CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Oct. 31, 2013	Jan. 31, 2013	Oct. 31, 2012
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 10,456	$ 9,710	$ 8,796
Preferred Stock, par value	$ 0.01	$ 0.01	$ 0.01
Preferred Stock, shares authorized	2,000	2,000	2,000
Preferred Stock, shares issued
Preferred Stock, shares outstanding
Common Stock, par value	$ 0.01	$ 0.01	$ 0.01
Common Stock, shares authorized	240,000	240,000	240,000
Common Stock, shares issued	128,048	126,934	126,744
Common Stock, shares outstanding	128,048	126,934	126,744