Debt - Narrative (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Apr. 14, 2023 USD ($)	Dec. 31, 2022	Sep. 30, 2022	Apr. 30, 2022 USD ($)	Mar. 16, 2022 USD ($)	Mar. 26, 2021 USD ($)
Long-term debt outstanding
Aggregate maturities of long-term debt, 2024	$ 0
Aggregate maturities of long-term debt, 2025	0
Aggregate maturities of long-term debt, 2026	0
Aggregate maturities of long-term debt, 2027	0
Aggregate maturities of long-term debt, 2028	0
Interest costs	55,600,000	$ 45,700,000	$ 40,800,000
Interest costs, capitalized	1,500,000	800,000	8,100,000
Debt extinguishment losses, net	$ 0	6,000,000.0	8,200,000
Forward interest rate swaps
Long-term debt outstanding
Derivative, gain on derivative			2,300,000
Letter of Credit
Long-term debt outstanding
Commitment fee rate	0.375%
Letter of credit fees	2.50%
Senior Unsecured Notes 4.45 Percent Due March 2023
Long-term debt outstanding
Long-term debt									$ 300,000,000
Interest rate							4.45%		4.45%
Face amount							$ 300,000,000
Senior unsecured notes, 7.625% due March 2030 (face value of $300.0 million at June 30, 2023 and 2022)
Long-term debt outstanding
Long-term debt	$ 296,500,000	$ 295,900,000
Interest rate	7.625%	7.625%						7.625%
Face amount	$ 300,000,000.0	$ 300,000,000.0						$ 300,000,000
Senior Unsecured Notes 5.20 Percent Due July 2021
Long-term debt outstanding
Debt extinguishment losses, net			$ 10,500,000
Minimum | Letter of Credit
Long-term debt outstanding
Commitment fee rate	0.25%
Letter of credit fees	1.75%
Maximum | Letter of Credit
Long-term debt outstanding
Commitment fee rate	0.375%
Letter of credit fees	2.50%
LIBOR | Letter of Credit
Long-term debt outstanding
Interest rate margin	2.50%
LIBOR | Minimum | Letter of Credit
Long-term debt outstanding
Interest rate margin	1.75%
LIBOR | Maximum | Letter of Credit
Long-term debt outstanding
Interest rate margin	2.50%
Base Rate | Letter of Credit
Long-term debt outstanding
Interest rate margin	1.50%
Base Rate | Minimum | Letter of Credit
Long-term debt outstanding
Interest rate margin	0.75%
Base Rate | Maximum | Letter of Credit
Long-term debt outstanding
Interest rate margin	1.50%
Credit Agreement
Long-term debt outstanding
Credit Agreement available for future borrowings	$ 348,300,000
Short-term credit agreement borrowings	$ 0
Borrowing rate	7.64%
Maximum borrowing capacity									$ 300,000,000
Credit Agreement | Revolving Credit Facility
Long-term debt outstanding
Current borrowing capacity				$ 350,000,000
Required interest coverage ratio one		2.00		3.00
Required consolidated net leverage ratio				4.00
Required interest coverage ratio two					3.50	3.00
Credit Agreement | Revolving Credit Facility | Minimum
Long-term debt outstanding
Credit Agreement available for future borrowings				$ 40,000,000
Credit Agreement | Revolving Credit Facility | Maximum
Long-term debt outstanding
Credit Agreement available for future borrowings				$ 300,000,000
Credit Agreement | Letter of Credit
Long-term debt outstanding
Letters of credit issued	$ 1,700,000