Aggregate dividends paid during the period for each share of common stock outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

+ Details

Name:	us-gaap_CommonStockDividendsPerShareCashPaid
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

+ Details

Name:	us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow from issuance of shares under share-based payment arrangement. Includes, but is not limited to, option exercised.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Subparagraph (a)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2A

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from the issuance of an equity stock that has been previously reacquired by the entity.

+ References

+ Details

Name:	us-gaap_ProceedsFromSaleOfTreasuryStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_ProceedsFromStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Available for issuance under the dividend reinvestment plan.

+ References

No definition available.

+ Details

Name:	wso_AvailableForIssuanceUnderTheDividendReinvestmentPlan
Namespace Prefix:	wso_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Available for sale under AT-the-Market offering program.

+ References

No definition available.

+ Details

Name:	wso_AvailableForSaleUnderAtmOfferingProgram
Namespace Prefix:	wso_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cumulative value of common stock sold under the 2021 ATM program.

+ References

No definition available.

+ Details

Name:	wso_CumulativeValueOfCommonStockSoldUnderThe2021AtmProgram
Namespace Prefix:	wso_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Direct costs.

+ References

No definition available.

+ Details

Name:	wso_DirectCosts
Namespace Prefix:	wso_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum aggregate offering amount of stock.

+ References

No definition available.

+ Details

Name:	wso_MaximumAggregateOfferingAmountOfStock
Namespace Prefix:	wso_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Stockholders Equity Note [Line Items]

+ References

No definition available.

+ Details

Name:	wso_StockholdersEquityNoteLineItems
Namespace Prefix:	wso_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	wso_ProgramNameAxis=wso_TwoThousandTwentyOneAtmProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	wso_ProgramNameAxis=wso_TwoThousandTwentyFourAtmProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=wso_DividendReinvestmentPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=wso_CommonAndClassBCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=wso_EmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	May 03, 2024	Mar. 29, 2024	Aug. 06, 2021
Stockholders Equity Note [Line Items]
Net proceeds from the sale of Common stock	$ 0	$ 281,784
Shares withheld as payment for tax withholdings related to share based compensation, market value	0	442
2021 ATM Program [Member]
Stockholders Equity Note [Line Items]
Net proceeds from the sale of Common stock		281,784
Maximum aggregate offering amount of stock					$ 300,000
Cumulative value of Common Stock sold under the 2021 ATM Program		298,455
Direct costs		$ 33
Number of shares sold and issued under ATM		712,000
2024 ATM Program [Member]
Stockholders Equity Note [Line Items]
Maximum aggregate offering amount of stock			$ 400,000
Available for sale under ATM Program	$ 400,000
Dividend Reinvestment Plan [Member]
Stockholders Equity Note [Line Items]
Authorized shares of each of Common and Class B available for issuance under the Dividend Reinvestment Plan				300,000
Stock issued during period, shares, dividend reinvestment plan	13,942
Common and Class B Common Stock [Member] \| Restricted Stock [Member]
Stockholders Equity Note [Line Items]
Shares withheld as payment for tax withholdings related to share based compensation, shares		999
Shares withheld as payment for tax withholdings related to share based compensation, market value		$ 390
Common Stock [Member]
Stockholders Equity Note [Line Items]
Cash dividends paid per share of common stock	$ 2.7	$ 2.45
Common Stock [Member] \| Stock Option [Member]
Stockholders Equity Note [Line Items]
Shares withheld as payment for tax withholdings related to share based compensation, shares		426
Shares withheld as payment for tax withholdings related to share based compensation, market value		$ 175
Cash received from the exercise of stock options	$ 10,398	10,040
Common Stock [Member] \| Employee Stock Purchase Plan [Member]
Stockholders Equity Note [Line Items]
Net proceeds from shares purchased under ESPP	$ 651	$ 583