XML 12 R1.htm IDEA: XBRL DOCUMENT v3.19.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2019
Apr. 29, 2019
Document Information [Line Items]    
Entity Registrant Name KELLY SERVICES INC  
Document Type 10-Q  
Current Fiscal Year End Date --12-29  
Amendment Flag false  
Entity Central Index Key 0000055135  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Entity Emerging Growth Company false  
Entity Small Business false  
Class A Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   35,636,758
Class B Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   3,432,072