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