XML 17 R1.htm IDEA: XBRL DOCUMENT v3.20.4
Cover Page - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2020
Mar. 01, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 1-13948    
Entity Registrant Name SCHWEITZER-MAUDUIT INTERNATIONAL, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 62-1612879    
Entity Address, Address Line One 100 North Point Center East,    
Entity Address, Address Line Two Suite 600    
Entity Address, Postal Zip Code 30022    
Entity Address, City or Town Alpharetta,    
Entity Address, State or Province GA    
City Area Code 800    
Local Phone Number 514-0186    
Title of 12(b) Security Common stock, $0.10 par value    
Trading Symbol SWM    
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    
Entity Public Float     $ 1.0
Entity Common Stock, Shares Outstanding   31,415,733  
Documents incorporated by reference Portions of the registrant's definitive Proxy Statement relating to its 2021 Annual Meeting of Stockholders scheduled to be held on April 22, 2021 (the "2021 Proxy Statement") and filed pursuant to Regulation 14A are incorporated by reference into Part III of this Annual Report on Form 10-K.    
Entity Central Index Key 0001000623    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false