Debt - Long-term and Short-term, Combined (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Apr. 01, 2016
Debt, long-term and short-term, combined amount
Total debt	$ 0	$ 3,261,000
Less current portion	0	(3,261,000)
Long-term portion	0	$ 0
Line of credit with FGI | Line of Credit
Debt, long-term and short-term, combined amount
Interest rate (as a percent)		6.50%
Total debt	0	$ 1,458,000
Convertible Debt | 2.0 million 8% shareholder note due 2017
Debt, long-term and short-term, combined amount
Face amount of debt	$ 2,000,000		$ 2,000,000.0
Interest rate (as a percent)	8.00%		8.00%
Total debt	$ 0	$ 1,803,000
Unamortized debt discount	$ 200,000