Reportable Segments - Summary of Segment Data (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020	Dec. 25, 2020
Revenues:
Total segment revenues	$ 417.6	$ 320.9
Gross profit:
Total segment gross profit	86.9	65.7
Operating profit:
Consolidated income from operations	40.4	22.6
ASSETS
Total segment assets	1,190.6		$ 1,102.5
Product [Member]
Revenues:
Total segment revenues	345.6	259.4
Gross profit:
Total segment gross profit	62.0	44.7
Operating profit:
Consolidated income from operations	34.2	20.3
ASSETS
Total segment assets	950.0		868.4
Services [Member]
Revenues:
Total segment revenues	72.0	61.5
Gross profit:
Total segment gross profit	24.9	21.0
Operating profit:
Consolidated income from operations	6.2	$ 2.3
ASSETS
Total segment assets	$ 240.6		$ 234.1