Loans - Aging of Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 35,928	$ 17,153
Loans Not Past Due	2,819,278	2,792,044
Total ending loans balance	2,855,206	2,809,197
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	18,145	5,278
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	7,324	2,366
Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	10,459	9,509
Commercial, Industrial and Agricultural
Financing Receivable, Past Due [Line Items]
Total Past Due	13,664	5,605
Loans Not Past Due	1,077,251	1,041,060
Total ending loans balance	1,090,915	1,046,665
Commercial, Industrial and Agricultural | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,604	1,273
Commercial, Industrial and Agricultural | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	6,251	548
Commercial, Industrial and Agricultural | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	4,809	3,784
Commercial mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	14,551	2,939
Loans Not Past Due	831,664	811,063
Total ending loans balance	846,215	814,002
Commercial mortgages | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	11,773	162
Commercial mortgages | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	179	183
Commercial mortgages | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,599	2,594
Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	6,509	7,367
Loans Not Past Due	808,148	806,663
Total ending loans balance	814,657	814,030
Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,285	3,383
Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	623	1,270
Residential real estate | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,601	2,714
Consumer
Financing Receivable, Past Due [Line Items]
Total Past Due	1,121	1,138
Loans Not Past Due	93,304	123,647
Total ending loans balance	94,425	124,785
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	450	412
Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	238	311
Consumer | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	433	415
Credit cards
Financing Receivable, Past Due [Line Items]
Total Past Due	83	104
Loans Not Past Due	8,600	7,465
Total ending loans balance	8,683	7,569
Credit cards | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	33	48
Credit cards | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	33	54
Credit cards | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	17	2
Overdrafts
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Loans Not Past Due	311	2,146
Total ending loans balance	311	2,146
Overdrafts | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Overdrafts | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Overdrafts | Greater Than 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 0	$ 0