Segment Disclosures - Segment Revenue From Service (Details) - Service - USD ($) $ in Millions	3 Months Ended
	Apr. 02, 2023	Apr. 03, 2022
Revenue from Services
Segment revenue from services	$ 1,268.3	$ 1,296.4
Less: Intersegment revenue
Revenue from Services
Segment revenue from services	(3.7)	(0.3)
Professional & Industrial | Reporting Segments
Revenue from Services
Segment revenue from services	389.8	444.3
Science, Engineering & Technology | Reporting Segments
Revenue from Services
Segment revenue from services	306.4	317.1
Education | Reporting Segments
Revenue from Services
Segment revenue from services	249.4	173.4
Outsourcing & Consulting | Reporting Segments
Revenue from Services
Segment revenue from services	114.6	109.1
International | Reporting Segments
Revenue from Services
Segment revenue from services	$ 211.8	$ 252.8