2.2.0.7 false Earnings Per Share (Policies) 20900 - Disclosure - Earnings Per Share (Policies) true false false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Earnings Per Share (Policies) [Abstract] 0 wat_EarningsPerSharePoliciesAbstract wat false na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 3 Earnings Per Share Policy 1 us-gaap_EarningsPerSharePolicyTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <p style='margin-top:0pt; margin-bottom:0pt'><font style="font-family:Times New Roman;font-size:10pt;margin-left:0px;">The effect of dilutive securities was calculated using the treasury stock method.</font></p> The effect of dilutive securities was calculated using the treasury stock method. false false false us-types:textBlockItemType textblock Discloses the methodology and assumptions used to compute basic and diluted earnings (loss) per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements. 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 6, 8-16, 60 false 1 2 false UnKnown UnKnown UnKnown false true