Supplemental Information Relating to Oil and Natural Gas Producing Activities (Unaudited) - Costs Incurred in Oil and Gas Property Acquisiton, Exploration, and Development (Details) (EXCO/HGI JV, USD $) In Millions, unless otherwise specified	7 Months Ended
	Sep. 30, 2013
EXCO/HGI JV
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Proved property acquisition costs	$ 569.5
Unproved property acquisition costs	53.9
Total property acquisition costs	623.4
Development	11.8
Exploration costs	0
Lease acquisitions and other	0
Capitalized asset retirement costs	$ 0.1
Depreciation, depletion and amortization per unit	1.72