FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $)	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Cash and cash equivalents [Abstract]
Cash and cash equivalents	$ 33,305,908	$ 34,581,394	$ 32,400,814	$ 30,662,104
Cash	11,237,309
Money market funds	22,068,599
Number of financial institutions	20
Short-term investments [Abstract]
Certificates of deposit, short-term	1,022,266	764,061
Schedule of Short Term Investments, by Maturity [Line Items]
Number of short-term certificates of deposit	4
Period from inception to maturity	12 months
Long-term investments [Abstract]
Certificates of deposit	0	494,537
Number of long-term certificates of deposit		2
Period from inception to maturity, minimum		14 months
Period from inception to maturity, maximum		15 months
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	33,305,908	34,581,394
Short-term investments	1,022,266	764,061
Long-term investments		494,537
Cash surrender value - life insurance policies	1,389,781	1,089,989
Interest rate swap agreement	(302,972)	(366,286)
Total financial assets (liabilities)	35,414,983	36,563,695
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	33,305,908	34,581,394
Short-term investments	1,022,266	764,061
Long-term investments		494,537
Cash surrender value - life insurance policies	0	0
Interest rate swap agreement	0	0
Total financial assets (liabilities)	34,328,174	35,839,992
Recurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Short-term investments	0	0
Long-term investments		0
Cash surrender value - life insurance policies	1,389,781	1,089,989
Interest rate swap agreement	(302,972)	(366,286)
Total financial assets (liabilities)	1,086,809	723,703
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Short-term investments	0	0
Long-term investments		0
Cash surrender value - life insurance policies	0	0
Interest rate swap agreement	0	0
Total financial assets (liabilities)	0	0
Fair value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	2,853,342	3,747,061
Carrying amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt	$ 2,639,507	$ 3,345,187
First Maturity Period [Member]
Schedule of Short Term Investments, by Maturity [Line Items]
Number of short-term certificates of deposit		2
Period from inception to maturity		9 months
Second Maturity Period [Member]
Schedule of Short Term Investments, by Maturity [Line Items]
Number of short-term certificates of deposit		1
Period from inception to maturity		12 months