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

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

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-4

+ 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

Authorized for issuance under the dividend reinvestment plan

+ References

No definition available.

+ Details

Name:	wso_AuthorizedForIssuanceUnderTheDividendReinvestmentPlan
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

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_TwoThousandTwentyFourAtmProgramMember
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_AwardTypeAxis=wso_DividendReinvestmentPlanMember
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		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	May 31, 2024	Mar. 31, 2024
Stockholders Equity Note [Line Items]
Shares withheld as payment for tax withholdings related to share based compensation, market value			$ 1,403	$ 0
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		$ 400,000
Restricted Stock [Member]
Stockholders Equity Note [Line Items]
Shares withheld as payment for tax withholdings related to share based compensation, shares	2,206		3,637
Shares withheld as payment for tax withholdings related to share based compensation, market value	$ 813		$ 1,377
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	9,456	16,553	19,346	30,495
Common Stock [Member]
Stockholders Equity Note [Line Items]
Cash dividends paid per share of common stock	$ 3.3	$ 3	$ 6.3	$ 5.7
Common Stock [Member] \| Stock Option [Member]
Stockholders Equity Note [Line Items]
Shares withheld as payment for tax withholdings related to share based compensation, shares		2,232	589	2,232
Shares withheld as payment for tax withholdings related to share based compensation, market value		$ 1,067	$ 242	$ 1,067
Cash received from the exercise of stock options	$ 7,880	2,462	12,994	12,860
Common Stock [Member] \| Employee Stock Purchase Plan [Member]
Stockholders Equity Note [Line Items]
Net proceeds from shares purchased under ESPP	$ 612	$ 582	$ 1,260	$ 1,233