COMPUTATION OF NET INCOME PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	$ 5,090	$ 2,049	$ 5,999	$ 2,040
Less: Dividends declared	(1,118)	(1,090)	(3,334)	(3,267)
Undistributed net income (loss)	3,972	959	2,665	(1,227)
Net income per share [Abstract]
Dividends declared	1,118	1,090	3,334	3,267
Undistributed net income (loss)	3,972	959	2,665	(1,227)
Net income attributable to common stock	5,090	2,049	5,999	2,040
Common Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	4,218	1,694	4,971	1,688
Less: Dividends declared	(926)	(901)	(2,761)	(2,700)
Undistributed net income (loss)	3,292	793	2,210	(1,012)
Net income per share [Abstract]
Dividends declared	926	901	2,761	2,700
Undistributed net income (loss)	3,292	793	2,210	(1,012)
Net income attributable to common stock	4,218	1,694	4,971	1,688
Weighted average shares of common stock outstanding-basic (in shares)	12,865	12,526	12,755	12,477
Weighted average potential shares of common stock (in shares)	622	464	719	453
Weighted average shares of common stock and potential common shares outstanding-diluted (in shares)	13,487	12,990	13,474	12,930
Basic net income per common share (in dollars per share)	$ 0.33	$ 0.14	$ 0.39	$ 0.14
Diluted net income per common share (in dollars per share)	$ 0.31	$ 0.13	$ 0.37	$ 0.13
Antidilutive securities excluded from computation of net income (loss) per share (in shares)	330	1,307	277	1,148
Common Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	872	355	1,028	352
Less: Dividends declared	(192)	(189)	(573)	(567)
Undistributed net income (loss)	680	166	455	(215)
Net income per share [Abstract]
Dividends declared	192	189	573	567
Undistributed net income (loss)	680	166	455	(215)
Net income attributable to common stock	$ 872	$ 355	$ 1,028	$ 352
Weighted average shares of common stock outstanding-basic (in shares)	3,189	3,149	3,180	3,146
Weighted average potential shares of common stock (in shares)	76	86	90	88
Weighted average shares of common stock and potential common shares outstanding-diluted (in shares)	3,265	3,235	3,270	3,234
Basic net income per common share (in dollars per share)	$ 0.27	$ 0.11	$ 0.32	$ 0.11
Diluted net income per common share (in dollars per share)	$ 0.27	$ 0.11	$ 0.31	$ 0.11
Antidilutive securities excluded from computation of net income (loss) per share (in shares)	67	189	38	183