Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Allowance for loan losses [Roll Forward]
Beginning balance	$ 37,133	$ 35,697	$ 35,933	$ 36,094	$ 36,094
Provision charged to expense	666	2,191	4,659	5,829	7,872
Losses charged off	(2,443)	(2,962)	(7,123)	(8,729)	(11,668)
Recoveries	1,035	875	2,922	2,607	3,635
Ending balance	36,391	35,801	36,391	35,801	35,933
Ending balance [Abstract]
Individually evaluated for impairment	1,391	1,149	1,391	1,149	1,313
Collectively evaluated for impairment	35,000	34,652	35,000	34,652	34,620
Loans ending balance [Abstract]
Individually evaluated for impairment	46,199	55,045	46,199	55,045	52,202
Collectively evaluated for impairment	3,067,222	2,876,254	3,067,222	2,876,254	2,886,169
Commercial [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	669	1,437	884	2,199	2,199
Provision charged to expense	(19)	54	(239)	(701)	(1,035)
Losses charged off	(6)	(79)	(10)	(94)	(316)
Recoveries	28	18	37	26	36
Ending balance	672	1,430	672	1,430	884
Ending balance [Abstract]
Individually evaluated for impairment	25	212	25	212	213
Collectively evaluated for impairment	647	1,218	647	1,218	671
Loans ending balance [Abstract]
Individually evaluated for impairment	4,766	5,938	4,766	5,938	5,609
Collectively evaluated for impairment	69,516	62,337	69,516	62,337	61,389
Commercial [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	15,299	14,438	14,191	14,434	14,434
Provision charged to expense	(1)	585	1,622	1,726	1,220
Losses charged off	(249)	(319)	(776)	(1,505)	(1,641)
Recoveries	53	78	65	127	178
Ending balance	15,102	14,782	15,102	14,782	14,191
Ending balance [Abstract]
Individually evaluated for impairment	1,301	747	1,301	747	1,035
Collectively evaluated for impairment	13,801	14,035	13,801	14,035	13,156
Loans ending balance [Abstract]
Individually evaluated for impairment	29,240	35,848	29,240	35,848	33,756
Collectively evaluated for impairment	1,168,364	1,047,792	1,168,364	1,047,792	1,051,672
Commercial [Member] | Equipment Lease Financing [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	33	94	42	79	79
Provision charged to expense	(14)	(28)	(23)	(13)	(37)
Losses charged off	0	0	0	0	0
Recoveries	0	0	0	0	0
Ending balance	19	66	19	66	42
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	19	66	19	66	42
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	3,290	6,242	3,290	6,242	5,512
Commercial [Member] | Other [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,993	4,430	4,656	4,225	4,225
Provision charged to expense	210	185	1,229	1,156	2,128
Losses charged off	(549)	(622)	(1,386)	(1,667)	(2,136)
Recoveries	308	92	463	371	439
Ending balance	4,962	4,085	4,962	4,085	4,656
Ending balance [Abstract]
Individually evaluated for impairment	65	190	65	190	65
Collectively evaluated for impairment	4,897	3,895	4,897	3,895	4,591
Loans ending balance [Abstract]
Individually evaluated for impairment	10,124	11,770	10,124	11,770	11,354
Collectively evaluated for impairment	329,213	343,214	329,213	343,214	338,805
Residential [Member] | Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	581	558	629	550	550
Provision charged to expense	49	8	0	144	264
Losses charged off	0	(61)	0	(192)	(192)
Recoveries	0	4	1	7	7
Ending balance	630	509	630	509	629
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	630	509	630	509	629
Loans ending balance [Abstract]
Individually evaluated for impairment	873	0	873	0	0
Collectively evaluated for impairment	63,568	55,412	63,568	55,412	57,966
Residential [Member] | Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	5,662	6,372	6,027	6,678	6,678
Provision charged to expense	276	330	1	440	291
Losses charged off	(158)	(366)	(321)	(849)	(1,043)
Recoveries	6	8	79	75	101
Ending balance	5,786	6,344	5,786	6,344	6,027
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	5,786	6,344	5,786	6,344	6,027
Loans ending balance [Abstract]
Individually evaluated for impairment	1,196	1,489	1,196	1,489	1,483
Collectively evaluated for impairment	711,041	704,539	711,041	704,539	701,486
Residential [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	747	819	774	839	839
Provision charged to expense	113	3	87	(1)	(20)
Losses charged off	(53)	0	(57)	(21)	(54)
Recoveries	0	2	3	7	9
Ending balance	807	824	807	824	774
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	807	824	807	824	774
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	96,755	89,467	96,755	89,467	91,511
Consumer [Member] | Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	1,866	1,634	1,885	1,594	1,594
Provision charged to expense	47	170	243	669	912
Losses charged off	(166)	(204)	(675)	(893)	(1,236)
Recoveries	110	111	404	341	615
Ending balance	1,857	1,711	1,857	1,711	1,885
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	1,857	1,711	1,857	1,711	1,885
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	137,657	131,815	137,657	131,815	133,093
Consumer [Member] | Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	7,283	5,915	6,845	5,496	5,496
Provision charged to expense	5	884	1,739	2,409	4,149
Losses charged off	(1,262)	(1,311)	(3,898)	(3,508)	(5,050)
Recoveries	530	562	1,870	1,653	2,250
Ending balance	6,556	6,050	6,556	6,050	6,845
Ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	6,556	6,050	6,556	6,050	6,845
Loans ending balance [Abstract]
Individually evaluated for impairment	0	0	0	0	0
Collectively evaluated for impairment	$ 487,818	$ 435,436	$ 487,818	$ 435,436	$ 444,735