Shareholders' Equity - Price Range (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Options Outstanding
Number Outstanding (in shares)	419,162
Weighted Average Remaining Contractual Life	5 years 8 months 19 days
Weighted Average Exercise Price Per Share	$ 3.18
Options Exercisable
Number Exercisable (in shares)	381,836	653,840
Weighted Average Exercise Price Per Share	$ 3.19
Stock option disclosures
Aggregate intrinsic value of options outstanding (in dollars)	$ 74,000
Weighted average remaining life of options exercisable	5 years 6 months 18 days
Aggregate intrinsic value of options exercisable (in dollars)	$ 74,000
Weighted average grant-date fair value of options granted (in dollars per share)	$ 0.56	$ 0.94
Exercise Price Range One [Member]
Range of Exercise Prices
Lower (in dollars per share)	1.61
Upper (in dollars per share)	$ 2.79
Options Outstanding
Number Outstanding (in shares)	107,830
Weighted Average Remaining Contractual Life	5 years 5 months 1 day
Weighted Average Exercise Price Per Share	$ 1.79
Options Exercisable
Number Exercisable (in shares)	107,830
Weighted Average Exercise Price Per Share	$ 1.79
Exercise Price Range Two [Member]
Range of Exercise Prices
Lower (in dollars per share)	2.80
Upper (in dollars per share)	$ 4.22
Options Outstanding
Number Outstanding (in shares)	262,832
Weighted Average Remaining Contractual Life	6 years 3 months 4 days
Weighted Average Exercise Price Per Share	$ 3.32
Options Exercisable
Number Exercisable (in shares)	225,506
Weighted Average Exercise Price Per Share	$ 3.37
Exercise Price [Member]
Range of Exercise Prices
Exercise price (in dollars per share)	$ 5.49
Options Outstanding
Number Outstanding (in shares)	48,500
Weighted Average Remaining Contractual Life	3 years 4 months 24 days
Weighted Average Exercise Price Per Share	$ 5.49
Options Exercisable
Number Exercisable (in shares)	48,500
Weighted Average Exercise Price Per Share	$ 5.49
Stock Option Plan2013 [Member] | Board Of Directors [Member]
Stock option disclosures
Total number of stock awards granted to the Board of Directors (in shares)	54,036	37,233
Shares issue price (in dollars per share)	$ 2.19	$ 2.82
Total value of shares issued	$ 119,000	$ 105,000
Accrued stock-based compensation	$ 0	$ 10,000
Restricted Stock and Restricted Stock Units [Member]
Number of Shares
Outstanding at the beginning of the period (in shares)	88,666	25,000
Granted (in shares)	189,875	99,000
Vested ( in shares)	(23,167)	(8,334)
Forfeited or surrendered (in shares)	(50,499)	(27,000)
Outstanding at the end of the period (in shares)	204,875	88,666
Weighted average grant date fair value
Beginning balance fair value (per share)	$ 2.72	$ 3.03
Granted (per share)	2.11	2.71
Vested (per share)	2.68	3.03
Forfeited or surrendered (per share)	2.72	2.89
Ending balance fair value (per share)	$ 2.16	$ 2.72
Restricted Stock and Restricted Stock Units [Member] | Stock Option Plan2013 [Member]
Number of Shares
Granted (in shares)	189,875	99,000