Loans and Leases - Allowance for Loan and Leases Losses Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	$ 20,616	$ 17,662	$ 19,426	$ 17,525
Charge-offs	(1,379)	(1,477)	(4,221)	(2,431)
Recoveries	318	76	614	137
Provision for loan and lease losses	1,627	3,137	5,363	4,167
Balance	21,182	19,398	21,182	19,398
Commercial mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	8,241	7,174	7,567	7,550
Charge-offs	0	(16)	(1,387)	(16)
Recoveries	3	3	17	6
Provision for loan and lease losses	714	872	2,761	493
Balance	8,958	8,033	8,958	8,033
Home equity loans and lines
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	1,038	1,045	1,003	1,086
Charge-offs	(267)	(200)	(314)	(225)
Recoveries	87	1	87	1
Provision for loan and lease losses	185	87	267	71
Balance	1,043	933	1,043	933
Residential mortgage
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	1,891	1,898	1,813	1,926
Charge-offs	(341)	0	(671)	0
Recoveries	2	1	3	1
Provision for loan and lease losses	341	34	748	6
Balance	1,893	1,933	1,893	1,933
Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	1,186	844	1,485	937
Charge-offs	0	0	0	0
Recoveries	1	1	2	2
Provision for loan and lease losses	(101)	313	(401)	219
Balance	1,086	1,158	1,086	1,158
Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	5,888	5,361	5,461	5,038
Charge-offs	(21)	(467)	(426)	(750)
Recoveries	39	0	54	1
Provision for loan and lease losses	(206)	778	611	1,383
Balance	5,700	5,672	5,700	5,672
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	328	291	229	246
Charge-offs	(126)	(43)	(231)	(92)
Recoveries	7	2	18	3
Provision for loan and lease losses	44	39	237	132
Balance	253	289	253	289
Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance	2,044	1,049	1,868	742
Charge-offs	(624)	(751)	(1,192)	(1,348)
Recoveries	179	68	433	123
Provision for loan and lease losses	650	1,014	1,140	1,863
Balance	$ 2,249	$ 1,380	$ 2,249	$ 1,380