2.2.0.25truefalse051 - Statement - Deferred Revenue (Detail)truefalseIn Millionsfalse1falsefalseUSDtruefalse{us-gaap_DeferredRevenueArrangementTypeAxis} : Deferred Revenue [Member] 9/30/2010 USD ($) $c58_AsOf30Sep2010_DeferredRevenueMemberhttp://www.sec.gov/CIK0000353944instant2010-09-30T00:00:000001-01-01T00:00:00falsefalseDeferred Revenue [Member]us-gaap_DeferredRevenueArrangementTypeAxisxbrldihttp://xbrl.org/2006/xbrldiigt_DeferredRevenueMemberus-gaap_DeferredRevenueArrangementTypeAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{us-gaap_DeferredRevenueArrangementTypeAxis} : Deferred Revenue [Member] 9/30/2009 USD ($) $c59_AsOf30Sep2009_DeferredRevenueMemberhttp://www.sec.gov/CIK0000353944instant2009-09-30T00:00:000001-01-01T00:00:00falsefalseDeferred Revenue [Member]us-gaap_DeferredRevenueArrangementTypeAxisxbrldihttp://xbrl.org/2006/xbrldiigt_DeferredRevenueMemberus-gaap_DeferredRevenueArrangementTypeAxisexplicitMemberusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false0us-gaap_AccruedLiabilitiesCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse8160000081.6falsetruefalsefalsefalse2truefalsefalse101700000101.7falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 falsefalseOther accrued liabiltites (current)3false0igt_DeferredRevenueOtherLiabilitiesNoncurrentigtfalsecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse86000008.6falsefalsefalsefalsefalse2truefalsefalse2030000020.3falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.falsefalseOther liabilities (noncurrent)4false0igt_DeferredRevenueLiabilitiesigtfalsecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse9020000090.2falsetruefalsefalsefalse2truefalsefalse122000000122.0falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNo definition available.No authoritative reference available.falsefalseTotal23Deferred Revenue (Detail) (Deferred Revenue [Member], USD $)HundredThousandsUnKnownUnKnownUnKnownfalsetrue