Loans and Loans Held for Sale - Restructured Loans During Periods Presented (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2017 USD ($) contract		Mar. 31, 2016 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		7		16
Pre-Modification Outstanding Recorded Investment	[1]	$ 442		$ 2,646
Post-Modification Outstanding Recorded Investment	[1]	438		2,614
Total Difference in Recorded Investment		$ (4)		$ (32)
Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		0
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 0
Post-Modification Outstanding Recorded Investment	[1]	0		0
Total Difference in Recorded Investment		$ 0		$ 0
Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | contract	[2]	6		9
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 269		$ 1,175
Post-Modification Outstanding Recorded Investment	[1],[2]	266		1,164
Total Difference in Recorded Investment	[2]	$ (3)		$ (11)
Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		6
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 1,341
Post-Modification Outstanding Recorded Investment	[1]	0		1,320
Total Difference in Recorded Investment		$ 0		$ (21)
Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		1		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 173		$ 130
Post-Modification Outstanding Recorded Investment	[1]	172		130
Total Difference in Recorded Investment		$ (1)		$ 0
Commercial Real Estate | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | contract	[2]	0		1
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 0		$ 709
Post-Modification Outstanding Recorded Investment	[1],[2]	0		702
Total Difference in Recorded Investment	[2]	$ 0		$ (7)
Commercial And Industrial | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 625
Post-Modification Outstanding Recorded Investment	[1]	0		605
Total Difference in Recorded Investment		$ 0		$ (20)
Commercial Construction | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 33
Post-Modification Outstanding Recorded Investment	[1]	0		33
Total Difference in Recorded Investment		$ 0		$ 0
Residential Mortgage | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0	[1]	3	[2]
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 0		$ 221
Post-Modification Outstanding Recorded Investment	[1],[2]	0		219
Total Difference in Recorded Investment	[2]	$ 0		$ (2)
Residential Mortgage | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 483
Post-Modification Outstanding Recorded Investment	[1]	0		483
Total Difference in Recorded Investment		$ 0		$ 0
Home Equity Loan | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | contract	[2]	6		5
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 269		$ 245
Post-Modification Outstanding Recorded Investment	[1],[2]	266		243
Total Difference in Recorded Investment	[2]	$ (3)		$ (2)
Home Equity Loan | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		0		2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0		$ 200
Post-Modification Outstanding Recorded Investment	[1]	0		199
Total Difference in Recorded Investment		$ 0		$ (1)
Home Equity Loan | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | contract		1		1
Pre-Modification Outstanding Recorded Investment	[1]	$ 173		$ 130
Post-Modification Outstanding Recorded Investment	[1]	172		130
Total Difference in Recorded Investment		$ (1)		$ 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.