2.4.0.6 Html 956 838 1 false 282 0 false 32 false false R1.htm 0000 - Document - Document and Entity Information Sheet http://www.integrysgroup.com/role/DocumentAndEntityInformation Document and Entity Information false false R2.htm 0010 - Statement - CONSOLIDATED STATEMENTS OF INCOME Sheet http://www.integrysgroup.com/role/StatementOfIncome CONSOLIDATED STATEMENTS OF INCOME true false R3.htm 0020 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.integrysgroup.com/role/BalanceSheet CONSOLIDATED BALANCE SHEETS false false R4.htm 0025 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.integrysgroup.com/role/BalanceSheetParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) false false R5.htm 0030 - Statement - CONSOLIDATED STATEMENTS OF EQUITY Sheet http://www.integrysgroup.com/role/StatementOfStockholdersEquity CONSOLIDATED STATEMENTS OF EQUITY false false R6.htm 0035 - Statement - CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) Sheet http://www.integrysgroup.com/role/StatementOfStockholdersEquityParenthetical CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) false false R7.htm 0040 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.integrysgroup.com/role/CashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS false false R8.htm 1010 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES false false R9.htm 1020 - Disclosure - RISK MANAGEMENT ACTIVITIES Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivities RISK MANAGEMENT ACTIVITIES false false R10.htm 1030 - Disclosure - RESTRUCTURING EXPENSE Sheet http://www.integrysgroup.com/role/DisclosureRestructuringExpense RESTRUCTURING EXPENSE false false R11.htm 1040 - Disclosure - ACQUISITION Sheet http://www.integrysgroup.com/role/DisclosureAcquisition ACQUISITION false false R12.htm 1050 - Disclosure - DISPOSITIONS Sheet http://www.integrysgroup.com/role/DisclosureDispositions DISPOSITIONS false false R13.htm 1060 - Disclosure - PROPERTY, PLANT, AND EQUIPMENT Sheet http://www.integrysgroup.com/role/DisclosurePropertyPlantAndEquipment PROPERTY, PLANT, AND EQUIPMENT false false R14.htm 1070 - Disclosure - JOINTLY OWNED UTILITY FACILITIES Sheet http://www.integrysgroup.com/role/DisclosureJointlyOwnedUtilityFacilities JOINTLY OWNED UTILITY FACILITIES false false R15.htm 1080 - Disclosure - REGULATORY ASSETS AND LIABILITIES Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryAssetsAndLiabilities REGULATORY ASSETS AND LIABILITIES false false R16.htm 1090 - Disclosure - INVESTMENTS IN AFFILIATES, AT EQUITY METHOD Sheet http://www.integrysgroup.com/role/DisclosureInvestmentsInAffiliatesAtEquityMethod INVESTMENTS IN AFFILIATES, AT EQUITY METHOD false false R17.htm 1100 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS Sheet http://www.integrysgroup.com/role/DisclosureGoodwillAndOtherIntangibleAssets GOODWILL AND OTHER INTANGIBLE ASSETS false false R18.htm 1110 - Disclosure - LEASES Sheet http://www.integrysgroup.com/role/DisclosureLeases LEASES false false R19.htm 1120 - Disclosure - SHORT-TERM DEBT AND LINES OF CREDIT Sheet http://www.integrysgroup.com/role/DisclosureShortTermDebtAndLinesOfCredit SHORT-TERM DEBT AND LINES OF CREDIT false false R20.htm 1130 - Disclosure - LONG-TERM DEBT Sheet http://www.integrysgroup.com/role/DisclosureLongTermDebt LONG-TERM DEBT false false R21.htm 1140 - Disclosure - ASSET RETIREMENT OBLIGATIONS Sheet http://www.integrysgroup.com/role/DisclosureAssetRetirementObligations ASSET RETIREMENT OBLIGATIONS false false R22.htm 1150 - Disclosure - INCOME TAXES Sheet http://www.integrysgroup.com/role/DisclosureIncomeTaxes INCOME TAXES false false R23.htm 1160 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.integrysgroup.com/role/DisclosureCommitmentsAndContingencies COMMITMENTS AND CONTINGENCIES false false R24.htm 1170 - Disclosure - GUARANTEES Sheet http://www.integrysgroup.com/role/DisclosureGuarantees GUARANTEES false false R25.htm 1180 - Disclosure - EMPLOYEE BENEFIT PLANS Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlans EMPLOYEE BENEFIT PLANS false false R26.htm 1190 - Disclosure - PREFERRED STOCK OF SUBSIDIARY Sheet http://www.integrysgroup.com/role/DisclosurePreferredStockOfSubsidiary PREFERRED STOCK OF SUBSIDIARY false false R27.htm 1200 - Disclosure - COMMON EQUITY Sheet http://www.integrysgroup.com/role/DisclosureCommonEquity COMMON EQUITY false false R28.htm 1210 - Disclosure - STOCK-BASED COMPENSATION Sheet http://www.integrysgroup.com/role/DisclosureStockBasedCompensation STOCK-BASED COMPENSATION false false R29.htm 1220 - Disclosure - VARIABLE INTEREST ENTITIES Sheet http://www.integrysgroup.com/role/DisclosureVariableInterestEntities VARIABLE INTEREST ENTITIES false false R30.htm 1230 - Disclosure - FAIR VALUE Sheet http://www.integrysgroup.com/role/DisclosureFairValue FAIR VALUE false false R31.htm 1240 - Disclosure - ADVERTISING COSTS Sheet http://www.integrysgroup.com/role/DisclosureAdvertisingCosts ADVERTISING COSTS false false R32.htm 1250 - Disclosure - MISCELLANEOUS INCOME Sheet http://www.integrysgroup.com/role/DisclosureMiscellaneousIncome MISCELLANEOUS INCOME false false R33.htm 1260 - Disclosure - REGULATORY ENVIRONMENT Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryEnvironment REGULATORY ENVIRONMENT false false R34.htm 1270 - Disclosure - SEGMENTS OF BUSINESS Sheet http://www.integrysgroup.com/role/DisclosureSegmentsOfBusiness SEGMENTS OF BUSINESS false false R35.htm 1280 - Disclosure - QUARTERLY FINANCIAL INFORMATION (Unaudited) Sheet http://www.integrysgroup.com/role/DisclosureQuarterlyFinancialInformation QUARTERLY FINANCIAL INFORMATION (Unaudited) false false R36.htm 1290 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS Sheet http://www.integrysgroup.com/role/DisclosureCondensedParentCompanyFinancialStatements SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS false false R37.htm 1300 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS Sheet http://www.integrysgroup.com/role/DisclosureValuationAndQualifyingAccounts SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS false false R38.htm 2010 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) false false R39.htm 3010 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) false false R40.htm 3020 - Disclosure - RISK MANAGEMENT ACTIVITIES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesTables RISK MANAGEMENT ACTIVITIES (Tables) false false R41.htm 3030 - Disclosure - RESTRUCTURING EXPENSE (Tables) Sheet http://www.integrysgroup.com/role/DisclosureRestructuringExpenseTables RESTRUCTURING EXPENSE (Tables) false false R42.htm 3050 - Disclosure - DISPOSITIONS (Tables) Sheet http://www.integrysgroup.com/role/DisclosureDispositionsTables DISPOSITIONS (Tables) false false R43.htm 3060 - Disclosure - PROPERTY, PLANT, AND EQUIPMENT (Tables) Sheet http://www.integrysgroup.com/role/DisclosurePropertyPlantAndEquipmentTables PROPERTY, PLANT, AND EQUIPMENT (Tables) false false R44.htm 3070 - Disclosure - JOINTLY OWNED UTILITY FACILITIES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureJointlyOwnedUtilityFacilitiesTables JOINTLY OWNED UTILITY FACILITIES (Tables) false false R45.htm 3080 - Disclosure - REGULATORY ASSETS AND LIABILITIES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryAssetsAndLiabilitiesTables REGULATORY ASSETS AND LIABILITIES (Tables) false false R46.htm 3090 - Disclosure - INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Tables) Sheet http://www.integrysgroup.com/role/DisclosureInvestmentsInAffiliatesAtEquityMethodTables INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Tables) false false R47.htm 3100 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables) Sheet http://www.integrysgroup.com/role/DisclosureGoodwillAndOtherIntangibleAssetTables GOODWILL AND OTHER INTANGIBLE ASSETS (Tables) false false R48.htm 3110 - Disclosure - LEASES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureLeasesTables LEASES (Tables) false false R49.htm 3120 - Disclosure - SHORT-TERM DEBT AND LINES OF CREDIT (Tables) Sheet http://www.integrysgroup.com/role/DisclosureShortTermDebtAndLinesOfCreditTables SHORT-TERM DEBT AND LINES OF CREDIT (Tables) false false R50.htm 3130 - Disclosure - LONG-TERM DEBT (Tables) Sheet http://www.integrysgroup.com/role/DisclosureLongTermDebtTables LONG-TERM DEBT (Tables) false false R51.htm 3140 - Disclosure - ASSET RETIREMENT OBLIGATIONS (Tables) Sheet http://www.integrysgroup.com/role/DisclosureAssetRetirementObligationsTables ASSET RETIREMENT OBLIGATIONS (Tables) false false R52.htm 3150 - Disclosure - INCOME TAXES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureIncomeTaxesTables INCOME TAXES (Tables) false false R53.htm 3170 - Disclosure - GUARANTEES (Tables) Sheet http://www.integrysgroup.com/role/DisclosureGuaranteesTables GUARANTEES (Tables) false false R54.htm 3180 - Disclosure - EMPLOYEE BENEFIT PLANS (Tables) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansTables EMPLOYEE BENEFIT PLANS (Tables) false false R55.htm 3190 - Disclosure - PREFERRED STOCK OF SUBSIDIARY (Tables) Sheet http://www.integrysgroup.com/role/DisclosurePreferredStockOfSubsidiaryTables PREFERRED STOCK OF SUBSIDIARY (Tables) false false R56.htm 3200 - Disclosure - COMMON EQUITY (Tables) Sheet http://www.integrysgroup.com/role/DisclosureCommonEquityTables COMMON EQUITY (Tables) false false R57.htm 3210 - Disclosure - STOCK-BASED COMPENSATION (Tables) Sheet http://www.integrysgroup.com/role/DisclosureStockBasedCompensationTables STOCK-BASED COMPENSATION (Tables) false false R58.htm 3230 - Disclosure - FAIR VALUE (Tables) Sheet http://www.integrysgroup.com/role/DisclosureFairValueTables FAIR VALUE (Tables) false false R59.htm 3250 - Disclosure - MISCELLANEOUS INCOME (Tables) Sheet http://www.integrysgroup.com/role/DisclosureMiscellaneousIncomeTables MISCELLANEOUS INCOME (Tables) false false R60.htm 3270 - Disclosure - SEGMENTS OF BUSINESS (Tables) Sheet http://www.integrysgroup.com/role/DisclosureSegmentsOfBusinessTables SEGMENTS OF BUSINESS (Tables) false false R61.htm 3280 - Disclosure - QUARTERLY FINANCIAL INFORMATION (Unaudited) (Tables) Sheet http://www.integrysgroup.com/role/DisclosureQuarterlyFinancialInformationTables QUARTERLY FINANCIAL INFORMATION (Unaudited) (Tables) false false R62.htm 4010 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) false false R63.htm 4011 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) false false R64.htm 4012 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) false false R65.htm 4013 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails4 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) false false R66.htm 4014 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails5 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 5) false false R67.htm 4015 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 6) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails6 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 6) false false R68.htm 4016 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 7) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails7 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 7) false false R69.htm 4017 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 8) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails8 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 8) false false R70.htm 4018 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 9) Sheet http://www.integrysgroup.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails9 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 9) false false R71.htm 4020 - Disclosure - RISK MANAGEMENT ACTIVITIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesDetails RISK MANAGEMENT ACTIVITIES (Details) false false R72.htm 4021 - Disclosure - RISK MANAGEMENT ACTIVITIES (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesDetails2 RISK MANAGEMENT ACTIVITIES (Details 2) false false R73.htm 4022 - Disclosure - RISK MANAGEMENT ACTIVITIES (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesDetails3 RISK MANAGEMENT ACTIVITIES (Details 3) false false R74.htm 4023 - Disclosure - RISK MANAGEMENT ACTIVITIES (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesDetails4 RISK MANAGEMENT ACTIVITIES (Details 4) false false R75.htm 4024 - Disclosure - RISK MANAGEMENT ACTIVITIES (Details 5) Sheet http://www.integrysgroup.com/role/DisclosureRiskManagementActivitiesDetails5 RISK MANAGEMENT ACTIVITIES (Details 5) false false R76.htm 4030 - Disclosure - RESTRUCTURING EXPENSE (Details) Sheet http://www.integrysgroup.com/role/DisclosureRestructuringExpenseDetails RESTRUCTURING EXPENSE (Details) false false R77.htm 4040 - Disclosure - ACQUISITION (Details) Sheet http://www.integrysgroup.com/role/DisclosureAcquisitionDetails ACQUISITION (Details) false false R78.htm 4050 - Disclosure - DISPOSITIONS (Details) Sheet http://www.integrysgroup.com/role/DisclosureDispositionsDetails DISPOSITIONS (Details) false false R79.htm 4060 - Disclosure - PROPERTY, PLANT, AND EQUIPMENT (Details) Sheet http://www.integrysgroup.com/role/DisclosurePropertyPlantAndEquipmentDetails PROPERTY, PLANT, AND EQUIPMENT (Details) false false R80.htm 4070 - Disclosure - JOINTLY OWNED UTILITY FACILITIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureJointlyOwnedUtilityFacilitiesDetails JOINTLY OWNED UTILITY FACILITIES (Details) false false R81.htm 4080 - Disclosure - REGULATORY ASSETS AND LIABILITIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryAssetsAndLiabilitiesDetails REGULATORY ASSETS AND LIABILITIES (Details) false false R82.htm 4081 - Disclosure - REGULATORY ASSETS AND LIABILITIES (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryAssetsAndLiabilitiesDetails2 REGULATORY ASSETS AND LIABILITIES (Details 2) false false R83.htm 4090 - Disclosure - INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details) Sheet http://www.integrysgroup.com/role/DisclosureInvestmentsInAffiliatesAtEquityMethodDetails INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details) false false R84.htm 4091 - Disclosure - INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureInvestmentsInAffiliatesAtEquityMethodDetails2 INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details 2) false false R85.htm 4092 - Disclosure - INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureInvestmentsInAffiliatesAtEquityMethodDetails3 INVESTMENTS IN AFFILIATES, AT EQUITY METHOD (Details 3) false false R86.htm 4100 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Details) Sheet http://www.integrysgroup.com/role/DisclosureGoodwillAndOtherIntangibleAssetDetails GOODWILL AND OTHER INTANGIBLE ASSETS (Details) false false R87.htm 4101 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureGoodwillAndOtherIntangibleAssetDetails2 GOODWILL AND OTHER INTANGIBLE ASSETS (Details 2) false false R88.htm 4110 - Disclosure - LEASES (Details) Sheet http://www.integrysgroup.com/role/DisclosureLeasesDetails LEASES (Details) false false R89.htm 4120 - Disclosure - SHORT-TERM DEBT AND LINES OF CREDIT (Details) Sheet http://www.integrysgroup.com/role/DisclosureShortTermDebtAndLinesOfCreditDetails SHORT-TERM DEBT AND LINES OF CREDIT (Details) false false R90.htm 4121 - Disclosure - SHORT-TERM DEBT AND LINES OF CREDIT (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureShortTermDebtAndLinesOfCreditDetails2 SHORT-TERM DEBT AND LINES OF CREDIT (Details 2) false false R91.htm 4130 - Disclosure - LONG-TERM DEBT (Details) Sheet http://www.integrysgroup.com/role/DisclosureLongTermDebtDetails LONG-TERM DEBT (Details) false false R92.htm 4131 - Disclosure - LONG-TERM DEBT (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureLongTermDebtDetails2 LONG-TERM DEBT (Details 2) false false R93.htm 4140 - Disclosure - ASSET RETIREMENT OBLIGATIONS (Details) Sheet http://www.integrysgroup.com/role/DisclosureAssetRetirementObligationsDetails ASSET RETIREMENT OBLIGATIONS (Details) false false R94.htm 4150 - Disclosure - INCOME TAXES (Details) Sheet http://www.integrysgroup.com/role/DisclosureIncomeTaxesDetails INCOME TAXES (Details) false false R95.htm 4151 - Disclosure - INCOME TAXES (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureIncomeTaxesDetails2 INCOME TAXES (Details 2) false false R96.htm 4160 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureCommitmentsAndContingenciesDetails COMMITMENTS AND CONTINGENCIES (Details) false false R97.htm 4161 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureCommitmentsAndContingenciesDetails2 COMMITMENTS AND CONTINGENCIES (Details 2) false false R98.htm 4170 - Disclosure - GUARANTEES (Details) Sheet http://www.integrysgroup.com/role/DisclosureGuaranteesDetails GUARANTEES (Details) false false R99.htm 4180 - Disclosure - EMPLOYEE BENEFIT PLANS (Details) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansDetails EMPLOYEE BENEFIT PLANS (Details) false false R100.htm 4181 - Disclosure - EMPLOYEE BENEFIT PLANS (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansDetails2 EMPLOYEE BENEFIT PLANS (Details 2) false false R101.htm 4182 - Disclosure - EMPLOYEE BENEFIT PLANS (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansDetails3 EMPLOYEE BENEFIT PLANS (Details 3) false false R102.htm 4183 - Disclosure - EMPLOYEE BENEFIT PLANS (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansDetails4 EMPLOYEE BENEFIT PLANS (Details 4) false false R103.htm 4184 - Disclosure - EMPLOYEE BENEFIT PLANS (Details 5) Sheet http://www.integrysgroup.com/role/DisclosureEmployeeBenefitPlansDetails5 EMPLOYEE BENEFIT PLANS (Details 5) false false R104.htm 4190 - Disclosure - PREFERRED STOCK OF SUBSIDIARY (Details) Sheet http://www.integrysgroup.com/role/DisclosurePreferredStockOfSubsidiaryDetails PREFERRED STOCK OF SUBSIDIARY (Details) false false R105.htm 4200 - Disclosure - COMMON EQUITY (Details) Sheet http://www.integrysgroup.com/role/DisclosureCommonEquityDetails COMMON EQUITY (Details) false false R106.htm 4201 - Disclosure - COMMON EQUITY (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureCommonEquityDetails2 COMMON EQUITY (Details 2) false false R107.htm 4202 - Disclosure - COMMON EQUITY (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureCommonEquityDetails3 COMMON EQUITY (Details 3) false false R108.htm 4203 - Disclosure - COMMON EQUITY (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureCommonEquityDetails4 COMMON EQUITY (Details 4) false false R109.htm 4210 - Disclosure - STOCK-BASED COMPENSATION (Details) Sheet http://www.integrysgroup.com/role/DisclosureStockBasedCompensationDetails STOCK-BASED COMPENSATION (Details) false false R110.htm 4211 - Disclosure - STOCK-BASED COMPENSATION (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureStockBasedCompensationDetails2 STOCK-BASED COMPENSATION (Details 2) false false R111.htm 4212 - Disclosure - STOCK-BASED COMPENSATION (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureStockBasedCompensationDetails3 STOCK-BASED COMPENSATION (Details 3) false false R112.htm 4220 - Disclosure - VARIABLE INTEREST ENTITIES (Details) Sheet http://www.integrysgroup.com/role/DisclosureVariableInterestEntitiesDetails VARIABLE INTEREST ENTITIES (Details) false false R113.htm 4230 - Disclosure - FAIR VALUE (Details) Sheet http://www.integrysgroup.com/role/DisclosureFairValueDetails FAIR VALUE (Details) false false R114.htm 4231 - Disclosure - FAIR VALUE (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureFairValueDetails2 FAIR VALUE (Details 2) false false R115.htm 4232 - Disclosure - FAIR VALUE (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureFairValueDetails3 FAIR VALUE (Details 3) false false R116.htm 4233 - Disclosure - FAIR VALUE (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureFairValueDetails4 FAIR VALUE (Details 4) false false R117.htm 4240 - Disclosure - ADVERTISING COSTS (Details) Sheet http://www.integrysgroup.com/role/DisclosureAdvertisingCostsDetails ADVERTISING COSTS (Details) false false R118.htm 4250 - Disclosure - MISCELLANEOUS INCOME (Details) Sheet http://www.integrysgroup.com/role/DisclosureMiscellaneousIncomeDetails MISCELLANEOUS INCOME (Details) false false R119.htm 4260 - Disclosure - REGULATORY ENVIRONMENT (Details) Sheet http://www.integrysgroup.com/role/DisclosureRegulatoryEnvironmentDetails REGULATORY ENVIRONMENT (Details) false false R120.htm 4270 - Disclosure - SEGMENTS OF BUSINESS (Details) Sheet http://www.integrysgroup.com/role/DisclosureSegmentsOfBusinessDetails SEGMENTS OF BUSINESS (Details) false false R121.htm 4271 - Disclosure - SEGMENTS OF BUSINESS (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureSegmentsOfBusinessDetails2 SEGMENTS OF BUSINESS (Details 2) false false R122.htm 4280 - Disclosure - QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) Sheet http://www.integrysgroup.com/role/DisclosureQuarterlyFinancialInformationDetails QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) false false R123.htm 4290 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details) false false R124.htm 4291 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 2) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails2 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 2) false false R125.htm 4292 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 3) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails3 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 3) false false R126.htm 4293 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 4) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails4 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 4) false false R127.htm 4294 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 5) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails5 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 5) false false R128.htm 4295 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 6) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails6 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 6) false false R129.htm 4296 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 7) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails7 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 7) false false R130.htm 4297 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 8) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails8 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 8) false false R131.htm 4298 - Disclosure - SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 9) Sheet http://www.integrysgroup.com/role/DisclosureScheduleICondensedParentCompanyFinancialStatementsDetails9 SCHEDULE I - CONDENSED PARENT COMPANY FINANCIAL STATEMENTS (Details 9) false false R132.htm 4300 - Disclosure - SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) Sheet http://www.integrysgroup.com/role/DisclosureDisclosureScheduleIICondensedParentCompanyFinancialStatementsDetailsValuationAndQualifyingAccountsDetails SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) false false All Reports Book All Reports Element teg_PropertyPlantAndEquipmentImpairmentAnalysisDiscountRate had a mix of decimals attribute values: 2 3. Element us-gaap_AssetRetirementObligation had a mix of decimals attribute values: -5 0. Element us-gaap_AssetRetirementObligationAccretionExpense had a mix of decimals attribute values: -5 0. Element us-gaap_AssetRetirementObligationCashPaidToSettle had a mix of decimals attribute values: -5 0. Element us-gaap_AssetRetirementObligationLiabilitiesSettled had a mix of decimals attribute values: -5 0. Element us-gaap_AssetRetirementObligationRevisionOfEstimate had a mix of decimals attribute values: -5 0. Element us-gaap_EquityMethodInvestmentOwnershipPercentage had a mix of decimals attribute values: 2 4. Element us-gaap_NonmonetaryNotionalAmountOfPriceRiskDerivativeInstrumentsNotDesignatedAsHedgingInstruments had a mix of decimals attribute values: -5 1. 'Monetary' elements on report '4150 - Disclosure - INCOME TAXES (Details)' had a mix of different decimal attribute values. Process Flow-Through: 0010 - Statement - CONSOLIDATED STATEMENTS OF INCOME Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2011' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2011' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2010' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2010' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2010' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2010' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2009' Process Flow-Through: 0020 - Statement - CONSOLIDATED BALANCE SHEETS Process Flow-Through: Removing column 'Dec. 31, 2009' Process Flow-Through: Removing column 'Dec. 31, 2008' Process Flow-Through: 0025 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Process Flow-Through: Removing column 'Dec. 31, 2009' Process Flow-Through: Removing column 'Dec. 31, 2008' Process Flow-Through: 0035 - Statement - CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) Process Flow-Through: 0040 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS teg-20111231.xml teg-20111231.xsd teg-20111231_cal.xml teg-20111231_def.xml teg-20111231_lab.xml teg-20111231_pre.xml true true