CONSOLIDATED CONDENSED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Treasury Shares [Member]	Accumulated Other Comprehensive Income [Member]	Calculated under Revenue Guidance in Effect before Topic 606 [Member]	Calculated under Revenue Guidance in Effect before Topic 606 [Member] Common Stock [Member]	Calculated under Revenue Guidance in Effect before Topic 606 [Member] Retained Earnings [Member]	Calculated under Revenue Guidance in Effect before Topic 606 [Member] Treasury Shares [Member]	Calculated under Revenue Guidance in Effect before Topic 606 [Member] Accumulated Other Comprehensive Income [Member]	Difference between Revenue Guidance in Effect before and after Topic 606 [Member]	Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Retained Earnings [Member]	Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Accumulated Other Comprehensive Income [Member]
Balance Beginning (in shares) at Dec. 31, 2017		10,023,059					10,023,059
Balance beginning at Dec. 31, 2017	$ 150,271	$ 76,977	$ 87,826	$ (11,665)	$ (2,867)		$ 76,977	$ 87,301	$ (11,665)	$ (2,342)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,713		2,713
Other comprehensive income, net of taxes	(2,976)				(2,976)
Dividend Reinvestment and Stock Purchase Plan (in shares)		4,828
Dividend Reinvestment and Stock Purchase Plan	93	$ 93
Exercise of stock options (in shares)		2,631
Exercise of stock options	33	$ 33
Compensation expense relating to restricted stock (in shares)		10,634
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	56	$ 56
Common stock dividends, $0.16 per share	(1,606)		(1,606)
Cumulative effect of changes in accounting principles | Accounting Standards Update 2014-09 [Member]												$ 525	$ (525)
Balance Ending (in shares) at Mar. 31, 2018		10,041,152
Balance ending at Mar. 31, 2018	148,584	$ 77,159	88,933	(11,665)	(5,843)
Balance Beginning (in shares) at Dec. 31, 2017		10,023,059					10,023,059
Balance beginning at Dec. 31, 2017	150,271	$ 76,977	87,826	$ (11,665)	(2,867)		$ 76,977	87,301	(11,665)	(2,342)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of changes in accounting principles | Accounting Standards Update 2014-09 [Member]											$ (525)
Balance Ending (in shares) at Dec. 31, 2018							13,295,276
Balance ending at Dec. 31, 2018	218,985					$ 218,985	$ 141,170	94,547	(12,013)	(4,719)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,627		4,627
Other comprehensive income, net of taxes	2,489				2,489
Dividend Reinvestment and Stock Purchase Plan (in shares)		6,368
Dividend Reinvestment and Stock Purchase Plan	109	$ 109
Compensation expense relating to restricted stock (in shares)		12,504
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition	70	$ 70
Common stock dividends, $0.16 per share	(2,262)		$ (2,262)
Balance Ending (in shares) at Mar. 31, 2019							13,314,148
Balance ending at Mar. 31, 2019	$ 224,018				$ (2,230)		$ 141,349	$ 96,912	$ (12,013)	$ (2,230)