Condensed Consolidated Balance Sheets [Parenthetical] (USD $)	Sep. 30, 2013	Dec. 31, 2012
Allowance for doubtful accounts receivable (in dollars)	$ 757,000	$ 653,000
Allowance for doubtful financing receivables 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	12,831,000	12,678,000
Common stock, shares outstanding	12,195,000	12,088,000
Treasury stock, shares	636,000	590,000