CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Preferred stock, convertible, shares authorized (in shares)	5,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	5,238,900	5,113,700
Common stock, shares outstanding (in shares)	5,140,500	4,981,200
Treasury stock, shares (in shares)	98,400	132,500
Series A-2 Preferred Stock
Preferred stock, convertible, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, convertible, stated value	$ 7,500	$ 7,500
Preferred stock, convertible, shares authorized (in shares)	7,500	7,500
Preferred stock, convertible, shares issued (in shares)	32	32
Preferred stock, convertible, shares outstanding (in shares)	32	32
Preferred stock, convertible, liquidation value	$ 331,000	$ 308,000
Series B Preferred Stock
Preferred stock, convertible, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, convertible, stated value	$ 1,000	$ 1,000
Preferred stock, convertible, shares authorized (in shares)	2,800	2,800
Preferred stock, convertible, shares issued (in shares)	0	75
Preferred stock, convertible, shares outstanding (in shares)	0	75
Preferred stock, convertible, liquidation value	$ 0	$ 75,000
Series C Preferred Stock
Preferred stock, convertible, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, convertible, stated value	$ 1,000	$ 1,000
Preferred stock, convertible, shares authorized (in shares)	1,750	1,750
Preferred stock, convertible, shares issued (in shares)	475	525
Preferred stock, convertible, shares outstanding (in shares)	475	525
Preferred stock, convertible, liquidation value	$ 475,000	$ 525,000