INCOME TAXES - Company's Income Tax Expense (Details 2) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
INCOME TAXES
Computed expected income tax expense			$ 13,820,000	$ 8,336,000
State income taxes, net of federal tax benefit			2,120,000	1,027,000
Permanent differences, net			(2,955,000)	(2,265,000)
Other, net			(185,000)	(101,000)
Income tax expense	$ 7,939,000	$ 5,104,000	$ 12,800,000	$ 6,997,000