Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings
Balance, beginning of period at Dec. 31, 2015	$ 11,390,000	$ 49,000	$ 5,110,000	$ (102,000)	$ (9,000)	$ 6,342,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accrued dividends payable	(49,000)					(49,000)
Net unrealized holding income		0	0		(16,000)
Proceeds from options exercised	83,000	1,000	82,000
Net income	2,835,000					2,835,000
Balance, end of period at Dec. 31, 2016	14,243,000	50,000	5,192,000	(102,000)	(25,000)	9,128,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accrued dividends payable	(256,000)					(256,000)
Net unrealized holding income	6,000				6,000
Proceeds from options exercised	117,000	1,000	116,000
Vesting of restricted stock	411,000	1,000	410,000
Net income	2,684,000					2,684,000
Balance, end of period at Dec. 31, 2017	$ 17,205,000	$ 52,000	$ 5,718,000	$ (102,000)	$ (19,000)	$ 11,556,000