Long-Term Debt (Bank Credit Facility) (Narrative) (Details) (USD $)	3 Months Ended		3 Months Ended		3 Months Ended			3 Months Ended				3 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2012 Bank Credit Facility [Member]	Oct. 21, 2010 Bank Credit Facility [Member]	Sep. 30, 2012 Revolving Credit Facility [Member]	Sep. 30, 2012 Revolving Credit Facility [Member] Bank Credit Facility [Member]	Oct. 21, 2010 Revolving Credit Facility [Member] Bank Credit Facility [Member]	Sep. 30, 2012 Term Loan [Member]	Oct. 21, 2010 Term Loan [Member] Bank Credit Facility [Member]	Oct. 21, 2010 Same-Day Swing Line Loan [Member] Bank Credit Facility [Member]	Oct. 21, 2010 Stand-By Letters Of Credit [Member] Bank Credit Facility [Member]	Sep. 30, 2012 Principal Payment Through September 30, 2015 [Member] Term Loan [Member] Bank Credit Facility [Member]	Sep. 30, 2012 Principal Payment From October 1, 2015 Through September 30, 2016 [Member] Term Loan [Member] Bank Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, amount outstanding	$ 263,000,000	$ 125,000,000				$ 263,000,000
Credit facility maximum borrowing capacity				750,000,000			600,000,000		150,000,000	50,000,000	25,000,000
Loan maturity date					Nov. 18, 2016			Nov. 18, 2016
Term loan period	5 years
Term loan principal payment												1,900,000	3,800,000
Term loan maximum additional borrowing capacity			150,000,000
Outstanding borrowings under the Credit Facility, percentage			1.73%
Debt issuance cost capitalized			7,300,000
Unamortized balance included in other assets			$ 4,700,000