Goodwill and Intangible Assets, Net of Accumulated Amortization (Change in Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2021	May 31, 2020
Goodwill and Intangible Assets, Net of Accumulated Amortization [Abstract]
Goodwill Balance, beginning of fiscal year	$ 1,791.1	$ 1,782.6
Changes during the period:
Goodwill acquired	19.6	4.1
Acquisition accounting adjustments		4.5
Currency translation adjustment	10.0	(0.1)
Goodwill Balance, end of fiscal year	$ 1,820.7	$ 1,791.1