XML 20 R1.htm IDEA: XBRL DOCUMENT v3.20.4
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Feb. 18, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2020    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Trading Symbol GLT    
Entity Registrant Name Glatfelter Corporation    
Entity Central Index Key 0000041719    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Interactive Data Current Yes    
Entity File Number 1-03560    
Entity Tax Identification Number 23-0628360    
Entity Address, Address Line One 4350 Congress Street    
Entity Address, Address Line Two Suite 600    
Entity Address, City or Town Charlotte    
Entity Address, State or Province NC    
Entity Address, Postal Zip Code 28209    
City Area Code 704    
Local Phone Number 885-2555    
Document Annual Report true    
Document Transition Report false    
Title of 12(b) Security Common Stock, par value $.01 per share    
Security Exchange Name NYSE    
Entity Incorporation, State or Country Code PA    
Entity Common Stock, Shares Outstanding   44,367,836  
Entity Public Float     $ 691.3
Documents Incorporated by Reference

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the definitive Proxy Statement to be delivered to shareholders in connection with the Annual Meeting of Shareholders to be held on May 6, 2021 are incorporated by reference into Part III.