v3.3.1.900
Document and Entity Information - USD ($)
12 Months Ended
Jan. 03, 2016
Feb. 07, 2016
Jun. 28, 2015
Document Information [Line Items]      
Entity Registrant Name Kelly Services Inc    
Document Type 10-K    
Current Fiscal Year End Date --01-03    
Entity Public Float     $ 486,699,653
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. 03, 2016    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Class A common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   34,551,823  
Class B common stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   3,439,161