Stock-Based Compensation (Details) - Common stock options	12 Months Ended
	Dec. 31, 2017 $ / shares shares	Dec. 31, 2016 $ / shares shares
Options
Outstanding at beginning of year | shares	2,513,861	2,555,263
Granted | shares	155,000	739,000
Exercised | shares	(131,427)	(103,308)
Forfeited | shares	(52,932)	(469,856)
Expired | shares	(94,490)	(207,238)
Outstanding at end of year | shares	2,390,012	2,513,861
Stock options exercisable at year end | shares	1,583,585	1,329,392
Wtd. Avg. Exercise Price
Outstanding | $ / shares	$ 1.78	$ 1.80
Granted | $ / shares	2.93	1.80
Exercised | $ / shares	1.17	1.22
Forfeited | $ / shares	3.45	2.15
Expired | $ / shares	1.78	1.50
Outstanding | $ / shares	1.85	1.78
Stock options exercisable at September 30, 2017 | $ / shares	$ 1.72	$ 1.66