2.2.0.25falsefalse090 - Statement - Income Statement Location and Fair Value (Detail)truefalseIn Millionsfalse1falsefalseUSDfalsefalse10/1/2009 - 9/30/2010 USD ($) / shares USD ($) $c0_From1Oct2009To30Sep2010http://www.sec.gov/CIK0000353944duration2009-10-01T00:00:002010-09-30T00:00:00ratioStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDfalsefalse10/1/2008 - 9/30/2009 USD ($) USD ($) / shares $c1_From1Oct2008To30Sep2009http://www.sec.gov/CIK0000353944duration2008-10-01T00:00:002009-09-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170usdPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0ratioStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$3true0igt_NonDesignatedHedgesAbstract0igtfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseNon-designated Hedges4false0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-1500000-1.5falsetruefalsefalsefalse2truefalsefalse-900000-0.9falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of net gains and losses recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph b falsefalseForeign currency contracts: Other income (expense)5true0igt_DesignatedHedgesAbstract0igtfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseDesignated Hedges6false0igt_ForeignCurrencyContractsOtherIncomeexpenseigtfalsenadurationThe amount of net gains and losses recognized in income during the period on foreign currency contracts' derivative...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse2000000.2falsefalsefalsefalsefalse2truefalsefalse3000000.3falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of net gains and losses recognized in income during the period on foreign currency contracts' derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.No authoritative reference available.falsefalseForeign currency contracts: Other income (expense)7false0us-gaap_GainLossOnFairValueHedgeIneffectivenessNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse4000000.4falsefalsefalsefalsefalse2truefalsefalse-300000-0.3falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet gain (loss) recognized in earnings during the reporting period representing the amount of the fair value of the hedges' ineffectiveness.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 45 -Subparagraph a(1) falsefalseInterest rate swap - ineffectiveness: Other income (expense)8false0us-gaap_GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse1240000012.4falsetruefalsefalsefalse2truefalsefalse29000002.9falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. 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