2.2.0.7 true Sheet 00 - Document - Document and Entity Information Document and Entity Information http://nisource.com/role/DocumentAndEntityInformation false R1.xml false Sheet 0110 - Statement - Condensed Statements of Consolidated Income (Loss) (unaudited) Condensed Statements of Consolidated Income (Loss) (unaudited) http://nisource.com/role/StatementsOfIncome false R2.xml false Sheet 0120 - Statement - Condensed Consolidated Balance Sheets (Unaudited) Condensed Consolidated Balance Sheets (Unaudited) http://nisource.com/role/BalanceSheets false R3.xml false Sheet 0121 - Statement - Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) http://nisource.com/role/BalanceSheetsParenthetical false R4.xml false Sheet 0130 - Statement - Condensed Statements of Consolidated Cash Flows (Unaudited) Condensed Statements of Consolidated Cash Flows (Unaudited) http://nisource.com/role/StatementsOfCashFlows false R5.xml false Sheet 0140 - Statement - Condensed Statements of Consolidated Comprehensive Income (unaudited) Condensed Statements of Consolidated Comprehensive Income (unaudited) http://nisource.com/role/StatementsOfComprehensiveIncome false R6.xml false Sheet 0201 - Disclosure - Basis of Accounting Presentation Basis of Accounting Presentation http://nisource.com/role/BasisOfAccountingPresentation false R7.xml false Sheet 0202 - Disclosure - Recent Accounting Pronouncements Recent Accounting Pronouncements http://nisource.com/role/RecentAccountingPronouncements false R8.xml false Sheet 0203 - Disclosure - Earnings Per Share Earnings Per Share http://nisource.com/role/EarningsPerShare false R9.xml false Sheet 0204 - Disclosure - Restructuring Activities Restructuring Activities http://nisource.com/role/RestructuringActivities false R10.xml false Sheet 0205 - Disclosure - Gas in Storage Gas in Storage http://nisource.com/role/GasInStorage false R11.xml false Sheet 0206 - Disclosure - Discontinued Operations and Assets and Liabilities Held for Sale Discontinued Operations and Assets and Liabilities Held for Sale http://nisource.com/role/DiscontinuedOperationsAndAssetsAndLiabilitiesHeldForSale false R12.xml false Sheet 0207 - Disclosure - Asset Retirement Obligations Asset Retirement Obligations http://nisource.com/role/AssetRetirementObligations false R13.xml false Sheet 0208 - Disclosure - Regulatory Matters Regulatory Matters http://nisource.com/role/RegulatoryMatters false R14.xml false Sheet 0209 - Disclosure - Risk Management Activities Risk Management Activities http://nisource.com/role/RiskManagementActivities false R15.xml false Sheet 0210 - Disclosure - Fair Value Disclosures Fair Value Disclosures http://nisource.com/role/FairValueDisclosures false R16.xml false Sheet 0211 - Disclosure - Transfers of Financial Assets Transfers of Financial Assets http://nisource.com/role/TransfersOfFinancialAssets false R17.xml false Sheet 0212 - Disclosure - Goodwill Assets Goodwill Assets http://nisource.com/role/GoodwillAssets false R18.xml false Sheet 0213 - Disclosure - Income Taxes Income Taxes http://nisource.com/role/IncomeTaxes false R19.xml false Sheet 0214 - Disclosure - Pension and Other Postretirement Benefits Pension and Other Postretirement Benefits http://nisource.com/role/PensionAndOtherPostretirementBenefits false R20.xml false Sheet 0215 - Disclosure - Variable Interests and Variable Interest Entities Variable Interests and Variable Interest Entities http://nisource.com/role/VariableInterestsAndVariableInterestEntities false R21.xml false Sheet 0216 - Disclosure - Long-Term Debt Long-Term Debt http://nisource.com/role/LongTermDebt false R22.xml false Sheet 0217 - Disclosure - Short-Term Borrowings Short-Term Borrowings http://nisource.com/role/ShortTermBorrowings false R23.xml false Sheet 0218 - Disclosure - Share-Based Compensation Share-Based Compensation http://nisource.com/role/ShareBasedCompensation false R24.xml false Sheet 0219 - Disclosure - Other Commitments and Contingencies Other Commitments and Contingencies http://nisource.com/role/OtherCommitmentsAndContingencies false R25.xml false Sheet 0220 - Disclosure - Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss http://nisource.com/role/AccumulatedOtherComprehensiveLoss false R26.xml false Sheet 0221 - Disclosure - Business Segment Information Business Segment Information http://nisource.com/role/BusinessSegmentInformation false R27.xml false Sheet 0222 - Disclosure - Supplemental Cash Flow Information Supplemental Cash Flow Information http://nisource.com/role/SupplementalCashFlowInformation false R28.xml false Book All Reports All Reports false 1 9 0 0 3 195 true false January-01-2010_June-30-2010 114 SixMonthsEnded_30Jun2009 82 BalanceAsOf_31Dec2009 74 ThreeMonthsEnded_30Jun2010 33 BalanceAsOf_30Jul2010 1 BalanceAsOf_31Dec2008 1 ThreeMonthsEnded_30Jun2009 36 BalanceAsOf_30Jun2009 2 BalanceAsOf_30Jun2010 74 true true