Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2016	Jan. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, receivables	$ 5,225	$ 7,793
Accumulated depreciation	$ 152,516	$ 143,782
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	65,333,010	64,998,368
Treasury stock, shares	12,803,134	13,137,776