v3.6.0.2
Document and Entity Information - USD ($)
12 Months Ended
Jan. 01, 2017
Feb. 05, 2017
Jul. 03, 2016
Document Information [Line Items]      
Entity Registrant Name Kelly Services Inc    
Document Type 10-K    
Current Fiscal Year End Date --01-01    
Entity Public Float     $ 560,567,627
Amendment Flag false    
Entity Central Index Key 0000055135    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Accelerated Filer    
Entity Well-known Seasoned Issuer No    
Document Period End Date Jan. 01, 2017    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Class A common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   34,806,309  
Class B common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   3,437,643