Debt and Financing Arrangements (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Line of Credit Facility [Line Items]
Standby letters of credit outstanding		$ 4,200,000		$ 4,200,000
Revolving Credit Facility | Line of Credit | Amended Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 250,000,000.0
Commitment fee percentage	0.375%
Commitment fees incurred		200,000	$ 0	600,000	$ 200,000
Debt issuance costs	$ 900,000
Covenant, minimum level of liquidity required		$ 125,000,000.0		125,000,000.0
Revolving Credit Facility | Line of Credit | Amended Credit Agreement | Minimum
Line of Credit Facility [Line Items]
Covenant, minimum level of revenue required				725,000,000.0
Revolving Credit Facility | Line of Credit | Amended Credit Agreement | Maximum
Line of Credit Facility [Line Items]
Covenant, minimum level of revenue required				$ 1,985,000,000.0
Revolving Credit Facility | Line of Credit | Amended Credit Agreement | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.75%
Revolving Credit Facility | Line of Credit | Amended Credit Agreement | Alternative Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.75%
Letter of Credit | Line of Credit | Amended Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity (or less)	$ 150,000,000.0