Stock-based Compensation - Options Outstanding and Exercisable (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended				9 Months Ended
	Mar. 31, 2018	Feb. 28, 2018	Apr. 30, 2017	Mar. 31, 2016	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Additional disclosures
Stock based compensation expense related to shares issued for services					$ 10	$ 10	$ 45
2008 LTIP | Common Stock | Directors
Additional disclosures
Shares issued for services	18,906		30,002
Stock based compensation expense related to shares issued for services	$ 45		$ 53
2008 LTIP | Stock Options
Outstanding
Number Outstanding					537,500			540,625	537,500	540,625	537,500	540,625
Weighted Average Remaining Contractual Life									6 years 3 months 11 days
Weighted Average Exercise Price					$ 2.19			$ 2.18	$ 2.19	$ 2.18	$ 2.19	$ 2.18
Exercisable
Number Outstanding (Exercisable)					267,500			180,625	267,500	180,625
Weighted Average Exercise Price (Exercisable)					$ 2.71			$ 3.29	$ 2.71	$ 3.29
Additional disclosures
Stock based compensation expense (reversal of expense)					$ 10			$ 10	$ 29	$ 29
Period for recognizing unrecognized compensation cost									2 years 4 months 24 days
2008 LTIP | Stock Options | January 21, 2009
Outstanding
Number Outstanding					7,500				7,500
Weighted Average Remaining Contractual Life									3 months 18 days
Weighted Average Exercise Price					$ 4.00				$ 4.00
Exercisable
Number Outstanding (Exercisable)					7,500				7,500
Weighted Average Exercise Price (Exercisable)					$ 4.00				$ 4.00
2008 LTIP | Stock Options | March 18, 2009
Outstanding
Number Outstanding					75,000				75,000
Weighted Average Remaining Contractual Life									5 months 16 days
Weighted Average Exercise Price					$ 4.98				$ 4.98
Exercisable
Number Outstanding (Exercisable)					75,000				75,000
Weighted Average Exercise Price (Exercisable)					$ 4.98				$ 4.98
2008 LTIP | Stock Options | January 21, 2010
Outstanding
Number Outstanding					5,000				5,000
Weighted Average Remaining Contractual Life									1 year 3 months 18 days
Weighted Average Exercise Price					$ 6.00				$ 6.00
Exercisable
Number Outstanding (Exercisable)					5,000				5,000
Weighted Average Exercise Price (Exercisable)					$ 6.00				$ 6.00
2008 LTIP | Stock Options | February 24, 2016
Outstanding
Number Outstanding					450,000				450,000
Weighted Average Remaining Contractual Life									7 years 4 months 24 days
Weighted Average Exercise Price					$ 1.62				$ 1.62
Exercisable
Number Outstanding (Exercisable)					180,000				180,000
Weighted Average Exercise Price (Exercisable)					$ 1.62				$ 1.62
2008 LTIP | Restricted stock | Chief Executive Officer
Additional disclosures
Restricted stock award (in shares)				120,483
Stock based compensation expense (reversal of expense)					$ 3			26	$ 33	79
Unrecognized compensation cost, restricted stock					6				$ 6
Period for recognizing unrecognized compensation cost									6 months
2008 LTIP | Restricted stock | Two-year period | Chief Executive Officer
Additional disclosures
Restricted stock award (in shares)				100,000
Vesting period of stock award				2 years
2008 LTIP | Restricted stock | Three-year period | Chief Executive Officer
Additional disclosures
Restricted stock award (in shares)				20,483
Vesting period of stock award				3 years
2008 LTIP | Cash-settled restricted stock units | Chief Executive Officer
Additional disclosures
Restricted stock award (in shares)		97,195	129,270
Vesting period of stock award			2 years
Stock based compensation expense (reversal of expense)					$ (37)			$ 40	$ 27	$ 62