Derivative Financial Instruments Derivative Financial Instruments - Oil and Gas Commodity Contracts (Details) bbl in Thousands, MMBTU in Thousands, MBbls in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2015 USD ($) MMBTU $ / MMBTU $ / bbl MBbls	Dec. 31, 2014	Sep. 30, 2015 MMBTU bbl
Derivative [Line Items]
Derivative, Percentage of Production Volume Covered by Derivative Financial Instruments	60.00%	71.00%
Natural Gas Commodity Contract [Member]
Derivative [Line Items]
Natural Gas, Volume | MMBTU	3,350,000
Fair Value at December 31, 2015	$ (0.2)
Oil Commodity Contract [Member]
Derivative [Line Items]
Fair Value at December 31, 2015	$ 1.5
Derivative, Commodity Contract, Oil Volume | MBbls	183
Swap [Member] | Natural Gas Commodity Contract [Member]
Derivative [Line Items]
Natural Gas, Volume | MMBTU			3,380
Swap [Member] | Oil Commodity Contract [Member]
Derivative [Line Items]
Derivative, Commodity Contract, Oil Volume | bbl			273
Swap [Member] | Energy Related Derivative [Member]
Derivative [Line Items]
Fair Value at December 31, 2015	$ 1.3
Collar [Member] | Natural Gas Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Fair Value at December 31, 2015	$ 1.5
Collar [Member] | Oil Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Derivative, Commodity Contract, Oil Volume | MBbls	183
Three-way collar [Member] | Natural Gas Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Natural Gas, Volume | MMBTU	3,350,000
Fair Value at December 31, 2015	$ (0.2)
Three-way collar [Member] | Natural Gas Commodity Option Contract- Short call [Member] [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Weighted average strike price per Mmbtu/Bbl | $ / MMBTU	2.77
Three-way collar [Member] | Natural Gas Commodity Commodity Contract- Long put [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Weighted average strike price per Mmbtu/Bbl | $ / MMBTU	2.15
Short put [Member] | Collar [Member] | Oil Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Weighted average strike price per Mmbtu/Bbl | $ / bbl	42.00
Long put [Member] | Collar [Member] | Oil Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Weighted average strike price per Mmbtu/Bbl | $ / bbl	56.00
Short call [Member] | Collar [Member] | Oil Commodity Contract [Member] | Remainder of 2014 [Member]
Derivative [Line Items]
Weighted average strike price per Mmbtu/Bbl | $ / bbl	76.00