Loans and Leases - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	$ 3,523,514	$ 3,427,154
Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	3,032,270	2,885,251
Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	3,457,614	3,374,840
Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,994,133	2,856,184
Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	463,481	518,656
Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	14,089	4,306
Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	7,614	4,080
Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	6,475	226
Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	51,405	46,909
Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	30,523	24,986
Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	20,882	21,923
Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	406	1,099
Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	1
Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	406	1,098
Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	3,523,514	3,427,154
Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	3,032,270	2,885,251
Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	491,244	541,903
Commercial mortgage
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,746,695	1,657,436
Commercial mortgage | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,436,611	1,327,822
Commercial mortgage | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,714,426	1,635,068
Commercial mortgage | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,428,214	1,321,973
Commercial mortgage | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	286,212	313,095
Commercial mortgage | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	10,571	631
Commercial mortgage | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	4,325	631
Commercial mortgage | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	6,246	0
Commercial mortgage | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	21,292	20,639
Commercial mortgage | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	4,072	5,218
Commercial mortgage | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	17,220	15,421
Commercial mortgage | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	406	1,098
Commercial mortgage | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Commercial mortgage | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	406	1,098
Commercial mortgage | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,746,695	1,657,436
Commercial mortgage | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	1,436,611	1,327,822
Commercial mortgage | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	310,084	329,614
Construction
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	159,761	181,078
Construction | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	157,572	174,592
Construction | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	152,120	171,353
Construction | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	149,931	167,272
Construction | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,189	4,081
Construction | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	937	938
Construction | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	937	938
Construction | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Construction | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	6,704	8,787
Construction | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	6,704	6,382
Construction | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	2,405
Construction | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Construction | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Construction | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Construction | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	159,761	181,078
Construction | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	157,572	174,592
Construction | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,189	6,486
Real estate loans
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,613,626	2,540,220
Real estate loans | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,197,896	2,094,942
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	705,701	695,584
Commercial and industrial | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	651,204	624,643
Commercial and industrial | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	691,708	684,444
Commercial and industrial | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	639,463	615,817
Commercial and industrial | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	52,245	68,627
Commercial and industrial | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,581	2,737
Commercial and industrial | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,352	2,511
Commercial and industrial | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	229	226
Commercial and industrial | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	11,412	8,402
Commercial and industrial | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	9,389	6,314
Commercial and industrial | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,023	2,088
Commercial and industrial | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	1
Commercial and industrial | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	1
Commercial and industrial | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Commercial and industrial | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	705,701	695,584
Commercial and industrial | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	651,204	624,643
Commercial and industrial | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	54,497	70,941
Home equity loans and lines
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	204,791	207,351
Home equity loans and lines | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	180,075	181,506
Home equity loans and lines | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	197,373	203,037
Home equity loans and lines | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	173,197	177,916
Home equity loans and lines | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	24,176	25,121
Home equity loans and lines | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	7,418	4,314
Home equity loans and lines | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	6,878	3,590
Home equity loans and lines | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	540	724
Home equity loans and lines | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Home equity loans and lines | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	204,791	207,351
Home equity loans and lines | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	180,075	181,506
Home equity loans and lines | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	24,716	25,845
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	502,379	494,355
Residential mortgage | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	423,638	411,022
Residential mortgage | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	499,339	490,789
Residential mortgage | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	421,168	408,095
Residential mortgage | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	78,171	82,694
Residential mortgage | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	3,040	3,566
Residential mortgage | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,470	2,927
Residential mortgage | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	570	639
Residential mortgage | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Residential mortgage | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	502,379	494,355
Residential mortgage | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	423,638	411,022
Residential mortgage | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	78,741	83,333
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	47,821	46,814
Consumer | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	45,229	44,099
Consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	47,195	46,588
Consumer | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	44,647	43,936
Consumer | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,548	2,652
Consumer | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	626	226
Consumer | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	582	163
Consumer | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	44	63
Consumer | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Consumer | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	47,821	46,814
Consumer | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	45,229	44,099
Consumer | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	2,592	2,715
Leases
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	156,366	144,536
Leases | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	137,941	121,567
Leases | Pass
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	155,453	143,561
Leases | Pass | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	137,513	121,175
Leases | Pass | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	17,940	22,386
Leases | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Special Mention | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Special Mention | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	913	975
Leases | Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	428	392
Leases | Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	485	583
Leases | Doubtful
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Doubtful | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Doubtful | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	0	0
Leases | Pass, Special Mention and Substandard
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	156,366	144,536
Leases | Pass, Special Mention and Substandard | Originated
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	137,941	121,567
Leases | Pass, Special Mention and Substandard | Financial Asset Acquired With and Without Credit Deterioration
Loans and Leases Receivable Disclosure [Line Items]
Portfolio loans and leases	$ 18,425	$ 22,969