Goodwill and Intangible Assets, net - Changes In Goodwill (Details) $ in Millions	9 Months Ended
	Mar. 31, 2022 USD ($)
Goodwill [Roll Forward]
Balance at June 30, 2021	$ 2,338.4
Additions and other adjustments	11.1
Currency translation adjustments	(25.4)
Balance at March 31, 2022	2,324.1
Employer Services
Goodwill [Roll Forward]
Balance at June 30, 2021	2,333.6
Additions and other adjustments	11.1
Currency translation adjustments	(25.4)
Balance at March 31, 2022	2,319.3
PEO Services
Goodwill [Roll Forward]
Balance at June 30, 2021	4.8
Additions and other adjustments	0.0
Currency translation adjustments	0.0
Balance at March 31, 2022	$ 4.8