Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Oct. 31, 2012	Jan. 31, 2012	Oct. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts and sales discounts	$ 46,649	$ 34,436	$ 36,129
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	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000	80,000,000
Common stock, shares issued	20,590,520	20,279,132	20,259,922
Treasury stock, shares	492,225	492,225	492,225