2.2.0.25 true Sheet 00 - Document - Document and Entity Information Document and Entity Information http://itc-holdings.com/role/DocumentAndEntityInformation false R1.xml false Sheet 0110 - Statement - Consolidated Statements of Financial Position Consolidated Statements of Financial Position http://itc-holdings.com/role/StatementsOfFinancialPosition false R2.xml false Sheet 0111 - Statement - Consolidated Statements of Financial Position (Parenthetical) Consolidated Statements of Financial Position (Parenthetical) http://itc-holdings.com/role/StatementsOfFinancialPositionParenthetical false R3.xml false Sheet 0120 - Statement - Consolidated Statements of Operations Consolidated Statements of Operations http://itc-holdings.com/role/StatementsOfOperations false R4.xml false Sheet 0130 - Statement - Consolidated Statements of Changes in Stockholders' Equity and Comprehensive Income Consolidated Statements of Changes in Stockholders' Equity and Comprehensive Income http://itc-holdings.com/role/StatementsOfChangesInStockholdersEquityAndComprehensiveIncome false R5.xml false Sheet 0131 - Statement - Consolidated Statements of Changes in Stockholders' Equity and Comprehensive Income (Parenthetical) Consolidated Statements of Changes in Stockholders' Equity and Comprehensive Income (Parenthetical) http://itc-holdings.com/role/StatementsOfChangesInStockholdersEquityAndComprehensiveIncomeParenthetical false R6.xml false Sheet 0140 - Statement - Consolidated Statements of Cash Flows Consolidated Statements of Cash Flows http://itc-holdings.com/role/StatementsOfCashFlows false R7.xml false Sheet 0201 - Disclosure - General General http://itc-holdings.com/role/General false R8.xml false Sheet 0202 - Disclosure - Significant Accounting Policies Significant Accounting Policies http://itc-holdings.com/role/SignificantAccountingPolicies false R9.xml false Sheet 0203 - Disclosure - Recent Accounting Pronouncements Recent Accounting Pronouncements http://itc-holdings.com/role/RecentAccountingPronouncements false R10.xml false Sheet 0204 - Disclosure - Regulatory Matters Regulatory Matters http://itc-holdings.com/role/RegulatoryMatters false R11.xml false Sheet 0205 - Disclosure - Regulatory Assets and Liabilities Regulatory Assets and Liabilities http://itc-holdings.com/role/RegulatoryAssetsAndLiabilities false R12.xml false Sheet 0206 - Disclosure - Goodwill and Intangible Assets Goodwill and Intangible Assets http://itc-holdings.com/role/GoodwillAndIntangibleAssets false R13.xml false Sheet 0207 - Disclosure - Property, Plant and Equipment Property, Plant and Equipment http://itc-holdings.com/role/PropertyPlantAndEquipment false R14.xml false Sheet 0208 - Disclosure - Long-Term Debt Long-Term Debt http://itc-holdings.com/role/LongTermDebt false R15.xml false Sheet 0209 - Disclosure - Earnings Per Share Earnings Per Share http://itc-holdings.com/role/EarningsPerShare false R16.xml false Sheet 0210 - Disclosure - Income Taxes Income Taxes http://itc-holdings.com/role/IncomeTaxes false R17.xml false Sheet 0211 - Disclosure - Retirement Benefits and Assets Held in Trust Retirement Benefits and Assets Held in Trust http://itc-holdings.com/role/RetirementBenefitsAndAssetsHeldInTrust false R18.xml false Sheet 0212 - Disclosure - Fair Value Measurements Fair Value Measurements http://itc-holdings.com/role/FairValueMeasurements false R19.xml false Sheet 0213 - Disclosure - Stockholders' Equity Stockholders' Equity http://itc-holdings.com/role/StockholdersEquity false R20.xml false Sheet 0214 - Disclosure - Share-Based Compensation Share-Based Compensation http://itc-holdings.com/role/ShareBasedCompensation false R21.xml false Sheet 0215 - Disclosure - Jointly Owned Utility Plant/Coordinated Services Jointly Owned Utility Plant/Coordinated Services http://itc-holdings.com/role/JointlyOwnedUtilityPlantCoordinatedServices false R22.xml false Sheet 0216 - Disclosure - Commitments and Contingencies Commitments and Contingencies http://itc-holdings.com/role/CommitmentsAndContingencies false R23.xml false Sheet 0217 - Disclosure - Segment Information Segment Information http://itc-holdings.com/role/SegmentInformation false R24.xml false Sheet 0218 - Disclosure - Supplementary Quarterly Financial Information (Unaudited) Supplementary Quarterly Financial Information (Unaudited) http://itc-holdings.com/role/SupplementaryQuarterlyFinancialInformation false R25.xml false Sheet 0301 - Schedule - Condensed Financial Information of Registrant Condensed Financial Information of Registrant http://itc-holdings.com/role/FinancialInformationOfRegistrant false R26.xml false Book All Reports All Reports false 1 33 4 0 3 153 false false TwelveMonthsEnded_31Dec2008 61 Jan-01-2010_Dec-31-2010 92 BalanceAsOf_31Dec2007 2 BalanceAsOf_31Dec2010_Common_Stock_Member 2 TwelveMonthsEnded_31Dec2009_Comprehensive_Income_Member 12 TwelveMonthsEnded_31Dec2008_Retained_Earnings_Member 15 TwelveMonthsEnded_31Dec2010_Comprehensive_Income_Member 14 BalanceAsOf_31Dec2010 43 TwelveMonthsEnded_31Dec2009_Retained_Earnings_Member 11 BalanceAsOf_31Dec2008_Retained_Earnings_Member 1 BalanceAsOf_31Dec2008 2 BalanceAsOf_31Dec2009_Accumulated_Other_Comprehensive_Income_Member 1 TwelveMonthsEnded_31Dec2009_Common_Stock_Member 16 BalanceAsOf_31Dec2007_Accumulated_Other_Comprehensive_Income_Member 1 BalanceAsOf_31Dec2007_Retained_Earnings_Member 1 BalanceAsOf_31Dec2010_Accumulated_Other_Comprehensive_Income_Member 1 TwelveMonthsEnded_31Dec2008_Accumulated_Other_Comprehensive_Income_Member 13 BalanceAsOf_31Dec2009_Common_Stock_Member 2 TwelveMonthsEnded_31Dec2008_Common_Stock_Member 17 TwelveMonthsEnded_31Dec2009_Accumulated_Other_Comprehensive_Income_Member 11 TwelveMonthsEnded_31Dec2010_Retained_Earnings_Member 12 BalanceAsOf_31Dec2009 43 BalanceAsOf_31Dec2009_Retained_Earnings_Member 1 BalanceAsOf_31Dec2008_Common_Stock_Member 2 TwelveMonthsEnded_31Dec2009 60 TwelveMonthsEnded_31Dec2010_Accumulated_Other_Comprehensive_Income_Member 13 TwelveMonthsEnded_31Dec2010_Common_Stock_Member 17 BalanceAsOf_31Dec2010_Retained_Earnings_Member 1 BalanceAsOf_31Dec2007_Common_Stock_Member 2 BalanceAsOf_18Feb2011 1 TwelveMonthsEnded_31Dec2008_Comprehensive_Income_Member 14 BalanceAsOf_30Jun2010 1 BalanceAsOf_31Dec2008_Accumulated_Other_Comprehensive_Income_Member 1 true true