Schedule of Changes in Common Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options outstanding, beginning of year	2,165,000	2,130,000
Options, Granted (in shares)	50,000	100,000
Options, Exercised (in shares)	0	0
Options expired	(40,000)	(47,500)
Options forfeited	0	(17,500)
Options outstanding, end of year	2,175,000	2,165,000
Options, Exercisable (in shares)	1,743,750	1,330,000
Weighted Average Exercise Price, Outstanding at beginning of year (in dollars per share)	$ 1.71	$ 1.75
Weighted Average Exercise Price, Granted (in dollars per share)	0.42	0.70
Weighted Average Exercise Price, Expired	0.90	1.18
Weighted Average Exercise Price, Forfeited		2.00
Weighted Average Exercise Price, Outstanding at end of year (in dollars per share)	1.70	1.71
Weighted Average Exercise Price, Options exercisable at end of year (in dollars per share)	1.78	1.75
Weighted-average fair value of options granted during the year	$ 0.29	$ 0.36