Long-Term Debt (Details) - USD ($)	Feb. 14, 2012	Sep. 30, 2020	Jun. 30, 2020	Jun. 07, 2018
Long-Term Debt (Additional Textual) [Abstract]
Fixed rate at fair market value		$ 643,400,000	$ 630,200,000
ThreePointEightSevenFivePercentSeniorUnsecuredNotesDueInTwoThousandAndTwentyTwo [Member]
Long-Term Debt (Additional Textual) [Abstract]
Proceeds from Issuance of Senior Long-term Debt	$ 300,000,000
Debt Instrument, Interest Rate, Stated Percentage		3.875%
2018 Credit Agreement [Member]
Long-Term Debt (Textual) [Abstract]
Line of Credit Facility, Remaining Borrowing Capacity		$ 661,500,000
Borrowing outstanding under 2018 Credit Agreement		38,500,000	$ 500,000,000.0
Line of Credit Facility, Maximum Borrowing Capacity				$ 700,000,000.0
Line of Credit [Member]
Long-Term Debt (Textual) [Abstract]
Amended Net Debt to EBITDA Ratio, allowable adjustment for cash restructuring charges, amount		120,000,000
Amended Net Debt to EBITDA Ratio, Maximum		4.25
Consolidated Interest Coverage Ratio, Minimum		3.5
Net Debt to EBITDA Ratio, allowable adjustment for cash restructuring charges, amount		80,000,000
Net Debt to EBITDA Ratio, Maximum		3.5
Net Debt to EBITDA Ratio, domestic cash allowed to net debt, amount, minimum		$ 25,000,000