Fair Value Measurements - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jun. 30, 2019
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Broadcast rights payable	$ 22.4	$ 15.0
Total long-term debt	2,355.9	2,333.3
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Broadcast rights payable	21.1	13.6
Total long-term debt	$ 2,457.0	$ 2,452.9