Convertible Debt at Fair Value (Narrative) (Details) - USD ($)			3 Months Ended								12 Months Ended
	Mar. 01, 2017	Mar. 16, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Gain (loss) on derivatives and convertible debt			$ (402,000)	$ 116,000	$ 156,000	$ 447,000	$ 20,000	$ 14,000	$ 227,000	$ 175,000	$ 317,000	$ 436,000	$ 6,377,000
6.25% Convertible Debt [Member]
Debt Instrument [Line Items]
Interest rate		6.25%	6.25%								6.25%
Principal amount		$ 1,012,000
Maximum ownership percentage of voting stock upon debt conversion		49.00%
Gain (loss) on derivatives and convertible debt											$ 69,000	$ 246,000	$ (303,000)
6.25% Convertible Debt [Member] | Series D Preferred Stock [Member]
Debt Instrument [Line Items]
Number of shares of common stock debt can convert into		97,269
6.25% Convertible Debt [Member] | Series E Preferred Stock [Member]
Debt Instrument [Line Items]
Number of shares of common stock debt can convert into	97,269