Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 25, 2015	Jan. 25, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, receivables	$ 5,554	$ 3,523
Accumulated depreciation	$ 137,962	$ 120,588
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	78,136,144	78,136,144
Common stock, shares outstanding	64,853,598	66,812,919
Treasury stock, shares	13,282,546	11,323,225