Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of selling costs		10.00%
Consumer mortgage loans in process of foreclosure		$ 0
Investment Securities Available-for-Sale		495,814	$ 481,596	$ 452,842
Gains (losses) for assets categorized as Level 3 assets		0
Level 1 to Level 2 transfers		0
Level 2 to Level 1 transfers		0
Transfer into Level 3		0	0
Transfer out of Level 3		0	0
Government Agency & Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		3,095	3,128	3,217
US Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		143,409	144,164	104,419
US Govt SBA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		27,537	29,380	34,734
Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale	[1]	318,763	301,914	309,462
Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		3,010	3,010	1,010
Significant Unobservable Inputs (Level 3) [Member] | SBA Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		2,500
Amount of increase in investment			2,000
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		495,814	481,596	452,842
Recurring [Member] | Government Agency & Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		3,095	3,128	3,217
Recurring [Member] | US Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		143,409	144,164	104,419
Recurring [Member] | US Govt SBA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		27,537	29,380	34,734
Recurring [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		318,763	301,914	309,462
Recurring [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		3,010	3,010	1,010
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		143,609	144,364	104,619
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Government Agency & Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		143,409	144,164	104,419
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Govt SBA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		200	200	200
Recurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		349,705	334,732	347,723
Recurring [Member] | Other Observable Inputs (Level 2) [Member] | Government Agency & Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		3,095	3,128	3,217
Recurring [Member] | Other Observable Inputs (Level 2) [Member] | US Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Other Observable Inputs (Level 2) [Member] | US Govt SBA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		27,537	29,380	34,734
Recurring [Member] | Other Observable Inputs (Level 2) [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		318,763	301,914	309,462
Recurring [Member] | Other Observable Inputs (Level 2) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		310	310	310
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		2,500	2,500	500
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Government Agency & Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | US Treasury Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | US Govt SBA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		0	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Securities Available-for-Sale		$ 2,500	$ 2,500	$ 500

[1] All Mortgage Backed Securities consist of securities collateralized by residential real estate and were issued by an agency or government sponsored entity of the U.S. government.