Goodwill And Intangible Assets, Net (Changes In Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Goodwill [Roll Forward]
Beginning balance	$ 2,309.4	$ 2,323.0
Additions and other adjustments		(2.5)
Currency translation adjustments	29.0	(11.1)
Ending balance	2,338.4	2,309.4
Employer Services
Goodwill [Roll Forward]
Beginning balance	2,304.6	2,318.2
Additions and other adjustments		(2.5)
Currency translation adjustments	29.0	(11.1)
Ending balance	2,333.6	2,304.6
PEO Services
Goodwill [Roll Forward]
Beginning balance	4.8	4.8
Additions and other adjustments		0.0
Currency translation adjustments	0.0	0.0
Ending balance	$ 4.8	$ 4.8