Long-Term Debt (Credit Facility Narrative) (Details) (USD $)	3 Months Ended				1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Revolving Credit Facility [Member] 2011 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] 2011 Revolving Credit Facility [Member] Eurodollar [Member]	Jul. 31, 2013 Revolving Credit Facility [Member] 2011 Revolving Credit Facility [Member] Eurodollar [Member] Minimum [Member]	Jul. 31, 2013 Revolving Credit Facility [Member] 2011 Revolving Credit Facility [Member] Eurodollar [Member] Maximum [Member]	Feb. 06, 2014 Subsequent Event [Member] Revolving Credit Facility [Member] 2011 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding credit facility			$ 945,000,000
Revolving credit facility, term			5 years
Maximum borrowing capacity			1,100,000,000.0
Credit facility variable rate				Eurodollar
Credit facility basis spread on variable rate					2.00%	2.50%
Interest rate at period end			2.80%
Repayments of credit facility							90,000,000
Proceeds from credit facility	340,000,000	240,000,000					0
Amount of accordion feature remaining			200,000,000
Maximum borrowing capacity, including accordion feature			$ 1,300,000,000