Debt Debt (Details) - USD ($)	3 Months Ended	6 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Long-term Debt Instruments [Line Items]
Letters of Credit Outstanding, Amount	$ 3,788,000	$ 3,788,000		$ 2,698,000
Long-term debt repayments		34,868,000	$ 151,868,000
Debt Issuance Costs, Gross, Current	593,000	593,000		577,000
Debt Issuance Cost, Gross, Noncurrent	1,174,000	1,174,000		1,366,000
Revolving Credit Facility [Member]
Long-term Debt Instruments [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	250,000,000	250,000,000
Letters of Credit Outstanding, Amount	1,776,000	1,776,000		3,215,000
Line of Credit Facility, Remaining Borrowing Capacity	248,224,000	$ 248,224,000		246,785,000
Revolving Credit Facility [Member] | Minimum [Member]
Long-term Debt Instruments [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.10%
Revolving Credit Facility [Member] | Maximum [Member]
Long-term Debt Instruments [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.20%
Long-term Debt [Member]
Long-term Debt Instruments [Line Items]
Debt Instrument, Face Amount	780,000,000	$ 780,000,000
Long-term Debt	$ 603,875,000	$ 603,875,000		$ 613,625,000
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	3.56%	3.56%		4.19%
Asset-backed Securities, Securitized Loans and Receivables [Member]
Long-term Debt Instruments [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.61%	2.61%		3.33%
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement	$ 175,000,000	$ 175,000,000
Debt Instrument, Fee	0.0090	0.0090
Prudential Facility [Domain]
Long-term Debt Instruments [Line Items]
Debt Instrument, Face Amount	$ 170,000,000	$ 170,000,000
Prudential Facility [Domain] | Minimum [Member]
Long-term Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.25%	0.25%
Prudential Facility [Domain] | Maximum [Member]
Long-term Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.25%	1.25%
Prudential Facility - Series C [Member]
Long-term Debt Instruments [Line Items]
Long-term Debt	$ 120,000,000	$ 120,000,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	3.19%	3.19%
Prudential Facility - Series D [Member]
Long-term Debt Instruments [Line Items]
Long-term Debt	$ 50,000,000	$ 50,000,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	3.21%	3.21%
Long-term debt repayments	$ 25,000,000
Prudential Facility - Series E [Member] [Member]
Long-term Debt Instruments [Line Items]
Long-term Debt	$ 25,000,000	$ 25,000,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	3.08%	3.08%
State of Ohio Assumed Debt [Member]
Long-term Debt Instruments [Line Items]
Debt Instrument, Face Amount	$ 2,359,000	$ 2,359,000
Long-term Debt	$ 1,086,000	$ 1,086,000		$ 1,204,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	1.50%	1.50%