XML 68 R64.htm IDEA: XBRL DOCUMENT v2.4.1.9
Acquisition and Dispositions of Properties - Additional Information (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 12 Months Ended 1 Months Ended
Mar. 31, 2015
Dec. 31, 2014
MBoe
Oct. 31, 2014
acre
Gas and Oil Acreage [Line Items]      
Proved developed reserves (Energy)   69,038us-gaap_ProvedDevelopedReservesBOE1  
Payment for unproved leasehold $ 30.7egn_PaymentsToAcquireUnprovedLeaseholdProperties $ 68.5egn_PaymentsToAcquireUnprovedLeaseholdProperties  
San Juan      
Gas and Oil Acreage [Line Items]      
Acres of unproved leasehold, net     15,000us-gaap_GasAndOilAreaUndevelopedNet
/ us-gaap_StatementGeographicalAxis
= country_PR
Payment for unproved leasehold     22.8egn_PaymentsToAcquireUnprovedLeaseholdProperties
/ us-gaap_StatementGeographicalAxis
= country_PR
San Juan Basin      
Gas and Oil Acreage [Line Items]      
Amount of consideration received 395us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= egn_SanJuanBasinMember
   
Purchase price adjustments 11egn_DisposalGroupNotDiscontinuedOperationPurchasePriceAdjustments
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= egn_SanJuanBasinMember
   
Pre-tax proceeds 384us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= egn_SanJuanBasinMember
   
Transaction costs 2.8egn_DisposalGroupNotDiscontinuedOperationTransactionCosts
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= egn_SanJuanBasinMember
   
San Juan Basin | San Juan      
Gas and Oil Acreage [Line Items]      
Pre-tax gain on disposal $ 28.1us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= egn_SanJuanBasinMember
/ us-gaap_StatementGeographicalAxis
= country_PR