Concentrations of Credit Risk (Details)	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Concentrations of Credit Risk
Sales of gas, oil and condensate production contract term, less than	12 months
Net revenue | Major Customers | Plains Marketing L.P.
Concentrations of Credit Risk
Percent of Total Revenue	90.00%	84.00%	60.00%
Net revenue | Major Customers | Enterprise Crude Oil LLC
Concentrations of Credit Risk
Percent of Total Revenue	4.00%	7.00%	15.00%
Net revenue | Major Customers | Flint Hills
Concentrations of Credit Risk
Percent of Total Revenue	2.00%	1.00%
Net revenue | Major Customers | DCP Midstream, LP
Concentrations of Credit Risk
Percent of Total Revenue	1.00%	2.00%	6.00%
Net revenue | Major Customers | Kinder Morgan (fka Copano Field Services/Upper Gulf Coast, L.P. )
Concentrations of Credit Risk
Percent of Total Revenue	1.00%	3.00%	7.00%
Net revenue | Major Customers | Enervest LLC
Concentrations of Credit Risk
Percent of Total Revenue	1.00%
Net revenue | Major Customers | Orion Exploration Partners, LLC
Concentrations of Credit Risk
Percent of Total Revenue	1.00%
Net revenue | Major Customers | ETC Texas Pipeline, LTD.
Concentrations of Credit Risk
Percent of Total Revenue		3.00%	12.00%