Loans and Loans Held for Sale - Restructured Loans by Type of Concession (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2018 USD ($) loan	Dec. 31, 2017 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		46	36
Pre-Modification Outstanding Recorded Investment	[1]	$ 12,672	$ 5,757
Post-Modification Outstanding Recorded Investment	[1]	11,384	6,142
Total Difference in Recorded Investment		$ (1,288)	$ 385
Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	29	26
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 1,221	$ 770
Post-Modification Outstanding Recorded Investment	[1],[2]	1,059	709
Total Difference in Recorded Investment	[2]	$ (162)	$ (61)
Interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 120	$ 0
Post-Modification Outstanding Recorded Investment	[1]	120	0
Total Difference in Recorded Investment		$ 0	$ 0
Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		3	3
Pre-Modification Outstanding Recorded Investment	[1]	$ 1,024	$ 905
Post-Modification Outstanding Recorded Investment	[1]	345	1,406
Total Difference in Recorded Investment		$ (679)	$ 501
Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	3
Pre-Modification Outstanding Recorded Investment	[1]	$ 47	$ 1,973
Post-Modification Outstanding Recorded Investment	[1]	46	1,918
Total Difference in Recorded Investment		$ (1)	$ (55)
Principal deferral and maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		6	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,355	$ 0
Post-Modification Outstanding Recorded Investment	[1]	5,341	0
Total Difference in Recorded Investment		$ (14)	$ 0
Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		5	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,905	$ 113
Post-Modification Outstanding Recorded Investment	[1]	4,473	113
Total Difference in Recorded Investment		$ (432)	$ 0
Principal forgiveness
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 1,996
Post-Modification Outstanding Recorded Investment	[1]	0	1,996
Total Difference in Recorded Investment		$ 0	$ 0
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 346	$ 400
Post-Modification Outstanding Recorded Investment	[1]	269	398
Total Difference in Recorded Investment		$ (77)	$ (2)
Commercial real estate | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 256	$ 400
Post-Modification Outstanding Recorded Investment	[1]	179	398
Total Difference in Recorded Investment		$ (77)	$ (2)
Commercial real estate | Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 90	$ 0
Post-Modification Outstanding Recorded Investment	[1]	90	0
Total Difference in Recorded Investment		$ 0	$ 0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		12	5
Pre-Modification Outstanding Recorded Investment	[1]	$ 10,938	$ 2,187
Post-Modification Outstanding Recorded Investment	[1]	9,890	2,695
Total Difference in Recorded Investment		$ (1,048)	$ 508
Commercial and industrial | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 768	$ 274
Post-Modification Outstanding Recorded Investment	[1]	166	777
Total Difference in Recorded Investment		$ (602)	$ 503
Commercial and industrial | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 1,800
Post-Modification Outstanding Recorded Investment	[1]	0	1,805
Total Difference in Recorded Investment		$ 0	$ 5
Commercial and industrial | Principal deferral and maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		6	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,355	$ 0
Post-Modification Outstanding Recorded Investment	[1]	5,341	0
Total Difference in Recorded Investment		$ (14)	$ 0
Commercial and industrial | Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		4	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,815	$ 113
Post-Modification Outstanding Recorded Investment	[1]	4,383	113
Total Difference in Recorded Investment		$ (432)	$ 0
Commercial construction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 1,996
Post-Modification Outstanding Recorded Investment	[1]	0	1,996
Total Difference in Recorded Investment		$ 0	$ 0
Commercial construction | Principal forgiveness
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 1,996
Post-Modification Outstanding Recorded Investment	[1]	0	1,996
Total Difference in Recorded Investment		$ 0	$ 0
Residential mortgage
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		5	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 387	$ 33
Post-Modification Outstanding Recorded Investment	[1]	374	31
Total Difference in Recorded Investment		$ (13)	$ (2)
Residential mortgage | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	5	1
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 387	$ 33
Post-Modification Outstanding Recorded Investment	[1],[2]	374	31
Total Difference in Recorded Investment	[2]	$ (13)	$ (2)
Home equity
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		25	23
Pre-Modification Outstanding Recorded Investment	[1]	$ 978	$ 1,093
Post-Modification Outstanding Recorded Investment	[1]	847	987
Total Difference in Recorded Investment		$ (131)	$ (106)
Home equity | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	22	21
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 811	$ 689
Post-Modification Outstanding Recorded Investment	[1],[2]	681	643
Total Difference in Recorded Investment	[2]	$ (130)	$ (46)
Home equity | Interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 120	$ 0
Post-Modification Outstanding Recorded Investment	[1]	120	0
Total Difference in Recorded Investment		$ 0	$ 0
Home equity | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 231
Post-Modification Outstanding Recorded Investment	[1]	0	231
Total Difference in Recorded Investment		$ 0	$ 0
Home equity | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 47	$ 173
Post-Modification Outstanding Recorded Investment	[1]	46	113
Total Difference in Recorded Investment		$ (1)	$ (60)
Installment and other consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	4
Pre-Modification Outstanding Recorded Investment	[1]	$ 23	$ 48
Post-Modification Outstanding Recorded Investment	[1]	4	35
Total Difference in Recorded Investment		$ (19)	$ (13)
Installment and other consumer | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	2	4
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 23	$ 48
Post-Modification Outstanding Recorded Investment	[1],[2]	4	35
Total Difference in Recorded Investment	[2]	$ (19)	$ (13)

[1] Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end

[2] Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.