Long-term Debt (Details) - USD ($)	3 Months Ended
	Sep. 30, 2016	Jun. 30, 2016
Debt Instrument [Line Items]
Total long-term debt	$ 698,750,000	$ 695,000,000
Unamortized debt issuance costs	(1,348,000)	(1,494,000)
Current portion of long-term debt	(75,000,000)	(75,000,000)
Long-term debt	$ 622,402,000	618,506,000
Subordinated note receivable, interest rate	3.50%
Line of Credit [Member] | Asset Backed Bank Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 80,000,000	80,000,000
Line of credit facility, maximum borrowing capacity	100,000,000	100,000,000
Accounts receivable outstanding under the revolving agreement	169,100,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	50,000,000	40,000,000
Line of credit facility, maximum borrowing capacity	200,000,000	200,000,000
Term Loan Facility [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	218,750,000	225,000,000
Senior Notes [Member] | Senior Notes 3.04% due 2017 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 50,000,000	$ 50,000,000
Debt instrument, stated interest rate	3.04%	3.04%
Senior Notes [Member] | Senior Notes 3.04% due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 50,000,000	$ 50,000,000
Debt instrument, stated interest rate	3.04%	3.04%
Senior Notes [Member] | Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 100,000,000	$ 100,000,000
Senior Notes [Member] | Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 150,000,000	$ 150,000,000