Goodwill and Other Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Acquired finite-lived intangible assets:
Gross Value	$ 108.9	$ 108.9
Accumulated Amortization	(99.7)	(93.8)
Total	9.2	15.1
Total intangible assets, Gross Value	115.8	115.8
Total intangible assets, Net Value	16.1	22.0
Aggregate amortization expense for finite-live intangible assets	5.9	10.4	$ 10.5
Trade names
Acquired finite-lived intangible assets:
Indefinite-lived trade names	6.9	6.9
Customer relationships
Acquired finite-lived intangible assets:
Gross Value	52.6	52.6
Accumulated Amortization	(50.6)	(49.1)
Total	2.0	3.5
Contracts and backlog
Acquired finite-lived intangible assets:
Gross Value	29.9	29.9
Accumulated Amortization	(26.4)	(24.8)
Total	3.5	5.1
Developed technology and technical know-how
Acquired finite-lived intangible assets:
Gross Value	25.0	25.0
Accumulated Amortization	(21.3)	(18.6)
Total	3.7	6.4
Trade names
Acquired finite-lived intangible assets:
Gross Value	1.4	1.4
Accumulated Amortization	(1.4)	(1.3)
Total	$ 0.0	$ 0.1