Other Commitments and Contingencies Additional Information (Detail) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Future Minimum License Fees Payable	Future minimum license fees payable under existing license agreements as of December 31, 2019 are immaterial for the years ended December 31, 2020 and thereafter.
Potentials Payments Under Licensing Arrangements	$ 7

The amount of additional payments that could be required for the achievement of certain milestones under a licensing agreement.

No definition available.

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