Condensed Consolidated Balance Sheets [Parenthetical] - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Allowance for doubtful accounts receivable (in dollars)	$ 1,580,000	$ 1,434,000
Allowance for notes and sales type lease receivable doubtfull accounts (in dollars)	$ 0	$ 0
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	14,214,000	13,476,000
Common stock, shares outstanding	13,471,000	12,812,000
Treasury stock, shares	743,000	664,000