Loans - Loan Modifications by Concession Type (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($) loan	Sep. 30, 2018 USD ($) loan	Sep. 30, 2017 USD ($) loan
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 3,387	$ 2,926	$ 9,333	$ 6,608
Total number of loans (in loan) | loan	33	38	114	73
Pre-modification recorded investment	$ 3,404	$ 3,071	$ 9,446	$ 6,864
Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	2,681	780	5,383	1,993
Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	324		431
Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	381	479	2,744	2,247
Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	1	1,667	775	2,368
Commercial loan portfolio
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 2,774	$ 2,558	$ 7,800	$ 5,548
Total number of loans (in loan) | loan	16	19	56	37
Pre-modification recorded investment	$ 2,784	$ 2,627	$ 7,845	$ 5,646
Commercial loan portfolio | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	2,542	541	4,623	1,323
Commercial loan portfolio | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	66		66
Commercial loan portfolio | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	165	350	2,336	1,857
Commercial loan portfolio | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	1	1,667	775	2,368
Commercial loan portfolio | Commercial
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 2,270	$ 2,119	$ 5,457	$ 4,400
Total number of loans (in loan) | loan	13	14	44	26
Pre-modification recorded investment	$ 2,277	$ 2,173	$ 5,481	$ 4,476
Commercial loan portfolio | Commercial | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	2,104	506	3,747	841
Commercial loan portfolio | Commercial | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0		0
Commercial loan portfolio | Commercial | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	165	281	1,448	1,648
Commercial loan portfolio | Commercial | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	1	1,332	262	1,911
Commercial loan portfolio | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 504	$ 404	$ 2,343	$ 1,113
Total number of loans (in loan) | loan	3	4	12	10
Pre-modification recorded investment	$ 507	$ 418	$ 2,364	$ 1,134
Commercial loan portfolio | Total commercial real estate | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	438	0	876	447
Commercial loan portfolio | Total commercial real estate | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	66		66
Commercial loan portfolio | Total commercial real estate | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	69	888	209
Commercial loan portfolio | Total commercial real estate | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	335	513	457
Commercial loan portfolio | Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment		$ 35		$ 35
Total number of loans (in loan) | loan		1		1
Pre-modification recorded investment		$ 36		$ 36
Commercial loan portfolio | Real estate construction and land development | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment		35		35
Commercial loan portfolio | Real estate construction and land development | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment		0		0
Commercial loan portfolio | Real estate construction and land development | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment		0		0
Consumer loan portfolio
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 613	$ 368	$ 1,533	$ 1,060
Total number of loans (in loan) | loan	17	19	58	36
Pre-modification recorded investment	$ 620	$ 444	$ 1,601	$ 1,218
Consumer loan portfolio | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	139	239	760	670
Consumer loan portfolio | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	258		365
Consumer loan portfolio | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	216	129	408	390
Consumer loan portfolio | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	0	0	0
Consumer loan portfolio | Residential mortgage
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 219	$ 198	$ 567	$ 594
Total number of loans (in loan) | loan	2	3	9	9
Pre-modification recorded investment	$ 220	$ 262	$ 577	$ 676
Consumer loan portfolio | Residential mortgage | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	76	269	211
Consumer loan portfolio | Residential mortgage | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	111		151
Consumer loan portfolio | Residential mortgage | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	108	122	147	383
Consumer loan portfolio | Residential mortgage | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	0	0	0
Consumer loan portfolio | Consumer installment
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 166	$ 54	$ 357	$ 86
Total number of loans (in loan) | loan	11	11	36	17
Pre-modification recorded investment	$ 172	$ 58	$ 372	$ 93
Consumer loan portfolio | Consumer installment | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	48	47	134	79
Consumer loan portfolio | Consumer installment | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	74		141
Consumer loan portfolio | Consumer installment | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	44	7	82	7
Consumer loan portfolio | Consumer installment | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	0	0	0
Consumer loan portfolio | Home equity
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 228	$ 116	$ 609	$ 380
Total number of loans (in loan) | loan	4	5	13	10
Pre-modification recorded investment	$ 228	$ 124	$ 652	$ 449
Consumer loan portfolio | Home equity | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	91	116	357	380
Consumer loan portfolio | Home equity | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	73		73
Consumer loan portfolio | Home equity | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	64	0	179	0
Consumer loan portfolio | Home equity | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	0	0	0
Owner-occupied | Commercial loan portfolio | Commercial
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 438	$ 377	$ 2,209	$ 1,086
Total number of loans (in loan) | loan	2	3	10	9
Pre-modification recorded investment	$ 438	$ 390	$ 2,221	$ 1,106
Owner-occupied | Commercial loan portfolio | Commercial | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	438	0	808	447
Owner-occupied | Commercial loan portfolio | Commercial | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0		0
Owner-occupied | Commercial loan portfolio | Commercial | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	42	888	182
Owner-occupied | Commercial loan portfolio | Commercial | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	335	513	457
Non-owner occupied | Commercial loan portfolio | Commercial
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 66	$ 27	$ 134	$ 27
Total number of loans (in loan) | loan	1	1	2	1
Pre-modification recorded investment	$ 69	$ 28	$ 143	$ 28
Non-owner occupied | Commercial loan portfolio | Commercial | Principal deferral
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	0	68	0
Non-owner occupied | Commercial loan portfolio | Commercial | Principal reduction
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	66		66
Non-owner occupied | Commercial loan portfolio | Commercial | Interest rate
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	0	27	0	27
Non-owner occupied | Commercial loan portfolio | Commercial | Forbearance agreement
Financing Receivable, Modifications [Line Items]
Post-modification recorded investment	$ 0	$ 0	$ 0	$ 0