Fair Value Measurements (Schedule of Carrying Value and Estimated Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jun. 30, 2018
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Broadcast rights payable	$ 15.0	$ 29.7
Long-term debt	2,333.3	3,135.6
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Broadcast rights payable	13.6	27.4
Long-term debt	$ 2,452.9	$ 3,179.8