Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Mar. 27, 2023	Jul. 01, 2022
Cover [Abstract]
Document Type	10-K/A
Amendment Flag	true
Amendment Description	On March 31, 2023, Williams Industrial Services Group Inc. ("Williams," the "Company," "we," "us," or "our") filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (the "Original Form 10-K") with the U.S. Securities and Exchange Commission (the "SEC"). We are filing this Annual Report on Form 10-K/A (this "Amendment") as Amendment No. 1 to the Original Form 10-K for the purposes of amending Part III, Items 10, 11, 12, 13 and 14 of the Original Form 10-K to include the information required by such Items. This information was previously omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K. This Amendment amends and restates in their entirety Items 10, 11, 12, 13 and 14 of Part III of the Original Form 10-K.
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2022
Current Fiscal Year End Date	--12-31
Entity File Number	001-16501
Entity Registrant Name	Williams Industrial Services Group Inc.
Entity Central Index Key	0001136294
Entity Tax Identification Number	73-1541378
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	200 Ashford Center North
Entity Address, Address Line Two	Suite 425
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30338
City Area Code	770
Local Phone Number	879-4400
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	WLMS
Security Exchange Name	NYSE
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			$ 23,197,687
Entity Common Stock, Shares Outstanding		27,058,317
ICFR Auditor Attestation Flag	false
Auditor Name	Moss Adams LLP
Auditor Location	Dallas, Texas
Auditor Firm ID	659

Williams Industrial Services Group Inc. 10-K/A