Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 113	$ 185
Preferred stock, par value (USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	597,139	546,466
Preferred stock, shares outstanding (in shares)	597,139	546,466
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	7,500,000	7,500,000
Common stock, shares issued (in shares)	2,466,219	2,366,219
Common stock, shares outstanding (in shares)	2,466,219	2,366,219