Consolidated Balance Sheets (Parenthetical) - $ / shares	Oct. 29, 2016	Apr. 30, 2016	Oct. 31, 2015
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Common stock, shares authorized	300,000,000	300,000,000	300,000,000
Common stock, shares issued	111,560,000	111,228,000	110,595,000
Treasury stock, shares	39,741,000	37,941,000	34,961,000