Restructuring Charges - Additional Information (Detail) - USD ($)	3 Months Ended						9 Months Ended	12 Months Ended
	Mar. 28, 2020	Jun. 29, 2019	Dec. 29, 2018	Jun. 30, 2018	Dec. 30, 2017	Jul. 01, 2017	Jun. 30, 2018	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Restructuring Cost and Reserve [Line Items]
Severance charges								$ 13,400,000	$ 4,000,000.0	$ 9,000,000.0
Incremental cost								5,000,000.0		1,300,000
Expected future severance charges								1,700,000
Divestiture charges	$ 1,900,000
Tepnel [Member]
Restructuring Cost and Reserve [Line Items]
Divestiture charges	1,300,000
Cynosure
Restructuring Cost and Reserve [Line Items]
Incremental cost	2,600,000
Divestiture charges	$ 2,000,000.0
Bedford
Restructuring Cost and Reserve [Line Items]
Facility closure costs		$ 1,400,000		$ 1,600,000	$ 3,500,000	$ 1,300,000
Remaining lease balance								$ 3,800,000
International
Restructuring Cost and Reserve [Line Items]
Severance charges									$ 1,000,000.0	$ 2,200,000
Lyberty Way [Member]
Restructuring Cost and Reserve [Line Items]
Facility closure costs							$ 900,000
Property closure cost payment			$ 600,000
Property closure benefit			$ 300,000