Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Allowance for loan losses [Roll Forward]
Beginning balance	$ 35,908	$ 36,151	$ 36,151
Provision charged to expense	190	946	6,167
Losses charged off	(2,055)	(2,977)	(10,998)
Recoveries	961	1,069	4,588
Ending balance	35,004	35,189	35,908
Ending balance [Abstract]
Individually evaluated for impairment	1,631	739	801
Collectively evaluated for impairment	33,373	34,450	35,107
Loans ending balance [Abstract]
Individually evaluated for impairment	50,355	48,185	46,366
Collectively evaluated for impairment	3,139,377	3,070,056	3,162,272
Commercial [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	862	686	686
Provision charged to expense	38	(14)	115
Losses charged off	0	0	0
Recoveries	3	14	61
Ending balance	903	686	862
Ending balance [Abstract]
Individually evaluated for impairment	164	0	50
Collectively evaluated for impairment	739	686	812
Loans ending balance [Abstract]
Individually evaluated for impairment	3,632	4,009	4,227
Collectively evaluated for impairment	71,732	74,638	78,488
Commercial [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	14,531	14,509	14,509
Provision charged to expense	287	(191)	786
Losses charged off	(35)	(210)	(988)
Recoveries	17	25	224
Ending balance	14,800	14,133	14,531
Ending balance [Abstract]
Individually evaluated for impairment	847	739	605
Collectively evaluated for impairment	13,953	13,394	13,926
Loans ending balance [Abstract]
Individually evaluated for impairment	34,329	33,389	31,499
Collectively evaluated for impairment	1,148,475	1,158,239	1,151,594
Commercial [Member] | Equipment Lease Financing [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	12	18	18
Provision charged to expense	(2)	5	(6)
Losses charged off	0	0	0
Recoveries	0	0	0
Ending balance	10	23	12
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	10	23	12
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,354	2,683	1,740
Commercial [Member] | Other [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,993	5,039	5,039
Provision charged to expense	382	(651)	824
Losses charged off	(242)	(236)	(1,513)
Recoveries	84	77	643
Ending balance	5,217	4,229	4,993
Ending balance [Abstract]
Individually evaluated for impairment	620	0	146
Collectively evaluated for impairment	4,597	4,229	4,847
Loans ending balance [Abstract]
Individually evaluated for impairment	10,057	9,183	8,758
Collectively evaluated for impairment	378,003	329,452	368,440
Residential [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	512	660	660
Provision charged to expense	(116)	(4)	(115)
Losses charged off	0	(23)	(33)
Recoveries	0	0	0
Ending balance	396	633	512
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	396	633	512
Loans ending balance [Abstract]
Individually evaluated for impairment	0	318	0
Collectively evaluated for impairment	54,013	63,575	57,160
Residential [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,433	5,688	5,688
Provision charged to expense	(278)	435	(336)
Losses charged off	(120)	(193)	(1,004)
Recoveries	18	6	85
Ending balance	4,053	5,936	4,433
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	4,053	5,936	4,433
Loans ending balance [Abstract]
Individually evaluated for impairment	2,337	1,286	1,882
Collectively evaluated for impairment	717,955	717,472	720,535
Residential [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	841	857	857
Provision charged to expense	84	5	39
Losses charged off	(25)	(1)	(69)
Recoveries	1	1	14
Ending balance	901	862	841
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	901	862	841
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	108,018	99,593	106,299
Consumer [Member] | Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	1,883	1,863	1,863
Provision charged to expense	(119)	80	572
Losses charged off	(246)	(216)	(997)
Recoveries	117	71	445
Ending balance	1,635	1,798	1,883
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,635	1,798	1,883
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	141,855	136,576	144,289
Consumer [Member] | Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	7,841	6,831	6,831
Provision charged to expense	(86)	1,281	4,288
Losses charged off	(1,387)	(2,098)	(6,394)
Recoveries	721	875	3,116
Ending balance	7,089	6,889	7,841
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	7,089	6,889	7,841
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	$ 517,972	$ 487,828	$ 533,727