Supplementary Information On Oil, Ngl And Natural Gas Reserves (Summary of Proved Undeveloped Reserves) (Details)	12 Months Ended
	Sep. 30, 2013 Mcfe
Supplementary Information On Oil, Ngl And Natural Gas Reserves [Abstract]
Beginning proved undeveloped reserves	50,885,055
Proved undeveloped reserves transferred to proved developed	(12,124,203)
Revisions	(14,309,809)
Extensions and discoveries	32,806,004
Purchases	1,477,609
Ending proved undeveloped reserves	58,734,656