2.2.0.25truefalse41510 - Disclosure - Retirement Plans (Details 10)truefalseIn Thousands, unless otherwise specifiedfalse1falsefalseUSDfalsefalse12/31/2010 USD ($) USD ($) / shares $AS_OF_Dec31_2010http://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170EPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2falsefalseUSDfalsefalse12/31/2009 USD ($) USD ($) / shares $AS_OF_Dec31_2009http://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170EPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$4falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$6falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$7falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$8falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$9falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$10falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Large-Cap U S Companies [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_LargeCapUSCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseLarge-Cap U S Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_LargeCapUSCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli011falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Large-Cap U S Companies [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_LargeCapUSCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseLarge-Cap U S Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_LargeCapUSCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli012falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : International Growth Companies [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_InternationalGrowthCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseInternational Growth Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_InternationalGrowthCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli013falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : International Growth Companies [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_InternationalGrowthCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseInternational Growth Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_InternationalGrowthCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli014falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Fixed Income Bonds [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_FixedIncomeBondsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseFixed Income Bonds [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_FixedIncomeBondsMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli015falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Fixed Income Bonds [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_FixedIncomeBondsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseFixed Income Bonds [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_FixedIncomeBondsMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli016falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Common Stocks [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquitySecuritiesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCommon Stocks [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquitySecuritiesMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$17falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Common Stocks [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquitySecuritiesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCommon Stocks [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquitySecuritiesMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$18falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Common Stocks [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquitySecuritiesMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCommon Stocks [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquitySecuritiesMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$19falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Common Stocks [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquitySecuritiesMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCommon Stocks [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquitySecuritiesMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$20falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$21falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$22falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$23falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$24falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Hedge Funds [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_HedgeFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseHedge Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_HedgeFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$25falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Hedge Funds [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_HedgeFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseHedge Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_HedgeFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$26falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Hedge Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_HedgeFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseHedge Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_HedgeFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$27falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Hedge Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_HedgeFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseHedge Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_HedgeFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$28falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Hedge Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_HedgeFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseHedge Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_HedgeFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$29falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$30falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$31falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$32falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$33falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$34falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$35falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$36falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$37falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$38falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$39falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$40falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$41falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$42falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Large-Cap U S Companies [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_LargeCapUSCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseLarge-Cap U S Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_LargeCapUSCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli043falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Large-Cap U S Companies [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_LargeCapUSCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseLarge-Cap U S Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_LargeCapUSCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli044falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : International Growth Companies [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_InternationalGrowthCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseInternational Growth Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_InternationalGrowthCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli045falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : International Growth Companies [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_InternationalGrowthCompaniesMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseInternational Growth Companies [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_InternationalGrowthCompaniesMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli046falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Fixed Income Bonds [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_FixedIncomeBondsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseFixed Income Bonds [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_FixedIncomeBondsMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli047falsefalsetruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {wat_PlanAssetCategoriesByComponentAxis} : Fixed Income Bonds [Member] 12/31/2009 AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_wat_PlanAssetCategoriesByComponentAxis_FixedIncomeBondsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseFixed Income Bonds [Member]wat_PlanAssetCategoriesByComponentAxisxbrldihttp://xbrl.org/2006/xbrldiwat_FixedIncomeBondsMemberwat_PlanAssetCategoriesByComponentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli048falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$49falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$50falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$51falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$52falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$53falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$54falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$55falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : U.S. Retiree Healthcare Plan {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseU.S. Retiree Healthcare Planus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_UnitedStatesPostretirementBenefitPlansOfUSEntityDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$56falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$57falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$58falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$59falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$60falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$61falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$62falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Mutual Funds [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_EquityFundsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseMutual Funds [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_EquityFundsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$63falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$64falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$65falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$66falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Cash Equivalents [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_CashAndCashEquivalentsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseCash Equivalents [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_CashAndCashEquivalentsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$67falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Bank and Insurance Investment Contracts [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_BankAndInsuranceInvestmentContractsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseBank and Insurance Investment Contracts [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldiwat_BankAndInsuranceInvestmentContractsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$68falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Bank and Insurance Investment Contracts [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_BankAndInsuranceInvestmentContractsMember_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseBank and Insurance Investment Contracts [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldiwat_BankAndInsuranceInvestmentContractsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$69falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Bank and Insurance Investment Contracts [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_BankAndInsuranceInvestmentContractsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseBank and Insurance Investment Contracts [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldiwat_BankAndInsuranceInvestmentContractsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$70falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Bank and Insurance Investment Contracts [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_BankAndInsuranceInvestmentContractsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseBank and Insurance Investment Contracts [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldiwat_BankAndInsuranceInvestmentContractsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$71falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis} : Bank and Insurance Investment Contracts [Member] {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_BankAndInsuranceInvestmentContractsMember_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseBank and Insurance Investment Contracts [Member]us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisxbrldihttp://xbrl.org/2006/xbrldiwat_BankAndInsuranceInvestmentContractsMemberus-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$72falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$73falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$74falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$75falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis} : Non-U.S. Pension Plans {us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Member_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_ForeignPensionPlansDefinedBenefitMemberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseNon-U.S. Pension Plansus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ForeignPensionPlansDefinedBenefitMemberus-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxisexplicitMemberfalsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$76falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Memberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$77falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Quoted Prices in Active Market for Identical Assets (Level 1) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel1Memberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseQuoted Prices in Active Market for Identical Assets (Level 1) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel1Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$78falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Memberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$79falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Other Observable Inputs (Level 2) 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel2Memberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseSignificant Other Observable Inputs (Level 2)us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel2Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$80falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Memberhttp://www.sec.gov/CIK0001000697instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$81falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Memberhttp://www.sec.gov/CIK0001000697instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$82falsefalseUSDtruefalse{us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis} : Significant Unobservable Inputs (Level 3) [Member] 12/31/2008 USD ($) $AS_OF_Dec31_2008_us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxis_FairValueInputsLevel3Memberhttp://www.sec.gov/CIK0001000697instant2008-12-31T00:00:000001-01-01T00:00:00falsefalseSignificant Unobservable Inputs (Level 3) [Member]us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueInputsLevel3Memberus-gaap_DefinedBenefitPlanFairValueOfPlanAssetsByMeasurementAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2true0us-gaap_DefinedBenefitPlanDisclosureLineItemsus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalse8falsefalsefalse00falsefalsefalsetruefalse9falsefalsefalse00falsefalsefalsetruefalse10falsefalsefalse00falsefalsefalsetruefalse11falsefalsefalse00falsefalsefalsetruefalse12falsefalsefalse00falsefalsefalsetruefalse13falsefalsefalse00falsefalsefalsetruefalse14falsefalsefalse00falsefalsefalsetruefalse15falsefalsefalse00falsefalsefalsetruefalse16falsefalsefalse00falsefalsefalsetruefalse17falsefalsefalse00falsefalsefalsetruefalse18falsefalsefalse00falsefalsefalsetruefalse19falsefalsefalse00falsefalsefalsetruefalse20falsefalsefalse00falsefalsefalsetruefalse21falsefalsefalse00falsefalsefalsetruefalse22falsefalsefalse00falsefalsefalsetruefalse23falsefalsefalse00falsefalsefalsetruefalse24falsefalsefalse00falsefalsefalsetruefalse25falsefalsefalse00falsefalsefalsetruefalse26falsefalsefalse00falsefalsefalsetruefalse27falsefalsefalse00falsefalsefalsetruefalse28falsefalsefalse00falsefalsefalsetruefalse29falsefalsefalse00falsefalsefalsetruefalse30falsefalsefalse00falsefalsefalsetruefalse31falsefalsefalse00falsefalsefalsetruefalse32falsefalsefalse00falsefalsefalsetruefalse33falsefalsefalse00falsefalsefalsetruefalse34falsefalsefalse00falsefalsefalsetruefalse35falsefalsefalse00falsefalsefalsetruefalse36falsefalsefalse00falsefalsefalsetruefalse37falsefalsefalse00falsefalsefalsetruefalse38falsefalsefalse00falsefalsefalsetruefalse39falsefalsefalse00falsefalsefalsetruefalse40falsefalsefalse00falsefalsefalsetruefalse41falsefalsefalse00falsefalsefalsetruefalse42falsefalsefalse00falsefalsefalsetruefalse43falsefalsefalse00falsefalsefalsetruefalse44falsefalsefalse00falsefalsefalsetruefalse45falsefalsefalse00falsefalsefalsetruefalse46falsefalsefalse00falsefalsefalsetruefalse47falsefalsefalse00falsefalsefalsetruefalse48falsefalsefalse00falsefalsefalsetruefalse49falsefalsefalse00falsefalsefalsetruefalse50falsefalsefalse00falsefalsefalsetruefalse51falsefalsefalse00falsefalsefalsetruefalse52falsefalsefalse00falsefalsefalsetruefalse53falsefalsefalse00falsefalsefalsetruefalse54falsefalsefalse00falsefalsefalsetruefalse55falsefalsefalse00falsefalsefalsetruefalse56falsefalsefalse00falsefalsefalsetruefalse57falsefalsefalse00falsefalsefalsetruefalse58falsefalsefalse00falsefalsefalsetruefalse59falsefalsefalse00falsefalsefalsetruefalse60falsefalsefalse00falsefalsefalsetruefalse61falsefalsefalse00falsefalsefalsetruefalse62falsefalsefalse00falsefalsefalsetruefalse63falsefalsefalse00falsefalsefalsetruefalse64falsefalsefalse00falsefalsefalsetruefalse65falsefalsefalse00falsefalsefalsetruefalse66falsefalsefalse00falsefalsefalsetruefalse67falsefalsefalse00falsefalsefalsetruefalse68falsefalsefalse00falsefalsefalsetruefalse69falsefalsefalse00falsefalsefalsetruefalse70falsefalsefalse00falsefalsefalsetruefalse71falsefalsefalse00falsefalsefalsetruefalse72falsefalsefalse00falsefalsefalsetruefalse73falsefalsefalse00falsefalsefalsetruefalse74falsefalsefalse00falsefalsefalsetruefalse75falsefalsefalse00falsefalsefalsetruefalse76falsefalsefalse00falsefalsefalsetruefalse77falsefalsefalse00falsefalsefalsetruefalse78falsefalsefalse00falsefalsefalsetruefalse79falsefalsefalse00falsefalsefalsetruefalse80falsefalsefalse00falsefalsefalsetruefalse81falsefalsefalse00falsefalsefalsetruefalse82falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringLine items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.falsefalseDefined Benefit Plan Disclosure [Line Items]3false0us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse108929000108929falsetruefalsefalsefalse2truefalsefalse9667400096674falsetruefalsefalsefalse3truefalsefalse9318700093187falsetruefalsetruefalse4truefalsefalse8252300082523falsetruefalsetruefalse5truefalsefalse5845600058456falsetruefalsetruefalse6truefalsefalse8325700083257[1]falsetruefalsetruefalse7truefalsefalse7163600071636[1]falsetruefalsetruefalse8truefalsefalse8325700083257[1]falsetruefalsetruefalse9truefalsefalse7163600071636[1]falsetruefalsetruefalse10falsefalsefalse00falsefalsefalsetruefalse11falsefalsefalse00falsefalsefalsetruefalse12falsefalsefalse00falsefalsefalsetruefalse13falsefalsefalse00falsefalsefalsetruefalse14falsefalsefalse00falsefalsefalsetruefalse15falsefalsefalse00falsefalsefalsetruefalse16truefalsefalse45600004560[2]falsetruefalsetruefalse17truefalsefalse36600003660[2]falsetruefalsetruefalse18truefalsefalse45600004560[2]falsetruefalsetruefalse19truefalsefalse36600003660[2]falsetruefalsetruefalse20truefalsefalse488000488[3]falsetruefalsetruefalse21truefalsefalse18100001810[3]falsetruefalsetruefalse22truefalsefalse488000488[3]falsetruefalsetruefalse23truefalsefalse18100001810[3]falsetruefalsetruefalse24truefalsefalse48820004882[4]falsetruefalsetruefalse25truefalsefalse54170005417[4]falsetruefalsetruefalse26truefalsefalse48820004882[4]falsetruefalsetruefalse27truefalsefalse54170005417[4]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[5]falsetruefalsetruefalse39truefalsefalse26290002629[6]falsetruefalsetruefalse40truefalsefalse28740002874[5]falsetruefalsetruefalse41truefalsefalse26290002629[6]falsetruefalsetruefalse42falsefalsefalse00falsefalsefalsetruefalse43falsefalsefalse00falsefalsefalsetruefalse44falsefalsefalse00falsefalsefalsetruefalse45falsefalsefalse00falsefalsefalsetruefalse46falsefalsefalse00falsefalsefalsetruefalse47falsefalsefalse00falsefalsefalsetruefalse48truefalsefalse934000934[3]falsetruefalsetruefalse49truefalsefalse455000455[3]falsetruefalsetruefalse50truefalsefalse934000934[3]falsetruefalsetruefalse51truefalsefalse455000455[3]falsetruefalsetruefalse52truefalsefalse28740002874falsetruefalsetruefalse53truefalsefalse26290002629falsetruefalsetruefalse54truefalsefalse934000934falsetruefalsetruefalse55truefalsefalse455000455falsetruefalsetruefalse56truefalsefalse1193400011934falsetruefalsetruefalse57truefalsefalse1106700011067falsetruefalsetruefalse58truefalsefalse1006900010069falsetruefalsetruefalse59truefalsefalse00[7]falsetruefalsetruefalse60truefalsefalse175000175[7]falsetruefalsetruefalse61truefalsefalse00[7]falsetruefalsetruefalse62truefalsefalse175000175[7]falsetruefalsetruefalse63truefalsefalse60210006021[3]falsetruefalsetruefalse64truefalsefalse58900005890[3]falsetruefalsetruefalse65truefalsefalse60210006021[3]falsetruefalsetruefalse66truefalsefalse58900005890[3]falsetruefalsetruefalse67truefalsefalse59130005913[8]falsetruefalsetruefalse68truefalsefalse50020005002[8]falsetruefalsetruefalse69truefalsefalse59130005913[8]falsetruefalsetruefalse70truefalsefalse50020005002[8]falsetruefalsetruefalse71truefalsefalse46070004607falsetruefalsetruefalse72truefalsefalse60210006021falsetruefalsetruefalse73truefalsefalse60650006065falsetruefalsetruefalse74truefalsefalse59130005913falsetruefalsetruefalse75truefalsefalse50020005002falsetruefalsetruefalse76truefalsefalse9671200096712falsetruefalsetruefalse77truefalsefalse8399000083990falsetruefalsetruefalse78truefalsefalse14220001422falsetruefalsetruefalse79truefalsefalse22650002265falsetruefalsetruefalse80truefalsefalse1079500010795falsetruefalsetruefalse81truefalsefalse1041900010419falsetruefalsetruefalse82truefalsefalse84660008466falsetruefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAssets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those nonbenefit obligations may be considered as reductions of plan assets.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 49 falsefalseFair value of defined benefit plan assets4false0wat_ComponentsOfPlanAssetCategorieswatfalsenainstantThe percentage of the fair value of investment to the fair value of total plan asset category held as of the measurement...falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsefalsefalse2falsetruefalse00falsefalsefalsefalsefalse3falsetruefalse00falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalse6falsetruefalse00falsefalsefalsetruefalse7falsetruefalse00falsefalsefalsetruefalse8falsetruefalse00falsefalsefalsetruefalse9falsetruefalse00falsefalsefalsetruefalse10truetruefalse0.380.38falsefalsefalsetruefalse11truetruefalse0.380.38falsefalsefalsetruefalse12truetruefalse0.270.27falsefalsefalsetruefalse13truetruefalse0.270.27falsefalsefalsetruefalse14truetruefalse0.350.35falsefalsefalsetruefalse15truetruefalse0.350.35falsefalsefalsetruefalse16falsetruefalse00falsefalsefalsetruefalse17falsetruefalse00falsefalsefalsetruefalse18falsetruefalse00falsefalsefalsetruefalse19falsetruefalse00falsefalsefalsetruefalse20falsetruefalse00falsefalsefalsetruefalse21falsetruefalse00falsefalsefalsetruefalse22falsetruefalse00falsefalsefalsetruefalse23falsetruefalse00falsefalsefalsetruefalse24falsetruefalse00falsefalsefalsetruefalse25falsetruefalse00falsefalsefalsetruefalse26falsetruefalse00falsefalsefalsetruefalse27falsetruefalse00falsefalsefalsetruefalse28falsetruefalse00falsefalsefalsetruefalse29falsetruefalse00falsefalsefalsetruefalse30falsetruefalse00falsefalsefalsetruefalse31falsetruefalse00falsefalsefalsetruefalse32falsetruefalse00falsefalsefalsetruefalse33falsetruefalse00falsefalsefalsetruefalse34falsetruefalse00falsefalsefalsetruefalse35falsetruefalse00falsefalsefalsetruefalse36falsetruefalse00falsefalsefalsetruefalse37falsetruefalse00falsefalsefalsetruefalse38falsetruefalse00falsefalsefalsetruefalse39falsetruefalse00falsefalsefalsetruefalse40falsetruefalse00falsefalsefalsetruefalse41falsetruefalse00falsefalsefalsetruefalse42truetruefalse0.720.72falsefalsefalsetruefalse43truetruefalse0.610.61falsefalsefalsetruefalse44truetruefalse0.090.09falsefalsefalsetruefalse45truetruefalse0.120.12falsefalsefalsetruefalse46truetruefalse0.190.19falsefalsefalsetruefalse47truetruefalse0.270.27falsefalsefalsetruefalse48falsetruefalse00falsefalsefalsetruefalse49falsetruefalse00falsefalsefalsetruefalse50falsetruefalse00falsefalsefalsetruefalse51falsetruefalse00falsefalsefalsetruefalse52falsetruefalse00falsefalsefalsetruefalse53falsetruefalse00falsefalsefalsetruefalse54falsetruefalse00falsefalsefalsetruefalse55falsetruefalse00falsefalsefalsetruefalse56falsetruefalse00falsefalsefalsetruefalse57falsetruefalse00falsefalsefalsetruefalse58falsetruefalse00falsefalsefalsetruefalse59falsetruefalse00falsefalsefalsetruefalse60falsetruefalse00falsefalsefalsetruefalse61falsetruefalse00falsefalsefalsetruefalse62falsetruefalse00falsefalsefalsetruefalse63falsetruefalse00falsefalsefalsetruefalse64falsetruefalse00falsefalsefalsetruefalse65falsetruefalse00falsefalsefalsetruefalse66falsetruefalse00falsefalsefalsetruefalse67falsetruefalse00falsefalsefalsetruefalse68falsetruefalse00falsefalsefalsetruefalse69falsetruefalse00falsefalsefalsetruefalse70falsetruefalse00falsefalsefalsetruefalse71falsetruefalse00falsefalsefalsetruefalse72falsetruefalse00falsefalsefalsetruefalse73falsetruefalse00falsefalsefalsetruefalse74falsetruefalse00falsefalsefalsetruefalse75falsetruefalse00falsefalsefalsetruefalse76falsetruefalse00falsefalsefalsetruefalse77falsetruefalse00falsefalsefalsetruefalse78falsetruefalse00falsefalsefalsetruefalse79falsetruefalse00falsefalsefalsetruefalse80falsetruefalse00falsefalsefalsetruefalse81falsetruefalse00falsefalsefalsetruefalse82falsetruefalse00falsefalsefalsetruefalseOtherus-types:percentItemTypepureThe percentage of the fair value of investment to the fair value of total plan asset category held as of the measurement date.No authoritative reference available.falsefalseComponents of plan asset categories1The mutual fund balance in the U.S. Pension Plans are invested in the following categories: 38% in the common stock of large-cap U.S. Companies, 27% in the common stock of international growth companies, and 35% in fixed income bonds issued by U.S. companies and by the U.S. Government and its Agencies.2Represents primarily amounts invested in common stock of technology, healthcare, financial, energy and consumer staples and discretionary U.S. companies.3Primarily represents money market funds held with various financial institutions. 4Hedge fund invests in both short and long term U.S. common stocks. Management of the hedge funds has the ability to shift investments from value to growth strategies, from large to small capitalization stocks and from a net long position to a net short position.5The mutual fund balance in the U.S. Retiree Healthcare Plan is invested in the following categories: 72% in the common stock of large-cap U.S. Companies, 9% in the common stock of international growth companies and 19% in fixed income bonds of U.S. companies and U.S. Government.6The mutual fund balance in the U.S. Retiree Healthcare Plan is invested in the following categories: 61% in the common stock of large-cap U.S. Companies, 12% in the common stock of international growth companies and 27% in fixed income bonds of U.S. companies and U.S. Government.7The mutual funds balance in the Non-U.S. Pension Plans is invested in international bonds.8Amount represents bank and insurance guaranteed investment contracts.823Retirement Plans (Details 10) (USD $)ThousandsUnKnownUnKnownUnKnowntruetrue