EARNINGS (LOSS) PER SHARE AND STOCKHOLDERS' EQUITY (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	5,100	3,700	5,100	3,700
Basic weighted average common shares (in shares)	189,607	198,079	191,103	200,058
Nonvested units granted (in shares)			2,100
Stock-based compensation	$ 7.3	$ 9.4	$ 14.9	$ 16.1
Unrecognized compensation costs, nonvested shares and units	$ 47.3		$ 47.3