Commitments and Contingencies (Details) (Acreage in the Eagle Ford shale play in South Texas, USD $) In Millions, unless otherwise specified	3 Months Ended
Sep. 30, 2012 A
Acreage in the Eagle Ford shale play in South Texas
Litigations
Percentage of overriding royalty interest in production (as a percent)	7.46875%
Acres of land for which an overriding royalty interest is claimed (in acres)	22,000
Damages sought	$ 5.1

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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