CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Oct. 31, 2019	Apr. 30, 2019
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts	$ 23,165	$ 21,582
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	73,120,000	72,442,000
Common stock, shares outstanding	55,315,000	56,431,000