Name:	wat_CashEquivalentsAndInvestmentsAmortizedCostBasis
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of debt securities at fair value maturing in the next rolling twelve months following the latest balance sheet presented.

No definition available.

Name:	wat_CashEquivalentsAndInvestmentsDebtMaturitiesNextRollingTwelveMonthsFairValue
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of debt securities at fair value maturing in the second rolling twelve months through the fifth rolling twelve months following the latest balance sheet presented.

No definition available.

Name:	wat_CashEquivalentsAndInvestmentsDebtMaturitiesRollingYearTwoThroughFiveFairValue
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents cash equivalents and short-term investments as of the balance sheet date.

No definition available.

Name:	wat_CashEquivalentsAndInvestmentsFairValue
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the gross unrealized gains for securities, at a point in time.

No definition available.

Name:	wat_CashEquivalentsAndInvestmentsGrossUnrealizedGains
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the gross unrealized losses for securities, at a point in time.

No definition available.

Name:	wat_CashEquivalentsAndInvestmentsGrossUnrealizedLosses
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	wat_CashEquivalentsAndInvestmentsLineItems
Namespace Prefix:	wat_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Bonds or similar securities.

No definition available.

Name:	wat_DebtSecurities
Namespace Prefix:	wat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsClassificationAxis=us-gaap_CashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsClassificationAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsTypeAxis=us-gaap_BankTimeDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsTypeAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsTypeAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	wat_CashCashEquivalentsAndShortTermInvestmentsTypeAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: