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	86
2018	0
2017	0
2016	8
Prior	12,334
Revolving Loans	99,409
Total	111,837
Loan portfolio based on credit risk profile	111,837	111,894
Residential [Member] | Home Equity Lines [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	86
2018	0
2017	0
2016	8
Prior	11,571
Revolving Loans	98,984
Total	110,649
Loan portfolio based on credit risk profile		110,834
Residential [Member] | Home Equity Lines [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	763
Revolving Loans	425
Total	1,188
Loan portfolio based on credit risk profile		1,060
Consumer [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	100,809
2019	233,595
2018	175,536
2017	96,468
2016	52,333
Prior	41,129
Revolving Loans	0
Total	699,870
Loan portfolio based on credit risk profile	699,870
Consumer [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	100,809
2019	233,399
2018	175,416
2017	96,359
2016	52,297
Prior	41,087
Revolving Loans	0
Total	699,367
Consumer [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	196
2018	120
2017	109
2016	36
Prior	42
Revolving Loans	0
Total	503
Consumer [Member] | Consumer Direct [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	15,792
2019	54,038
2018	29,932
2017	16,363
2016	10,197
Prior	19,081
Revolving Loans	0
Total	145,403
Loan portfolio based on credit risk profile	145,403	148,051
Consumer [Member] | Consumer Direct [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	15,792
2019	54,032
2018	29,905
2017	16,359
2016	10,196
Prior	19,081
Revolving Loans	0
Total	145,365
Loan portfolio based on credit risk profile		147,954
Consumer [Member] | Consumer Direct [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	6
2018	27
2017	4
2016	1
Prior	0
Revolving Loans	0
Total	38
Loan portfolio based on credit risk profile		97
Consumer [Member] | Consumer Indirect [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	85,017
2019	179,557
2018	145,604
2017	80,105
2016	42,136
Prior	22,048
Revolving Loans	0
Total	554,467
Loan portfolio based on credit risk profile	554,467	527,418
Consumer [Member] | Consumer Indirect [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	85,017
2019	179,367
2018	145,511
2017	80,000
2016	42,101
Prior	22,006
Revolving Loans	0
Total	554,002
Loan portfolio based on credit risk profile		526,970
Consumer [Member] | Consumer Indirect [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2020	0
2019	190
2018	93
2017	105
2016	35
Prior	42
Revolving Loans	0
Total	$ 465
Loan portfolio based on credit risk profile		448
Residential and Consumer Portfolio Segments [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		1,583,716
Residential and Consumer Portfolio Segments [Member] | Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		1,569,568
Residential and Consumer Portfolio Segments [Member] | Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loan portfolio based on credit risk profile		$ 14,148