Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2016	4,896,875
Balance at Dec. 31, 2016	$ 5,918,000	$ 43,048,000	$ (972,000)	$ 47,994,000
Net income		8,189,000		8,189,000
Other comprehensive income (loss)			496,000	496,000
Cumulative effect of adopting of ASU 2016-09	84,000	(78,000)		6,000
Reclassification of stranded tax effects from change in tax rate		94,000	(94,000)
Exercise of stock options (in shares)	59,985
Exercise of stock options	$ 261,000			261,000
Cashless exercise of common stock warrant (in shares)	108,112
Cash dividends on common stock		(1,398,000)		(1,398,000)
Stock-based compensation expense	$ 152,000			152,000
Balance (in shares) at Dec. 31, 2017	5,064,972
Balance at Dec. 31, 2017	$ 6,415,000	49,855,000	(570,000)	55,700,000
Net income		13,992,000		13,992,000
Other comprehensive income (loss)			(1,447,000)	(1,447,000)
Exercise of stock options (in shares)	72,504
Exercise of stock options	$ 330,000			330,000
Cash dividends on common stock		(1,842,000)		(1,842,000)
Stock-based compensation expense	$ 199,000			199,000
Balance (in shares) at Dec. 31, 2018	5,137,476
Balance at Dec. 31, 2018	$ 6,944,000	62,005,000	(2,017,000)	66,932,000
Net income		15,512,000		15,512,000
Other comprehensive income (loss)			4,066,000	4,066,000
Exercise of stock options (in shares)	28,284
Exercise of stock options	$ 144,000			144,000
Cash dividends on common stock		(2,373,000)		(2,373,000)
Stock-based compensation expense	$ 224,000			224,000
Balance (in shares) at Dec. 31, 2019	5,165,760
Balance at Dec. 31, 2019	$ 7,312,000	$ 75,144,000	$ 2,049,000	$ 84,505,000