Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Dec. 25, 2022	May 23, 2022	Dec. 27, 2021	Dec. 26, 2021	Jun. 15, 2020
Business Acquisition [Line Items]
Goodwill	$ 558.2			$ 493.9
CPI ASC Signal Division, Inc.
Business Acquisition [Line Items]
Accounts receivable					$ 5.7
Unbilled receivables					0.9
Inventoried costs					10.4
Other current assets					1.8
Property and equipment					10.0
Intangible assets					4.3
Goodwill					10.8
Total identifiable net assets acquired					43.9
Total identifiable net liabilities assumed					(11.0)
Net assets acquired, excluding cash					$ 32.9
Cosmic Advanced Engineering Solutions, Inc.
Business Acquisition [Line Items]
Accounts receivable		$ 2.9	$ 3.8
Unbilled receivables		11.1	4.1
Inventoried costs		0.5
Other current assets		0.2	0.1
Property and equipment		22.8	1.3
Other assets		0.2
Intangible assets		10.8	8.5
Goodwill		34.3	29.2
Total identifiable net assets acquired		48.5	17.8
Total identifiable net liabilities assumed		(3.4)	(9.1)
Net assets acquired, excluding cash		$ 79.4	$ 37.9