Annual report [Section 13 and 15(d), not S-K Item 405]

Cover

v3.25.4
Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Feb. 20, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-38221    
Entity Registrant Name Ecovyst Inc.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 81-3406833    
Entity Address, Address Line One 600 Lee Road, Suite 200    
Entity Address, City or Town Wayne    
Entity Address, State or Province PA    
Entity Address, Postal Zip Code 19087    
City Area Code (484)    
Local Phone Number 617-1200    
Title of 12(b) Security Common stock, par value $0.01 per share    
Trading Symbol ECVT    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
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    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Document Financial Statement Error Correction false    
Entity Public Float     $ 932,918,934
Entity Common Stock, Shares Outstanding   110,586,098  
Documents Incorporated by Reference
Portions of the Ecovyst Inc. Proxy Statement for the 2026 Annual Meeting of Stockholders are incorporated by reference into Part III of this report.
    
Entity Central Index Key 0001708035    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false