Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Financial Instruments and Balance Sheet Classifications (Parenthetical) (Detail)

v3.21.2
Financial Instruments - Financial Instruments and Balance Sheet Classifications (Parenthetical) (Detail) - USD ($)
$ in Millions
3 Months Ended
Jul. 31, 2021
Jul. 31, 2020
Apr. 30, 2021
Investments Debt And Equity Securities [Abstract]      
Obligations for which assets are held in trust $ 171.2   $ 157.3
Gain on marketable securities 5.2 $ 11.5  
Unvested obligations under deferred compensation plans $ 24.7   $ 26.5