XML 49 R1.htm IDEA: XBRL DOCUMENT v3.25.0.1
Document and Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 29, 2024
Feb. 02, 2025
Jun. 30, 2024
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Current Fiscal Year End Date --12-29    
Document Period End Date Dec. 29, 2024    
Document Transition Report false    
Entity File Number 0-1088    
Entity Registrant Name KELLY SERVICES, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 38-1510762    
Entity Address, Address Line One 999 West Big Beaver Road    
Entity Address, City or Town Troy    
Entity Address, State or Province MI    
Entity Address, Postal Zip Code 48084    
City Area Code 248    
Local Phone Number 362-4444    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 677.0
Documents Incorporated by Reference
Portions of the proxy statement of the registrant with respect to its 2025 Annual Meeting of Stockholders are incorporated by reference in Part III of this Form 10-K to the extent described herein.
    
Amendment Flag false    
Entity Central Index Key 0000055135    
Document Fiscal Year Focus 2024    
Document Fiscal Period Focus FY    
Auditor Name PricewaterhouseCoopers LLP    
Auditor Location Detroit, Michigan    
Auditor Firm ID 238    
Class A common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   31,592,205  
Class B common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   3,295,841  
NASDAQ Global Market | Class A common stock      
Document Information [Line Items]      
Title of 12(b) Security Class A Common Stock, $1.00 par value per share    
Trading Symbol KELYA    
Security Exchange Name NASDAQ    
NASDAQ Global Market | Class B common stock      
Document Information [Line Items]      
Title of 12(b) Security Class B Common Stock, $1.00 par value per share    
Trading Symbol KELYB    
Security Exchange Name NASDAQ