Indebtedness (Details) (USD $)	0 Months Ended	9 Months Ended		55 Months Ended		60 Months Ended
	Nov. 06, 2012	Jul. 07, 2013	Jul. 08, 2012	Nov. 05, 2017	Nov. 05, 2012	Nov. 05, 2017 Maximum [Member]	Nov. 05, 2017 Minimum [Member]	Nov. 05, 2012 Initial Interest Rate [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 400,000,000
Proceeds from issuance of debt	200,000,000	200,000,000	0
Letters of credit maximum issuance available		75,000,000
Debt instrument, periodic payment, principal				5,000,000
Proceeds from lines of credit	220,000,000
Line of Credit Facility, Amount Outstanding		185,000,000
Loans Payable to Bank		190,000,000			200,000,000
Debt Instrument, Basis Spread on Variable Rate						2.25%	1.75%
Debt Instrument, Initial Interest Rate								2.00%
Letters of Credit Outstanding, Amount		$ 29,100,000