Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Warrants [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]	Treasury Stock [Member]
Beginning Balance at Jan. 31, 2011	$ 97,645,000	$ 2,040,000	$ 601,000	$ 88,561,000	$ 6,476,000		$ (33,000)
Beginning Balance, Shares, Outstanding at Jan. 31, 2011		13,598,994
Net income	8,970,000				9,272,000	(302,000)
Exercise of stock options	507,000	8,000		499,000
Exercise of stock options, Shares	55,038	55,038
Conversion of stock warrants	23,000	1,000	(11,000)	33,000
Conversion of stock warrants, Shares		3,000
Stock option vesting	637,000			637,000
Reversal of excess tax benefit on forfeited stock options	(16,000)			(16,000)
Dividends	(6,804,000)				(6,804,000)
Other	1,000					1,000
Others, Shares		833
Ending Balance at Jan. 31, 2012	100,963,000	2,049,000	590,000	89,714,000	8,944,000	(301,000)	(33,000)
Ending Balance, Shares, Outstanding at Jan. 31, 2012		13,657,865
Net income	21,817,000				23,265,000	(1,448,000)
Exercise of stock options	1,436,000	23,000		1,413,000
Exercise of stock options, Shares	153,962	153,962
Conversion of stock warrants	1,240,000	24,000	(590,000)	1,806,000
Conversion of stock warrants, Shares		160,000
Stock option vesting	1,316,000			1,316,000
Release of restricted stock	25,000			25,000
Release of restricted stock, Shares		2,500
Excess tax benefit on exercised stock options and converted warrants	730,000			730,000
Dividends	(8,359,000)				(8,359,000)
Ending Balance at Jan. 31, 2013	119,168,000	2,096,000		95,004,000	23,850,000	(1,749,000)	(33,000)
Ending Balance, Shares, Outstanding at Jan. 31, 2013		13,974,327
Net income	43,344,000				40,125,000	3,219,000
Exercise of stock options	3,768,000	46,000		3,722,000
Exercise of stock options, Shares	309,074	309,074
Stock option vesting	1,536,000			1,536,000
Release of restricted stock	26,000	1,000		25,000
Release of restricted stock, Shares		2,500
Excess tax benefit on exercised stock options and converted warrants	576,000			576,000
Dividends	(10,640,000)				(10,640,000)
Deconsolidation of VIEs	(1,000)					(1,000)
Ending Balance at Jan. 31, 2014	$ 157,777,000	$ 2,143,000		$ 100,863,000	$ 53,335,000	$ 1,469,000	$ (33,000)
Ending Balance, Shares, Outstanding at Jan. 31, 2014		14,285,901