Cover - shares	8 Months Ended
	Sep. 30, 2020	Nov. 04, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-39277
Entity Registrant Name	FORTRESS VALUE ACQUISITION CORP.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4465489
Entity Address, Address Line One	1345 Avenue of the Americas
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10105
City Area Code	212
Local Phone Number	798-6100
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	true
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001801368
Current Fiscal Year End Date	--12-31
Common Class A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		34,500,000
Common Class F
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		8,625,000
New York Stock Exchange | Units, each consisting of one share of Class A common stock and one-third of one redeemable warrant
Entity Information [Line Items]
Title of 12(b) Security	Units, each consisting of one share of Class A common stock and one-third of one redeemable warrant
Trading Symbol	FVAC.U
Security Exchange Name	NYSE
New York Stock Exchange | Common Class A
Entity Information [Line Items]
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	FVAC
Security Exchange Name	NYSE
New York Stock Exchange | Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 per share
Entity Information [Line Items]
Title of 12(b) Security	Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 per share
Trading Symbol	FVAC WS
Security Exchange Name	NYSE