Segment Disclosures - Segment Revenue Per Service (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Jan. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Jan. 03, 2016	[1]	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Jan. 01, 2017	Jan. 03, 2016		Dec. 28, 2014
Revenue from Services:
Segment revenue for service	$ 1,304.4	$ 1,247.8	$ 1,375.5	$ 1,349.1	$ 1,461.6		$ 1,351.0	$ 1,385.0	$ 1,320.6	$ 5,276.8	$ 5,518.2	[2]	$ 5,562.7
Reporting Segments | Total Americas Commercial and PT
Revenue from Services:
Segment revenue for service										3,495.1	3,576.2		3,565.6
Reporting Segments | Total EMEA Commercial and PT
Revenue from Services:
Segment revenue for service										938.1	945.0		1,085.0
Reporting Segments | Total APAC Commercial and PT
Revenue from Services:
Segment revenue for service										189.0	387.7		392.2
Reporting Segments | Americas Commercial
Revenue from Services:
Segment revenue for service										2,548.0	2,604.3		2,609.6
Reporting Segments | Americas PT
Revenue from Services:
Segment revenue for service										947.1	971.9		956.0
Reporting Segments | EMEA Commercial
Revenue from Services:
Segment revenue for service										769.3	773.5		894.7
Reporting Segments | EMEA PT
Revenue from Services:
Segment revenue for service										168.8	171.5		190.3
Reporting Segments | APAC Commercial
Revenue from Services:
Segment revenue for service										170.7	347.2		351.8
Reporting Segments | APAC PT
Revenue from Services:
Segment revenue for service										18.3	40.5		40.4
Reporting Segments | OCG
Revenue from Services:
Segment revenue for service										706.4	673.8		586.8
Less: Intersegment revenue
Revenue from Services:
Segment revenue for service										$ (51.8)	$ (64.5)		$ (66.9)

[1] Fourth Quarter 2015 included 14 weeks.

[2] Fiscal year included 53 weeks.