Debt (Details) - USD ($)	Jun. 30, 2015	Aug. 12, 2014
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 15,000,000
Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	233,600,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 1,400,000
Credit Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 250,000,000
Credit Agreement [Member] | Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		40,000,000
Credit Agreement [Member] | Swing Line Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 25,000,000