Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2016	Jan. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable and sales returns	$ 45,851	$ 45,875
Common stock, par value	$ 0.0015	$ 0.0015
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	59,245,585	59,245,585
Treasury stock, shares	24,048,956	24,163,402