Fair Value of Plan Assets of Defined Benefit Pension and Post-Retirement Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	$ 457,575
Company contribution	10,100	$ 10,100	$ 10,700
Ending balance	469,801	457,575
Pension Plan | Plan Assets - Fair Value
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	457,575	425,781
Currency translation adjustment	(5,297)	8,170
Realized and unrealized gain (loss) on plan assets	33,859	41,566
Plan participants contributions	553	318
Company contribution	9,086	6,681
Other adjustments	474	0
Expenses paid	(1,269)	(1,254)
Benefits paid	(25,180)	(23,687)
Ending balance	469,801	457,575	425,781
Other Postretirement Benefit Plan | Plan Assets - Fair Value
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	0	0
Currency translation adjustment	0	0
Realized and unrealized gain (loss) on plan assets	0	0
Plan participants contributions	0	0
Company contribution	586	550
Other adjustments	0	0
Expenses paid	0	0
Benefits paid	(586)	(550)
Ending balance	$ 0	$ 0	$ 0