Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended		75 Months Ended
	Jan. 25, 2018	May 24, 2017	Aug. 24, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Feb. 28, 2018	Mar. 24, 2017	Aug. 31, 2011
Class of Stock [Line Items]
Exercise of common stock options, shares				99,937
Proceeds from exercise of stock options				$ 98	$ 140
Repurchase program, amount authorzied									$ 2,500
Repurchase program, amount remaining					2,000
Shares repurchased						0
Number of warrants exercised				30,000
Proceeds from exercise of warrants				$ 46
Underwriting agreement to issue and sell common stock	9,807,105	3,300,000
Number of shares of common stock called by warrants	3,922,842	1,650,000						100,000
Warrants exercise price per share	$ 1.55	$ 2.45						$ 2.25
Warrant term		5 years
Common stock, price per share	$ 1.35	$ 2.00
Number of shares of common stock called by each warrant	0.4
Offering close date				Jan. 29, 2018
Proceeds from underwriting agreement, net	$ 11,900	$ 5,900		$ 12,172	$ 5,919
December 2015 [Member]
Class of Stock [Line Items]
Number of warrants exercised			2,216,500
Warrants exercise price per share				$ 2.05		$ 2.05
Warrants outstanding				383,500		383,500
Warrant expiration				Jun. 30, 2021
New Warrants [Member]
Class of Stock [Line Items]
Proceeds from exercise of warrants			$ 4,300
Number of shares of common stock called by warrants			2,947,949
Warrants exercise price per share			$ 2.60	$ 2.60		$ 2.60
Warrant exercisable beginning period			6 months
Warrant term			5 years 6 months
Percentage of shares issued to number of warrants exercised			133.00%
Warrants outstanding				2,947,949		2,947,949
Warrant expiration				Feb. 28, 2023
Private Placement [Member]
Class of Stock [Line Items]
Underwriting agreement to issue and sell common stock	203,708
Number of shares of common stock called by warrants	81,487
Common stock, price per share	$ 1.35
Offering close date				Feb. 15, 2018
Proceeds from underwriting agreement, net	$ 300
Public Offering and Private Placement [Member]
Class of Stock [Line Items]
Number of shares of common stock called by warrants							4,007,689
Warrants exercise price per share							$ 1.55
Warrants outstanding				3,977,689		3,977,689
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares designated				10,000	10,000	10,000
Preferred stock, shares issued				5,659	5,659	5,659
Preferred stock, shares outstanding				5,659	5,659	5,659
Preferred stock, conversion price per share				$ 0.75		$ 0.75
Preferred stock, redemption price per share				$ 1,000		$ 1,000