Loans and Loans Held for Sale - Restructured Loans By Segment and Type of Concession (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2019 USD ($) loan	Mar. 31, 2018 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		10	21
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,522	$ 6,876
Post-Modification Outstanding Recorded Investment	[1]	5,499	6,770
Total Difference in Recorded Investment		$ (23)	$ (106)
Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 768
Post-Modification Outstanding Recorded Investment	[1]	0	708
Total Difference in Recorded Investment		$ 0	$ (60)
Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,201
Post-Modification Outstanding Recorded Investment	[1]	5,201
Total Difference in Recorded Investment		$ 0
Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	6
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 5,355
Post-Modification Outstanding Recorded Investment	[1]	0	5,333
Total Difference in Recorded Investment		$ 0	$ (22)
Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	8	13
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 240	$ 753
Post-Modification Outstanding Recorded Investment	[1],[2]	217	729
Total Difference in Recorded Investment	[2]	$ (23)	$ (24)
Interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 81
Post-Modification Outstanding Recorded Investment	[1]	81
Total Difference in Recorded Investment		$ 0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	8
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,201	$ 6,123
Post-Modification Outstanding Recorded Investment	[1]	5,201	6,041
Total Difference in Recorded Investment		$ 0	$ (82)
Commercial and industrial | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 768
Post-Modification Outstanding Recorded Investment	[1]	0	708
Total Difference in Recorded Investment		$ 0	$ (60)
Commercial and industrial | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 5,201	$ 0
Post-Modification Outstanding Recorded Investment	[1]	5,201	0
Total Difference in Recorded Investment		0	$ 0
Commercial and industrial | Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan			6
Pre-Modification Outstanding Recorded Investment	[1]		$ 5,355
Post-Modification Outstanding Recorded Investment	[1]		5,333
Total Difference in Recorded Investment		$ 0	$ (22)
Commercial construction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 158
Post-Modification Outstanding Recorded Investment	[1]	0	157
Total Difference in Recorded Investment		$ 0	$ (1)
Commercial construction | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	0	2
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 0	$ 158
Post-Modification Outstanding Recorded Investment	[1],[2]	0	157
Total Difference in Recorded Investment	[2]	$ 0	$ (1)
Residential mortgage
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 49	$ 0
Post-Modification Outstanding Recorded Investment	[1]	49	0
Total Difference in Recorded Investment		$ 0	$ 0
Residential mortgage | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	1	0
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 49	$ 0
Post-Modification Outstanding Recorded Investment	[1],[2]	49	0
Total Difference in Recorded Investment	[2]	$ 0	$ 0
Home equity
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		8	9
Pre-Modification Outstanding Recorded Investment	[1]	$ 272	$ 578
Post-Modification Outstanding Recorded Investment	[1]	249	555
Total Difference in Recorded Investment		$ (23)	$ (23)
Home equity | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	7	9
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 191	$ 578
Post-Modification Outstanding Recorded Investment	[1],[2]	168	555
Total Difference in Recorded Investment	[2]	$ (23)	$ (23)
Home equity | Interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 81	$ 0
Post-Modification Outstanding Recorded Investment	[1]	81	0
Total Difference in Recorded Investment		$ 0	$ 0
Installment and other consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 17
Post-Modification Outstanding Recorded Investment	[1]	0	17
Total Difference in Recorded Investment		$ 0	$ 0
Installment and other consumer | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	0	2
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 0	$ 17
Post-Modification Outstanding Recorded Investment	[1],[2]	0	17
Total Difference in Recorded Investment	[2]	$ 0	$ 0

[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.