Supplementary Information For Oil And Gas Producing Activities (Costs Incurred In Oil And Gas Property Acquisition, Exploration And Development Activities) (Details) (USD $)	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Supplementary Information For Oil And Gas Producing Activities Unaudited [Abstract]
Proved	$ 18,213,000		$ 7,575,000		$ 13,095,000
Unproved	7,884,000		9,274,000		13,867,000
Exploration Costs	71,850,000	[1]	49,483,000	[1]	84,624,000	[1]
Development Costs	490,164,000	[2]	460,554,000	[2]	576,397,000	[2]
Asset Retirement Costs	(4,946,000)		37,546,000		10,344,000
Total Property Acquisition Costs	583,165,000		564,432,000		698,327,000
Capitalized interest included in exploration costs	700,000		400,000		1,000,000
Capitalized interest included in development costs	$ 700,000		$ 700,000		$ 2,000,000

[1] Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.4 million and $1.0 million, respectively.

[2] Amounts for 2014, 2013 and 2012 include capitalized interest of $0.7 million, $0.7 million and $2.0 million, respectively.