Supplemental Information Relating to Oil and Natural Gas Producing Activities (Unaudited) - Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities (Details) (Compass)	7 Months Ended		12 Months Ended
	Sep. 30, 2013 MBbls		Sep. 30, 2014 MBbls		Feb. 14, 2013 MBbls
Oil
Proved Developed and Undeveloped Reserves [Abstract]
Beginning of period			3,424,000
Purchase of reserves in place	3,940,000	[1]
Discoveries and extensions	188,000	[2]	112,000	[2]
Changes in price	(125,000)		233,000
Other factors	(296,000)	[3]	335,000	[4]
Production	(283,000)	[3]	(414,000)
Enf of period	3,424,000		3,690,000
Proved Developed and Undeveloped Reserve (Energy) [Roll Forward]
Proved Developed Reserves (Volume)			3,356,000		3,107,000
Proved Undeveloped Reserve (Volume)			334,000		317,000
Natural Gas
Proved Developed and Undeveloped Reserves [Abstract]
Beginning of period			322,418,000
Purchase of reserves in place	331,592,000	[1]
Discoveries and extensions	4,416,000	[2]	839,000	[2]
Changes in price	13,116,000		20,815,000
Other factors	(12,136,000)	[3]	(13,750,000)	[4]
Production	(14,570,000)	[3]	(20,882,000)
Enf of period	322,418,000		309,440,000
Proved Developed and Undeveloped Reserve (Energy) [Roll Forward]
Beginning of period			377,342,000
Purchase of reserves in place (1)	399,350,000	[1]
Discoveries and extensions (2)	10,062,000	[2]	2,549,000	[2]
Changes in price	11,556,000		25,189,000
Proved Developed and Undeveloped Reserves, Revisions of Previous Estimates (Energy), Other Factors	(25,558,000)	[3]	(9,688,000)	[4]
Production	(18,068,000)	[3]	(26,492,000)
End of period	377,342,000		368,900,000
Proved Developed Reserves (Volume)			304,628,000		317,748,000
Proved Undeveloped Reserve (Volume)			4,812,000		4,670,000
Natural Gas Liquids
Proved Developed and Undeveloped Reserves [Abstract]
Beginning of period			5,730,000
Purchase of reserves in place	7,353,000	[1]
Discoveries and extensions	753,000	[2]	173,000	[2]
Changes in price	(135,000)		496,000
Other factors	(1,941,000)	[3]	342,000	[4]
Production	(300,000)	[3]	(521,000)
Enf of period	5,730,000		6,220,000
Proved Developed and Undeveloped Reserve (Energy) [Roll Forward]
Proved Developed Reserves (Volume)			5,145,000		4,799,000
Proved Developed Reserves (Energy)			355,634,000		365,185,000
Proved Undeveloped Reserve (Volume)			1,075,000		931,000
Proved Undeveloped Reserves (Energy)			13,266,000		12,157,000
Permian Basin
Proved Developed and Undeveloped Reserve (Energy) [Roll Forward]
Proved Developed and Undeveloped Reserves, Revisions of Previous Estimates (Energy), Other Factors	18,100,000,000
East Texas/North Louisiana
Proved Developed and Undeveloped Reserve (Energy) [Roll Forward]
Proved Developed and Undeveloped Reserves, Revisions of Previous Estimates (Energy), Other Factors	7,500,000,000.0		11.5

[1] Purchases of reserves in place include the initial contribution of conventional assets from EXCO as of February 14, 2013, and the acquisition of shallow Cotton Valley assets from an affiliate of BG Group as of March 5, 2013.

[2] New discoveries and extensions were a result of Compass’ development in the Permian basin for both Fiscal 2014 and the period from inception to September 30, 2013.

[3] Revisions of previous estimates due to other factors were primarily due to downward adjustments in the Permian basin of 18.1 Bcfe as a result of recent performance and modifications to Compass’ development plans which extended the development beyond a five-year horizon. In addition, revisions of previous estimates due to other factors in the East Texas/North Louisiana region were 7.5 Bcfe primarily due to performance.

[4] (4) Revisions of previous estimates due to other factors were primarily due to downward adjustments in the East Texas/North Louisiana region of 11.5 Bcfe primarily due to recent performance.