Goodwill and Other Intangible Assets - Narrative (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019	Dec. 28, 2019
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 938,500,000		$ 938,500,000		$ 913,800,000
Accumulated impairment losses	0		$ 0
Weighted-average amortization period (in years)			11 years
Aggregate amortization expense	5,800,000	$ 5,500,000	$ 17,200,000	$ 16,300,000
Estimated annual amortization expense for fiscal period 2020	22,700,000		22,700,000
Estimated annual amortization expense for fiscal period 2021	21,300,000		21,300,000
Estimated annual amortization expense for fiscal period 2022	17,700,000		17,700,000
Estimated annual amortization expense for fiscal period 2023	14,500,000		14,500,000
Estimated annual amortization expense for fiscal period 2024	11,200,000		11,200,000
Estimated annual amortization expense for fiscal period 2025	6,800,000		6,800,000
Sigmavision
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	5,600,000		5,600,000
Cognitran Limited
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	14,500,000		$ 14,500,000
Customer relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Weighted-average amortization period (in years)			15 years
Customer relationship contractual term, minimum (in years)			3 years
Customer relationship contractual term, maximum (in years)			5 years
Repair Systems & Information Group
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	628,500,000		$ 628,500,000		$ 615,100,000
Repair Systems & Information Group | Sigmavision
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 5,600,000		5,600,000
Repair Systems & Information Group | Cognitran Limited
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill, purchase accounting adjustments			$ 3,100,000