v3.26.1
Document And Entity Information
Jun. 04, 2026
Jun. 03, 2026
Cover [Abstract]    
Entity Registrant Name Alight, Inc. / Delaware  
Amendment Flag false  
Entity Central Index Key 0001809104  
Document Type 8-K  
Document Period End Date   Jun. 03, 2026
Entity Incorporation, State or Country Code DE  
Entity File Number 001-39299  
Entity Tax Identification Number 86-1849232  
Entity Address, Address Line One 320 South Canal Street,  
Entity Address, Address Line Two 50th Floor  
Entity Address, Address Line Three Suite 5000  
Entity Address, City or Town Chicago  
Entity Address, State or Province IL  
Entity Address, Postal Zip Code 60606  
City Area Code (224)  
Local Phone Number 737-7000  
Written Communications false  
Soliciting Material false  
Pre-commencement Tender Offer false  
Pre-commencement Issuer Tender Offer false  
Title of 12(b) Security Class A Common Stock, par value $0.0001 per share  
Trading Symbol ALIT  
Security Exchange Name NYSE  
Entity Emerging Growth Company false