Reportable Segments - Summary of Segment Data (Detail) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Dec. 25, 2020
Revenues:
Revenues	$ 515.2	$ 515.2	$ 344.8	$ 344.8	$ 932.8	$ 665.7	$ 665.7
Gross profit:
Total segment gross profit	99.9	99.9	73.9	73.9	186.8	139.6	139.6
Operating profit:
Consolidated income from operations	31.9	31.9	30.8	30.8	72.3	53.4	53.4
ASSETS
Total segment assets	1,846.7	1,846.7	1,102.5	1,102.5	1,846.7	1,102.5	1,102.5	$ 1,102.5
Product [Member]
Revenues:
Revenues		442.5		277.9	788.1	537.3
Gross profit:
Total segment gross profit		74.6		48.6	136.6	93.3
Operating profit:
Consolidated income from operations		24.0		24.3	58.2	44.6
ASSETS
Total segment assets	1,597.1	1,597.1	868.4	868.4	1,597.1	868.4	868.4
Services [Member]
Revenues:
Revenues		72.7		66.9	144.7	128.4
Gross profit:
Total segment gross profit		25.3		25.3	50.2	46.3
Operating profit:
Consolidated income from operations		7.9		6.5	14.1	8.8
ASSETS
Total segment assets	$ 249.6	$ 249.6	$ 234.1	$ 234.1	$ 249.6	$ 234.1	$ 234.1