Long-term Debt (Details) - USD ($)	6 Months Ended
	Dec. 31, 2015	Jun. 30, 2015
Debt Instrument [Line Items]
Total long-term debt	$ 798,750,000	$ 795,000,000
Current portion of long-term debt	(68,750,000)	(62,500,000)
Long-term debt	$ 730,000,000	732,500,000
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
Accounts receivable outstanding under the revolving agreement	182,800,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	87,500,000	77,500,000
Line of credit facility, maximum borrowing capacity	200,000,000
Term Loan Facility [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Total long-term debt	231,250,000	237,500,000
Senior Notes [Member] | Senior Notes 3.04% due 2016 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 50,000,000	50,000,000
Debt instrument, stated interest rate	3.04%
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%
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%
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