Quarterly report pursuant to Section 13 or 15(d)


Cover - shares
9 Months Ended
Sep. 30, 2021
Nov. 15, 2021
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2021  
Document Transition Report false  
Entity File Number 001-40887  
Entity Registrant Name Life Time Group Holdings, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 47-3481985  
Entity Address, Address Line One 2902 Corporate Place  
Entity Address, City or Town Chanhassen  
Entity Address, State or Province MN  
Entity Address, Postal Zip Code 55317  
City Area Code 952  
Local Phone Number 947-0000  
Title of 12(b) Security Common stock, par value $0.01 per share  
Trading Symbol LTH  
Security Exchange Name NYSE  
Entity Current Reporting Status No  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   193,059,950
Entity Central Index Key 0001869198  
Amendment Flag false  
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2021  
Current Fiscal Year End Date --12-31