Condensed Financial Information - Parent Company Only (Schedule of Condensed Cash Flows Statement) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income	$ 2,081	$ 1,860	$ 2,521	$ 2,539	$ 1,710	$ 2,007	$ 2,027	$ 2,042	$ 1,805	$ 1,430	$ 1,610	$ 1,525	$ 9,001	$ 7,786	$ 6,370
Provision for (recovery of) loan losses													777	(625)	(188)
Adjustments to reconcile net income to net cash provided by operating activities
Fair value adjustment on derivative contract													0	0	(149)
Changes in assets and liabilities:
Decrease (increase) in other assets													2,404	1,465	1,095
(Decrease) in other liabilities													(11,477)	1,141	2,732
Net cash provided by operating activities													(1,523)	9,367	9,700
Cash Flows from Investing Activities
Net (increase) decrease in loans													40,545	51,401	21,995
Net cash (used in) provided by investing activities													(53,659)	(64,287)	(26,383)
Cash Flows from Financing Activities
Cash dividends paid													(2,776)	(2,652)	(2,354)
Issuance of common stock, employee benefit plan													163	166	81
Retirement of common stock													1,261	1,564	2,143
Net cash used in financing activities													37,687	55,487	28,743
(Decrease) increase in cash													(17,495)	567	12,060
Cash and Cash Equivalents
Beginning				35,848				35,281				23,221	35,848	35,281	23,221
Ending	18,353				35,848				35,281				18,353	35,848	35,281
Parent Company [Member]
Cash Flows from Operating Activities
Net income													9,001	7,786	6,370
Provision for (recovery of) loan losses													2	(2)	(2)
Adjustments to reconcile net income to net cash provided by operating activities
Fair value adjustment on derivative contract													0	0	(149)
Stock-based compensation expense													518	382	314
Undistributed earnings of subsidiary bank													(5,613)	(4,077)	(2,090)
Changes in assets and liabilities:
Decrease (increase) in other assets													(15)	62	39
(Decrease) in other liabilities													0	0	(568)
Net cash provided by operating activities													3,923	4,027	3,836
Cash Flows from Investing Activities
Net (increase) decrease in loans													73	(58)	(62)
Net cash (used in) provided by investing activities													(73)	58	62
Cash Flows from Financing Activities
Cash dividends paid													(2,776)	(2,652)	(2,354)
Issuance of common stock, employee benefit plan													163	166	81
Retirement of common stock													1,261	1,564	2,143
Net cash used in financing activities													(3,874)	(4,050)	(4,416)
(Decrease) increase in cash													(24)	35	(518)
Cash and Cash Equivalents
Beginning				$ 426				$ 391				$ 909	426	391	909
Ending	$ 402				$ 426				$ 391				$ 402	$ 426	$ 391