Goodwill and Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018	Dec. 30, 2018
Acquired finite-lived intangible assets:
Gross Value	$ 128.7		$ 108.9
Accumulated Amortization	(101.2)		(99.7)
Net Value	27.5		9.2
Total intangible assets: Gross Value	135.6		115.8
Total intangible assets: Net Value	34.4		16.1
Aggregate amortization expense for finite-lived intangible assets	1.5	$ 1.7
Trade names
Acquired finite-lived intangible assets:
Indefinite-lived trade names	6.9		6.9
Customer relationships
Acquired finite-lived intangible assets:
Gross Value	63.8		52.6
Accumulated Amortization	(51.1)		(50.6)
Net Value	12.7		2.0
Contracts and backlog
Acquired finite-lived intangible assets:
Gross Value	32.1		29.9
Accumulated Amortization	(26.7)		(26.4)
Net Value	5.4		3.5
Developed technology and technical know-how
Acquired finite-lived intangible assets:
Gross Value	25.0		25.0
Accumulated Amortization	(22.0)		(21.3)
Net Value	3.0		3.7
Trade names
Acquired finite-lived intangible assets:
Gross Value	1.8		1.4
Accumulated Amortization	(1.4)		(1.4)
Net Value	0.4		0.0
In-process research and development
Acquired finite-lived intangible assets:
Gross Value	6.0		0.0
Accumulated Amortization	0.0		0.0
Net Value	$ 6.0		$ 0.0