Stock And Stock Options (Schedule Of Stock Option Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock And Stock Options [Abstract]
Shares, Outstanding beginning of year	45,625	90,025	87,025
Shares, Granted	2,500	10,000	10,000
Shares, Exercised
Shares, Expired/cancelled	(10,625)	(54,400)	(7,000)
Shares, Outstanding end of year	37,500	45,625	90,025
Weighted Average Exercise Price, Outstanding beginning of year	$ 6.10	$ 5.70	$ 5.90
Weighted Average Exercise Price, Granted	1.20	2.40	4.40
Weighted Average Exercise Price, Exercised
Weighted Average Exercise Price, Expired/cancelled	9.88	4.80	6.30
Weighted Average Exercise Price, Outstanding end of year	$ 4.70	$ 6.10	$ 5.70
Excersiable, end of year, Shares	37,500	45,625	90,025
Excersiable, end of year, Weighted Average Exercise Price	$ 4.70	$ 6.10	$ 5.70