Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Sep. 30, 2011
Line of Credit Facility [Line Items]
Outstanding credit facility	$ 250,000	$ 200,000
Long-term debt	520,000	520,000
2011 Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding credit facility	$ 520,000	$ 520,000
Market adjustable interest rate (per annum)	3.10%	3.10%