Long-term Debt - Schedule of Long-Term Debt (Details) - USD ($)	Dec. 31, 2019	Jun. 30, 2019
Principal Balance
Principal balance of long-term debt, including current maturities	$ 2,390,400,000	$ 2,370,400,000
Unamortized Discount and Debt Issuance Costs
Unamortized discount and debt issuance costs, including current maturities	(34,500,000)	(37,100,000)
Carrying Value
Long-term debt, including current maturities	2,355,900,000	2,333,300,000
Senior Notes | 6.875% senior notes, due 2/1/2026
Principal Balance
Principal balance of long-term debt, including current maturities	1,272,900,000	1,272,900,000
Unamortized Discount and Debt Issuance Costs
Unamortized discount and debt issuance costs, including current maturities	(20,100,000)	(21,500,000)
Carrying Value
Long-term debt, including current maturities	$ 1,252,800,000	$ 1,251,400,000
Debt instrument, stated interest rate	6.875%	6.875%
Variable-rate credit facilities | Line of Credit | Senior credit facility term loan, due 1/31/2025
Principal Balance
Principal balance of long-term debt, including current maturities	$ 1,062,500,000	$ 1,062,500,000
Unamortized Discount and Debt Issuance Costs
Unamortized discount and debt issuance costs, including current maturities	(14,400,000)	(15,600,000)
Carrying Value
Long-term debt, including current maturities	1,048,100,000	1,046,900,000
Variable-rate credit facilities | Line of Credit | Revolving credit facility of $350 million, due 1/31/2023
Principal Balance
Principal balance of long-term debt, including current maturities	55,000,000.0	35,000,000.0
Unamortized Discount and Debt Issuance Costs
Unamortized discount and debt issuance costs, including current maturities	0	0
Carrying Value
Long-term debt, including current maturities	55,000,000.0	35,000,000.0
Line of credit facility, maximum borrowing capacity	$ 350,000,000	$ 350,000,000