Cover - USD ($)	12 Months Ended
	Dec. 31, 2024	Feb. 26, 2025
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2024
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2024
Current Fiscal Year End Date	--12-31
Entity File Number	000-53177
Entity Registrant Name	Ridgewood Energy W Fund, LLC
Entity Central Index Key	0001409947
Entity Tax Identification Number	26-0225130
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	103 Foulk Road
Entity Address, City or Town	Wilmington
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19803
City Area Code	800
Local Phone Number	942-5550
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float	$ 0
Entity Common Stock, Shares Outstanding		332.2918
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Morristown, New Jersey