CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Jul. 31, 2015	Jan. 31, 2015	Jul. 31, 2014
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts and sales discounts on accounts receivable (in dollars)	$ 54,213	$ 53,441	$ 41,542
Preferred stock, shares authorized	1,000,000	1,000,000	1,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	120,000,000	120,000,000	120,000,000
Common stock, shares issued	46,204,474	45,941,644	45,754,916
Treasury stock, shares	984,450	984,450	984,450