Discontinued Operations (Narrative) (Details)	Oct. 31, 2011	Apr. 01, 2011
Rexer Tusa [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Working interest sold		75.00%
Revenue interest percentage sold		54.40%
Rexer [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Working interest sold	25.00%	100.00%
Revenue interest percentage sold	18.40%	72.50%