2.2.0.25falsefalse10020 - Statement - Consolidated Statements of OperationstruefalseIn Thousands, except Per Share datafalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $FROM_Jan01_2010_TO_Dec31_2010http://www.sec.gov/CIK0001000697duration2010-01-01T00:00:002010-12-31T00:00:00SharesStandardhttp://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$2falsefalseUSDfalsefalse1/1/2009 - 12/31/2009 USD ($) USD ($) / shares $FROM_Jan01_2009_TO_Dec31_2009http://www.sec.gov/CIK0001000697duration2009-01-01T00:00:002009-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0EPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDfalsefalse1/1/2008 - 12/31/2008 USD ($) USD ($) / shares $FROM_Jan01_2008_TO_Dec31_2008http://www.sec.gov/CIK0001000697duration2008-01-01T00:00:002008-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170EPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2true0us-gaap_IncomeStatementAbstractus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseIncome Statement [Abstract]3false0us-gaap_SalesRevenueGoodsNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse11666270001166627falsetruefalsefalsefalse2truefalsefalse10519780001051978falsetruefalsefalsefalse3truefalsefalse11398860001139886falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 falsefalseProduct sales4false0us-gaap_SalesRevenueServicesNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse476744000476744falsefalsefalsefalsefalse2truefalsefalse446722000446722falsefalsefalsefalsefalse3truefalsefalse435238000435238falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 truefalseService sales5false0us-gaap_SalesRevenueNetus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse16433710001643371falsefalsefalsefalsefalse2truefalsefalse14987000001498700falsefalsefalsefalsefalse3truefalsefalse15751240001575124falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 falsefalseTotal net sales6false0us-gaap_CostOfGoodsSoldus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse453779000453779falsefalsefalsefalsefalse2truefalsefalse406681000406681falsefalsefalsefalsefalse3truefalsefalse457886000457886falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal costs related to goods produced and sold during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 2 -Article 5 falsefalseCost of product sales7false0us-gaap_CostOfServicesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse199524000199524falsefalsefalsefalsefalse2truefalsefalse188201000188201falsefalsefalsefalsefalse3truefalsefalse203380000203380falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal costs related to services rendered by an entity during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 2 -Article 5 truefalseCost of service sales8false0us-gaap_CostOfGoodsAndServicesSoldus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse653303000653303falsefalsefalsefalsefalse2truefalsefalse594882000594882falsefalsefalsefalsefalse3truefalsefalse661266000661266falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 2 -Article 5 truefalseTotal cost of sales9false0us-gaap_GrossProfitus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse990068000990068falsefalsefalsefalsefalse2truefalsefalse903818000903818falsefalsefalsefalsefalse3truefalsefalse913858000913858falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.No authoritative reference available.falsefalseGross profit10false0us-gaap_SellingGeneralAndAdministrativeExpenseus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse445456000445456falsefalsefalsefalsefalse2truefalsefalse421403000421403falsefalsefalsefalsefalse3truefalsefalse426699000426699falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 4 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 4 -Paragraph 5A falsefalseSelling and administrative expenses11false0us-gaap_ResearchAndDevelopmentExpenseus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse8427400084274falsefalsefalsefalsefalse2truefalsefalse7715400077154falsefalsefalsefalsefalse3truefalsefalse8158800081588falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph g Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 2 -Paragraph 12, 13 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 86 -Paragraph 11, 12 falsefalseResearch and development expenses12false0wat_PurchasedIntangiblesAmortizationwatfalsedebitdurationThe aggregate expense charged against earnings to allocate the cost of intangible assets acquired (nonphysical assets not...falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse1040600010406falsefalsefalsefalsefalse2truefalsefalse1065900010659falsefalsefalsefalsefalse3truefalsefalse92900009290falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate expense charged against earnings to allocate the cost of intangible assets acquired (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.No authoritative reference available.falsefalsePurchased intangibles amortization13false0us-gaap_GainLossRelatedToLitigationSettlementus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegatedtotal1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsefalse65270006527falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net proceeds or assets obtained in excess of (less than) the net carrying amount of assets recorded, or assets distributed and liabilities assumed less than (in excess of) litigation reserves extinguished, in settlement of a litigation matter. Represents (for other than an insurance entity in its normal claims settlement process), the amount of income (expense) recognized in the period to settle pending or threatened litigation and insurance claims.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9, 10, 11, 12 truefalseLitigation provisions (Note 10)14false0us-gaap_OperatingIncomeLossus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse449932000449932falsefalsefalsefalsefalse2truefalsefalse394602000394602falsefalsefalsefalsefalse3truefalsefalse389754000389754falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe net result for the period of deducting operating expenses from operating revenues.No authoritative reference available.falsefalseOperating income15false0us-gaap_InterestExpenseus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse-13924000-13924falsefalsefalsefalsefalse2truefalsefalse-10986000-10986falsefalsefalsefalsefalse3truefalsefalse-38521000-38521falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe cost of borrowed funds accounted for as interest that was charged against earnings during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher OTS -Name Federal Regulation (FR) -Number Title 12 -Chapter V -Section 563c.102 -Paragraph 9 -Subsection II Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 9 -Article 9 falsefalseInterest expense16false0us-gaap_InvestmentIncomeInterestus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse18550001855falsefalsefalsefalsefalse2truefalsefalse30360003036falsefalsefalsefalsefalse3truefalsefalse2095900020959falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncome derived from investments in debt securities and on cash and cash equivalents the earnings of which reflect the time value of money or transactions in which the payments are for the use or forbearance of money.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 truefalseInterest income17false0us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse437863000437863falsefalsefalsefalsefalse2truefalsefalse386652000386652falsefalsefalsefalsefalse3truefalsefalse372192000372192falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetarySum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 falsefalseIncome from operations before income taxes18false0us-gaap_IncomeTaxExpenseBenefitus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse5610000056100falsefalsefalsefalsefalse2truefalsefalse6333900063339falsefalsefalsefalsefalse3truefalsefalse4971300049713falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b truefalseProvision for income taxes19false0us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterestus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse381763000381763falsetruefalsefalsefalse2truefalsefalse323313000323313falsetruefalsefalsefalse3truefalsefalse322479000322479falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 truefalseNet income20false0us-gaap_IncomeLossFromContinuingOperationsPerBasicShareus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse4.134.13falsetruefalsefalsefalse2truefalsefalse3.373.37falsetruefalsefalsefalse3truefalsefalse3.253.25falsetruefalsefalsefalseEPSus-types:perShareItemTypedecimalThe amount of income (loss) from continuing operations per each share of common stock outstanding during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 21 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 36, 37, 38 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 18 -Article 7 falsetrueNet income per basic common share21false0us-gaap_WeightedAverageNumberOfSharesOutstandingBasicus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse9238500092385falsefalsefalsefalsefalse2truefalsefalse9579700095797falsefalsefalsefalsefalse3truefalsefalse9919900099199falsefalsefalsefalsefalseSharesxbrli:sharesItemTypesharesNumber of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 171 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 8 falsefalseWeighted-average number of basic common shares22false0us-gaap_IncomeLossFromContinuingOperationsPerDilutedShareus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse4.064.06falsetruefalsefalsefalse2truefalsefalse3.343.34falsetruefalsefalsefalse3truefalsefalse3.213.21falsetruefalsefalsefalseEPSus-types:perShareItemTypedecimalThe amount of income (loss) from continuing operations available to each share of common stock outstanding during the reporting period and each share that would have been outstanding assuming the issuance of common shares for all dilutive potential common shares outstanding during the reporting period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 21 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 11, 12, 36, 37, 38 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 18 -Article 7 falsetrueNet income per diluted common share23false0us-gaap_WeightedAverageNumberOfDilutedSharesOutstandingus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse9405700094057falsefalsefalsefalsefalse2truefalsefalse9686200096862falsefalsefalsefalsefalse3truefalsefalse100555000100555falsefalsefalsefalsefalseSharesxbrli:sharesItemTypesharesThe average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 8 falsefalseWeighted-average number of diluted common shares and equivalents322Consolidated Statements of Operations (USD $)ThousandsThousandsNoRoundingUnKnownfalsetrue