Income Taxes (Components of Deferred Tax Assets) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets, Net [Abstract]
Net operating loss carry-forwards	$ 44,157,000	$ 44,049,000
Research and development and other tax credits, net	2,523,000	3,109,000
Stock-based compensation	272,000	188,000
Other	196,000	165,000
Deferred tax assets, gross	47,148,000	47,511,000
Valuation allowance for deferred tax assets	(47,148,000)	(47,511,000)
Deferred Tax Liabilities, Net [Abstract]
In-process research and development	(819,000)	(1,147,000)
Total deferred tax liabilities	$ (819,000)	$ (1,147,000)