Consolidated Balance Sheets Parenthetical (USD $)	Mar. 31, 2012	Dec. 31, 2011
Current assets
Accounts receivable, allowance for doubtful accounts	$ 27,419	$ 24,290
Equity
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	1,000	1,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	16,017,142	16,017,142
Common stock, shares outstanding (in shares)	15,354,711	15,364,711
Treasury stock, at cost (in shares)	662,431	652,431