Fair Value of Financial Instruments Fair Value - Recurring and Nonrecurring (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	$ 340,411	$ 300,200	$ 315,459
Equity Securities	1,916	0	0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	340,411
Equity Securities	1,916
Total Securities Measured on a Recurring Basis	342,327
Securities Available-for-Sale		300,200	315,459
Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Equity Securities	0
Total Securities Measured on a Recurring Basis	0
Securities Available-for-Sale		0	64,730
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	340,411
Equity Securities	1,916
Total Securities Measured on a Recurring Basis	342,327
Securities Available-for-Sale		300,200	250,729
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Equity Securities	0
Total Securities Measured on a Recurring Basis	0
Securities Available-for-Sale		0	0
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Gain (Loss) on Collateral Dependent Impaired Loans		0
Other Real Estate and Repossessed Assets, Net	1,220	1,847	1,713
Gain (Loss) Other Real Estate and Repossessed Assets, Net	(559)	(569)	(655)
Fair Value, Measurements, Nonrecurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Other Real Estate and Repossessed Assets, Net	0	0	0
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Other Real Estate and Repossessed Assets, Net	0	0	0
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Other Real Estate and Repossessed Assets, Net	1,220	1,847	1,713
U.S. Agency Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	59,602	59,894	146,978
U.S. Agency Obligations | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	59,602
Securities Available-for-Sale		59,894	146,978
U.S. Agency Obligations | Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	64,730
U.S. Agency Obligations | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	59,602
Securities Available-for-Sale		59,894	82,248
U.S. Agency Obligations | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
State and Municipal Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	2,548	10,349	11,902
State and Municipal Obligations | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	2,548
Securities Available-for-Sale		10,349	11,902
State and Municipal Obligations | Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
State and Municipal Obligations | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	2,548
Securities Available-for-Sale		10,349	11,902
State and Municipal Obligations | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
Mortgage-Backed Securities - Residential | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	277,461
Securities Available-for-Sale		227,596	152,806
Mortgage-Backed Securities - Residential | Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
Mortgage-Backed Securities - Residential | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	277,461
Securities Available-for-Sale		227,596	152,806
Mortgage-Backed Securities - Residential | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
Corporate and Other Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	800	800	2,299
Corporate and Other Debt Securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	800
Securities Available-for-Sale		800	2,299
Corporate and Other Debt Securities | Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
Corporate and Other Debt Securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	800
Securities Available-for-Sale		800	2,299
Corporate and Other Debt Securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0
Securities Available-for-Sale		0	0
Mutual Funds and Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale	0	1,561	1,474
Mutual Funds and Equity Securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities			1,474
Securities Available-for-Sale		1,561
Mutual Funds and Equity Securities | Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities			0
Securities Available-for-Sale		0
Mutual Funds and Equity Securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities			1,474
Securities Available-for-Sale		1,561
Mutual Funds and Equity Securities | Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities			0
Securities Available-for-Sale		$ 0
Collateral Pledged | Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	857		1,502
Gain (Loss) on Collateral Dependent Impaired Loans	(58)		(138)
Collateral Pledged | Fair Value, Measurements, Nonrecurring | Quoted Prices In Active Markets for Indentical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0		0
Collateral Pledged | Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0		0
Collateral Pledged | Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	$ 857		$ 1,502