Cover - USD ($)	12 Months Ended
	Dec. 31, 2021	Apr. 25, 2022	Jul. 03, 2021
Cover [Abstract]
Document Type	10-K/A
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity File Number	1-14315
Entity Registrant Name	Cornerstone Building Brands, Inc.
Entity Central Index Key	0000883902
Entity Tax Identification Number	76-0127701
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	5020 Weston Parkway
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Cary
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27513
City Area Code	866
Local Phone Number	419-0042
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CNR
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	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 966,794,672
Entity Common Stock, Shares Outstanding		127,329,476
ICFR Auditor Attestation Flag	true
Auditor Name	Grant Thornton LLP
Auditor Location	Raleigh, North Carolina
Auditor Firm ID	248