Goodwill And Intangible Assets, Net (Changes In Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2015
Goodwill [Roll Forward]
Beginning balance	$ 1,682.0	$ 1,793.5	[1]
Transfer of goodwill		0.0
Currency translation adjustments	7.0	(11.1)
Additions and other adjustments	73.4
Disposition of business	(21.4)	(100.4)
Ending balance	1,741.0	1,682.0
Accumulated impairment loss				$ 42.7
Employer Services [Member]
Goodwill [Roll Forward]
Beginning balance	1,677.2	1,788.7	[1]
Transfer of goodwill		(100.4)
Currency translation adjustments	7.0	(11.1)
Additions and other adjustments	73.4
Disposition of business	(21.4)	0.0
Ending balance	1,736.2	1,677.2
PEO Services [Member]
Goodwill [Roll Forward]
Beginning balance	4.8	4.8	[1]
Transfer of goodwill		0.0
Currency translation adjustments	0.0	0.0
Additions and other adjustments	0.0
Disposition of business	0.0	0.0
Ending balance	4.8	4.8
Other Segments [Member]
Goodwill [Roll Forward]
Beginning balance	0.0	0.0	[1]
Transfer of goodwill		100.4
Currency translation adjustments	0.0	0.0
Additions and other adjustments	0.0
Disposition of business	0.0	(100.4)
Ending balance	$ 0.0	$ 0.0

[1] The goodwill balance at June 30, 2015 is net of accumulated impairment losses of $42.7 million related to the Employer Services segment.