FINANCING AGREEMENTS (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	May 02, 2012
Financing arrangements
Outstanding balance	$ 7,234,983	$ 7,923,487
Total long-term debt	1,333,463	1,091,110
Current maturities of long-term debt	(632,176)	(453,105)
Long-term debt - net of current maturities	4,246,914	2,865,899
Future maturity requirements for long-term debt
2014	632,176
2015	640,093
2016	537,176
2017	537,176
2018	310,067
Future	2,222,402
Total long-term debt	1,333,463	1,091,110
Line of credit
Financing arrangements
Maximum borrowing capacity			13,500,000
Variable rate basis	three-month LIBOR
Interest rate margin on variable rate basis (as a percent)	2.75%
Interest rate (as a percent)	3.00%
Weighted-average interest rate (as a percent)	3.15%
Outstanding balance	7,234,983	7,923,487
Unused availability supported by entity's borrowing base	5,800,000
Real estate term note
Financing arrangements
Variable rate basis	three-month LIBOR
Interest rate margin on variable rate basis (as a percent)	3.25%
Interest rate (as a percent)	3.50%
Weighted-average interest rate (as a percent)	3.58%
Real estate term note maturing on March 31, 2027
Financing arrangements
Debt instrument, face amount			1,800,000
Real estate term note expiring on May 31, 2012
Financing arrangements
Debt instrument, face amount			900,000
Term loan
Financing arrangements
Long-term debt - net of current maturities	1,400,000
Term loan | Maximum
Financing arrangements
Debt instrument, face amount			2,000,000
Equipment term loan tied to equipment purchased in Mankato acquisition
Financing arrangements
Debt instrument, additional borrowing amount		1,700,000
Industrial revenue bond payable to the City of Blue Earth, Minnesota
Financing arrangements
Interest rate (as a percent)	0.30%
Amount of annual principal payments	80,000
Total long-term debt	440,000	520,000
Future maturity requirements for long-term debt
Total long-term debt	440,000	520,000
Equipment notes maturing in May 2015
Financing arrangements
Variable rate basis	three-month LIBOR
Interest rate margin on variable rate basis (as a percent)	3.25%
Interest rate (as a percent)	3.50%
Amount of monthly principal payments	27,000
Total long-term debt	1,333,463	1,091,110
Future maturity requirements for long-term debt
Total long-term debt	1,333,463	1,091,110
Real estate term notes
Financing arrangements
Variable rate basis	three-month LIBOR
Interest rate margin on variable rate basis (as a percent)	2.75%
Interest rate (as a percent)	3.00%
Amount of monthly principal payments	19,000
Total long-term debt	3,105,627	1,707,894
Future maturity requirements for long-term debt
Total long-term debt	$ 3,105,627	$ 1,707,894