Goodwill and Other Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 25, 2022
Acquired finite-lived intangible assets:
Gross Value	$ 188.3	$ 174.3
Accumulated Amortization	(132.8)	(126.0)
Total	55.5	48.3
Total intangible assets, Gross Value	195.2	181.2
Total intangible assets, Net Value	62.4	55.2
Trade names
Acquired finite-lived intangible assets:
Indefinite-lived trade names	6.9	6.9
Customer relationships
Acquired finite-lived intangible assets:
Gross Value	80.9	80.9
Accumulated Amortization	(62.8)	(60.1)
Total	18.1	20.8
Contracts and backlog
Acquired finite-lived intangible assets:
Gross Value	53.1	39.1
Accumulated Amortization	(38.8)	(36.3)
Total	14.3	2.8
Developed technology and technical know-how
Acquired finite-lived intangible assets:
Gross Value	33.7	33.7
Accumulated Amortization	(28.2)	(27.0)
Total	5.5	6.7
Trade names
Acquired finite-lived intangible assets:
Gross Value	3.8	3.8
Accumulated Amortization	(2.7)	(2.3)
Total	1.1	1.5
In-process research and development
Acquired finite-lived intangible assets:
Gross Value	16.8	16.8
Accumulated Amortization	(0.3)	(0.3)
Total	$ 16.5	$ 16.5