Significant Customers - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2022	Dec. 26, 2021	Dec. 27, 2020
Revenue, Major Customer [Line Items]
Revenue	$ 898.3	$ 811.5	$ 747.7
KGS
Revenue, Major Customer [Line Items]
Revenue	676.6	579.6
U.S. Government | KGS
Revenue, Major Customer [Line Items]
Revenue	$ 623.7	$ 571.1	$ 546.4
U.S. Government | KGS | Revenue benchmark | Customer concentration risk
Revenue, Major Customer [Line Items]
Sales to the U.S. Government, percentage of total revenue (percent)	69.00%	70.00%	73.00%