2.2.0.25falsefalse093 - Statement - Financial Assets (Liabilities) Not Carried at 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$2true0igt_FinancialAssetsLiabilitiesNotCarriedAtFairValueAbstractigtfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseFinancial Assets (Liabilities) Not Carried at Fair Value [Abstract]3false0us-gaap_HeldToMaturitySecuritiesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse425900000425.9falsetruefalsefalsefalse2truefalsefalse464100000464.1falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity; such investments are measured at amortized cost (carrying value). The held-to-maturity category is for those securities that the Entity has the positive intent and ability to hold until maturity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 4, 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 17 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 7, 8, 9, 10, 11 falsefalseJackpot Investments Carry Amount4false0us-gaap_HeldToMaturitySecuritiesFairValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse495200000495.2falsefalsefalsefalsefalse2truefalsefalse518000000518.0falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 137 falsefalseJackpot Investments Fair Value5false0igt_JackpotInvestmentsFVigtfalsenadurationGains on held to maturity securities.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse7310000073.1falsefalsefalsefalsefalse2truefalsefalse5410000054.1falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryGains on held to maturity securities.No authoritative reference available.falsefalseJackpot Investments Unrealized Gain6false0igt_JackpotInvestmentsLossFVigtfalsenadurationHeld to Maturity securities, losses.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse38000003.8falsefalsefalsefalsefalse2truefalsefalse2000000.2falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryHeld to Maturity securities, losses.No authoritative reference available.truefalseJackpot Investments Unrealized Loss7false0igt_NotesAndContractsReceivableigtfalsedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse356000000356.0falsefalsefalsefalsefalse2truefalsefalse404200000404.2falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.truefalseNotes Contracts Receivable Carry Amount8false0us-gaap_NotesReceivableFairValueDisclosureus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse356800000356.8falsefalsefalsefalsefalse2truefalsefalse413800000413.8falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. An amount representing an agreement for an unconditional promise by the maker to pay the Company (holder) a definite sum of money at a future date(s).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph b -Article 5 falsefalseNotes Contracts Receivable Fair Value9false0igt_NotesContractsReceivableGainFVigtfalsenadurationNotes Receivable Unrealized Gain, Fair Value.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse8000000.8falsefalsefalsefalsefalse2truefalsefalse96000009.6falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNotes Receivable Unrealized Gain, Fair Value.No authoritative reference available.falsefalseNotes Contracts Receivable Unrealized Gain10false0igt_JackpotLiabilitiesDebtInstrumentCarryingAmountigtfalsecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse-570900000-570.9falsefalsefalsefalsefalse2truefalsefalse-588100000-588.1falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.falsefalseJackpot Liabilities Carry Amount11false0igt_OtherLongTermDebtFairValueDisclosureigtfalsedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-567500000-567.5falsefalsefalsefalsefalse2truefalsefalse-595500000-595.5falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.falsefalseJackpot Liabilities Fair Value12false0igt_JackpotLiabilitiesGainFVigtfalsenadurationOther Long Term Debt Unrealized Gain, Fair Valuefalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse34000003.4falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryOther Long Term Debt Unrealized Gain, Fair ValueNo authoritative reference available.truefalseJackpot Liabilities Unrealized Gain13false0igt_JackpotLiabilitiesLossFVigtfalsenadurationOther Long Term Debt Unrealized Loss, Fair Valuefalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse74000007.4falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryOther Long Term Debt Unrealized Loss, Fair ValueNo authoritative reference available.truefalseJackpot Liabilities Unrealized Loss14false0us-gaap_DebtInstrumentCarryingAmountus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse-1622200000-1622.2falsefalsefalsefalsefalse2truefalsefalse-2004900000-2004.9falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number APB14-1 -Paragraph 31 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 falsefalseDebt Carry Amount15false0igt_LongTermDebtFairValueigtfalsedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse-1933200000-1933.2falsefalsefalsefalsefalse2truefalsefalse-2435000000-2435.0falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.falsefalseDebt Fair Value16false0igt_CreditFacilitiesIndebtednessigtfalsenadurationThis item represents, as of the balance sheet date, the gross losses in accumulated other comprehensive income, a separate...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse311000000311.0falsetruefalsefalsefalse2truefalsefalse430100000430.1falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis item represents, as of the balance sheet date, the gross losses in accumulated other comprehensive income, a separate component of shareholders' equity, for any derivatives that hedged the forecasted acquisition of held-to-maturity securities.No authoritative reference available.falsefalseDebt Unrealized Loss215Financial Assets (Liabilities) Not Carried at Fair Value (Detail) (USD $)HundredThousandsUnKnownUnKnownUnKnownfalsetrue