Contingencies - Narrative (Details) (Robert and Margaret Ward vs. Jefferson Parish School Board and Kelly Services, USD $) In Millions, unless otherwise specified	3 Months Ended	1 Months Ended	3 Months Ended
	Mar. 29, 2015	Apr. 30, 2014	Dec. 29, 2013
Loss Contingencies [Line Items]
Reduction in accrual for litigation costs	$ 1.7
Judgement Against Jefferson Parish School Board and Kelly Services
Loss Contingencies [Line Items]
Damages sought by plaintiff			4.4
Settlement amount		1.0
Kelly Services Share
Loss Contingencies [Line Items]
Damages sought by plaintiff			$ 2.7