Benefit Obligations of Defined Benefit Pension and Post-Retirement Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 15,790	$ 15,108	$ 12,861
Interest cost	17,057	15,553	18,095
Pension Plan | Benefit Obligation
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	509,256	505,298
Currency translation adjustment	(5,735)	9,340
Service cost	15,790	15,108
Interest cost	17,057	15,553
Plan participants contributions	553	318
Actuarial (gain) loss	(16,124)	(11,420)
Other adjustments	(230)	(1,254)
Benefits paid	(25,180)	(23,687)
Ending balance	495,387	509,256	505,298
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	361	385	342
Interest cost	402	335	473
Other Postretirement Benefit Plan | Benefit Obligation
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	13,542	13,236
Currency translation adjustment	(450)	665
Service cost	361	385
Interest cost	402	335
Plan participants contributions	0	0
Actuarial (gain) loss	(349)	(529)
Other adjustments	0	0
Benefits paid	(586)	(550)
Ending balance	$ 12,920	$ 13,542	$ 13,236