Acquisitions (Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Goodwill	$ 1,719.3	$ 1,719.3
National Media
Recognized amounts of identifiable assets acquired and liabilities assumed
Goodwill	1,602.7	$ 1,602.7	$ 1,862.8
2020 Fiscal Year Acquisitions | National Media
Consideration
Cash	24.2
Payment in escrow	0.9
Contingent consideration arrangement	4.1
Fair value of total consideration transferred	29.2
Recognized amounts of identifiable assets acquired and liabilities assumed
Total identifiable assets acquired	23.3
Total liabilities assumed	(0.8)
Total identified net assets	22.5
Goodwill	6.7
Fair value of total consideration transferred	$ 29.2