Liquidity (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Liquidity [Abstract]
Cash and cash equivalents	$ 5,711,000	$ 9,370,000	$ 6,581,000
Liquidity, management evaluation	Management believes that its existing resources will be sufficient to fund its planned operations through mid-April 2017.