v3.26.1
Cover
Jun. 29, 2026
Document Information [Line Items]  
Entity Registrant Name Alight, Inc. / Delaware
Amendment Flag false
Current Fiscal Year End Date --12-31
Entity Central Index Key 0001809104
Document Type 8-K
Document Period End Date Jun. 29, 2026
Entity Incorporation, State or Country Code DE
Entity File Number 001-39299
Entity Tax Identification Number 86-1849232
Entity Address, Address Line One 510 Lake Cook Road,
Entity Address, Address Line Two Suite 400
Entity Address, City or Town Deerfield
Entity Address, State or Province IL
Entity Address, Postal Zip Code 60015
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
Former Address  
Document Information [Line Items]  
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