1.0.0.3 false Consolidated Statements of Cash Flows (USD $) In Thousands false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 false 3 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 7 Cash flows from operating activities: 5 us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 8 Net income 6 us-gaap_ProfitLoss us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 323313000 323313 false false 2 true true 322479000 322479 false false 3 true true 268072000 268072 false false No definition available. No authoritative reference available. false 10 Adjustments to reconcile net income to net cash provided by operating activities: 7 us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 11 Provisions for doubtful accounts on accounts receivable 8 us-gaap_ProvisionForDoubtfulAccounts us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3124000 3124 false false 2 false true 3924000 3924 false false 3 false true 1382000 1382 false false No definition available. No authoritative reference available. false 12 Provisions on inventory 8 us-gaap_InventoryWriteDown us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 9952000 9952 false false 2 false true 10632000 10632 false false 3 false true 6024000 6024 false false No definition available. No authoritative reference available. false 13 Stock-based compensation 8 us-gaap_ShareBasedCompensation us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 28255000 28255 false false 2 false true 30782000 30782 false false 3 false true 28855000 28855 false false No definition available. No authoritative reference available. false 14 Deferred income taxes 8 us-gaap_DeferredIncomeTaxExpenseBenefit us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 36276000 36276 false false 2 false true -19626000 -19626 false false 3 false true 5946000 5946 false false No definition available. No authoritative reference available. false 15 Depreciation 8 us-gaap_Depreciation us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 31805000 31805 false false 2 false true 29071000 29071 false false 3 false true 27467000 27467 false false No definition available. No authoritative reference available. false 16 Amortization of intangibles 8 us-gaap_AmortizationOfIntangibleAssets us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 25467000 25467 false false 2 false true 36200000 36200 false false 3 false true 25850000 25850 false false No definition available. No authoritative reference available. false 17 Change in operating assets and liabilities, net of acquisitions: 7 us-gaap_IncreaseDecreaseInOperatingCapitalAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 18 (Increase) decrease in accounts receivable 8 us-gaap_IncreaseDecreaseInAccountsReceivable us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -16905000 -16905 false false 2 false true 21739000 21739 false false 3 false true -26266000 -26266 false false No definition available. No authoritative reference available. false 19 Increase in inventories 8 us-gaap_IncreaseDecreaseInInventories us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -6823000 -6823 false false 2 false true -20618000 -20618 false false 3 false true -6368000 -6368 false false No definition available. No authoritative reference available. false 20 Decrease (increase) in other current assets 8 us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 5925000 5925 false false 2 false true -4633000 -4633 false false 3 false true -3032000 -3032 false false No definition available. No authoritative reference available. false 21 (Increase) decrease in other assets 8 us-gaap_IncreaseDecreaseInOtherOperatingAssets us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -689000 -689 false false 2 false true 5180000 5180 false false 3 false true -6600000 -6600 false false No definition available. No authoritative reference available. false 22 (Decrease) increase in accounts payable and other current liabilities 8 us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -10830000 -10830 false false 2 false true -19970000 -19970 false false 3 false true 32309000 32309 false false No definition available. No authoritative reference available. false 23 Increase in deferred revenue and customer advances 8 wat_IncreaseInDeferredRevenueAndCustomerAdvances wat false debit duration monetary Increase in deferred revenue and customer advances false false false false false false false false false 1 false true 2613000 2613 false false 2 false true 1976000 1976 false false 3 false true 6244000 6244 false false Increase in deferred revenue and customer advances No authoritative reference available. false 24 (Decrease) increase in other liabilities 8 us-gaap_IncreaseDecreaseInOtherOperatingLiabilities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -13220000 -13220 false false 2 false true 21112000 21112 false false 3 false true 10624000 10624 false false No definition available. No authoritative reference available. true 25 Net cash provided by operating activities 5 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true 418263000 418263 false false 2 false true 418248000 418248 false false 3 false true 370507000 370507 false false No definition available. No authoritative reference available. false 27 Cash flows from investing activities: 5 us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 28 Additions to property, plant, equipment and software capitalization 6 wat_AdditionsToPropertyPlantEquipmentAndSoftwareCapitalization wat false credit duration monetary Additions to property, plant, equipment and software capitalization false false false false false false false false false 1 false true -93796000 -93796 false false 2 false true -69065000 -69065 false false 3 false true -60342000 -60342 false false Additions to property, plant, equipment and software capitalization No authoritative reference available. false 29 Business acquisitions, net of cash acquired 6 us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -36086000 -36086 false false 2 false true -7805000 -7805 false false 3 false true -9076000 -9076 false false No definition available. No authoritative reference available. false 30 Investment in unaffiliated company 6 us-gaap_PaymentsToAcquireOtherInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false 3 false true -3532000 -3532 false false No definition available. No authoritative reference available. false 31 Purchase of short-term investments 6 us-gaap_PaymentsToAcquireShortTermInvestments us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -518390000 -518390 false false 2 false true -19738000 -19738 false false 3 false true -390542000 -390542 false false No definition available. No authoritative reference available. false 32 Maturity of short-term investments 6 us-gaap_ProceedsFromSaleOfShortTermInvestments us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 229244000 229244 false false 2 false true 115419000 115419 false false 3 false true 294861000 294861 false false No definition available. No authoritative reference available. false 33 Cash received from escrow related to business acquisition 6 us-gaap_PaymentsForProceedsFromPreviousAcquisition us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false 3 false true 724000 724 false false No definition available. No authoritative reference available. true 34 Net cash (used in) provided by investing activities 5 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -419028000 -419028 false false 2 false true 18811000 18811 false false 3 false true -167907000 -167907 false false No definition available. No authoritative reference available. false 36 Cash flows from financing activities: 5 us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false No definition available. false 37 Proceeds from debt issuances 6 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 184309000 184309 false false 2 false true 469407000 469407 false false 3 false true 1131834000 1131834 false false No definition available. No authoritative reference available. false 38 Payments on debt 6 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -92556000 -92556 false false 2 false true -817463000 -817463 false false 3 false true -1151119000 -1151119 false false No definition available. No authoritative reference available. false 39 Payments of debt issuance costs 6 us-gaap_PaymentsOfDebtIssuanceCosts us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true -501000 -501 false false 3 false true -1081000 -1081 false false No definition available. No authoritative reference available. false 40 Proceeds from stock plans 6 us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 19099000 19099 false false 2 false true 28646000 28646 false false 3 false true 91427000 91427 false false No definition available. No authoritative reference available. false 41 Purchase of treasury shares 6 us-gaap_PaymentsForRepurchaseOfCommonStock us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true -211377000 -211377 false false 2 false true -237500000 -237500 false false 3 false true -200648000 -200648 false false No definition available. No authoritative reference available. false 42 Excess tax benefit related to stock option plans 6 us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 5083000 5083 false false 2 false true 6669000 6669 false false 3 false true 16999000 16999 false false No definition available. No authoritative reference available. false 43 Proceeds (payments) of debt swaps and other derivative contracts 6 wat_PaymentsOfDebtSwapsAndOtherDerivativeContracts wat false debit duration monetary Payments of debt swaps and other derivative contracts false false false false false false false false false 1 false true 5162000 5162 false false 2 false true -22196000 -22196 false false 3 false true -7098000 -7098 false false Payments of debt swaps and other derivative contracts No authoritative reference available. true 44 Net cash used in financing activities 5 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true -90280000 -90280 false false 2 false true -572938000 -572938 false false 3 false true -119686000 -119686 false false No definition available. No authoritative reference available. false 45 Effect of exchange rate changes on cash and cash equivalents 4 us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents us-gaap true debit duration monetary No definition available. false false false false false false false false false 1 false true 3634000 3634 false false 2 false true -32932000 -32932 false false 3 false true 253000 253 false false No definition available. No authoritative reference available. true 46 (Decrease) increase in cash and cash equivalents 4 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration monetary No definition available. false false false false false false false false false 1 false true -87411000 -87411 false false 2 false true -168811000 -168811 false false 3 false true 83167000 83167 false false No definition available. No authoritative reference available. false 47 Cash and cash equivalents at beginning of period 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false true false false 1 false true 428522000 428522 false false 2 false true 597333000 597333 false false 3 false true 514166000 514166 false false No definition available. No authoritative reference available. false 48 Cash and cash equivalents at end of period 3 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false true false 1 false true 341111000 341111 false false 2 false true 428522000 428522 false false 3 false true 597333000 597333 false false No definition available. No authoritative reference available. false 49 Supplemental cash flow information: 3 wat_SupplementalCashFlowInformation wat false na duration string Supplemental cash flow information: false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false 3 false false 0 0 false false Supplemental cash flow information: false 50 Income taxes paid 4 us-gaap_IncomeTaxesPaid us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 false true 23818000 23818 false false 2 false true 40571000 40571 false false 3 false true 29294000 29294 false false No definition available. No authoritative reference available. false 51 Interest paid 4 us-gaap_InterestPaid us-gaap true credit duration monetary No definition available. false false false false false false false false false 1 true true 13020000 13020 false false 2 true true 44081000 44081 false false 3 true true 49224000 49224 false false No definition available. No authoritative reference available. false false 3 42 false Thousands UnKnown UnKnown false true