FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands		Apr. 30, 2016	Jan. 31, 2016	Apr. 30, 2015	Jan. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability related to interest rate swap		$ (706)	$ (675)
Cash and cash equivalents deposited with commercial banks		139,878	137,731	$ 130,864	$ 120,526
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents deposited with commercial banks		27,000	24,000
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market mutual funds	[1]	112,792	113,984
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability related to interest rate swap	[2]	$ (705)	$ (675)

[1] Money market mutual funds are recorded at fair value based upon quoted market prices.

[2] The liability related to the interest rate swap is recorded at fair value based upon a valuation model that uses relevant observable market inputs at quoted intervals, such as forward yield curves.