Supplementary Information On Oil, Ngl And Natural Gas Reserves (Summary of Net Quantities of Proved, Developed and Undeveloped Oil and Natural Gas Reserves) (Details)	12 Months Ended
	Sep. 30, 2015 Mcf bbl	Sep. 30, 2014 Mcf bbl	Sep. 30, 2013 Mcf bbl
Oil [Member]
Reserve Quantities [Line Items]
Proved Oil and Natural Gas Reserves, Beginning Balance	7,569,579	1,643,303	1,072,319
Revisions of previous estimates	(1,697,309)	(50,025)	(90,968)
Acquisitions (divestitures)		5,882,886
Extensions and discoveries and other additions	1,619,285	439,802	896,036
Production	(453,125)	(346,387)	(234,084)
Proved Oil and Natural Gas Reserves, Ending Balance	7,038,430	7,569,579	1,643,303
Natural Gas Liquids [Member]
Reserve Quantities [Line Items]
Proved Oil and Natural Gas Reserves, Beginning Balance	3,040,181	1,616,126	788,742
Revisions of previous estimates	(425,300)	469,897	141,081
Acquisitions (divestitures)		884,889
Extensions and discoveries and other additions	516,679	276,957	798,200
Production	(210,960)	(207,688)	(111,897)
Proved Oil and Natural Gas Reserves, Ending Balance	2,920,600	3,040,181	1,616,126
Natural Gas [Member]
Reserve Quantities [Line Items]
Proved Oil and Natural Gas Reserves, Beginning Balance | Mcf	142,492,360	132,289,167	113,514,056
Revisions of previous estimates | Mcf	(31,273,207)	(3,917,380)	(2,697,853)
Acquisitions (divestitures) | Mcf		8,191,448	1,660,649
Extensions and discoveries and other additions | Mcf	18,740,114	16,702,684	30,698,644
Production | Mcf	(9,745,223)	(10,773,559)	(10,886,329)
Proved Oil and Natural Gas Reserves, Ending Balance | Mcf	120,214,044	142,492,360	132,289,167