Business Segment Information - Summary of Net Sales for Company's Products and Services (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total net sales	$ 715,019	$ 578,021	$ 596,219	$ 530,670	$ 687,275	$ 565,584	$ 558,250	$ 497,969	$ 2,419,929	$ 2,309,078	$ 2,167,423
Waters Instrument Systems [Member]
Disaggregation of Revenue [Line Items]
Total net sales									1,000,625	988,750	943,218
Chemistry Consumables [Member]
Disaggregation of Revenue [Line Items]
Total net sales									400,287	372,157	345,413
TA Instrument Systems [Member]
Disaggregation of Revenue [Line Items]
Total net sales									204,081	191,442	171,665
Product [Member]
Disaggregation of Revenue [Line Items]
Total net sales									1,604,993	1,552,349	1,460,296
Waters Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales									738,433	686,656	639,432
TA Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales									76,503	70,073	67,695
Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales									$ 814,936	$ 756,729	$ 707,127