Income Tax Expense (Benefit) from Continuing Operations (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 28, 2018	[1]	Jun. 29, 2018	[1]	Mar. 30, 2018	[1]	Dec. 29, 2017	[1]	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Sep. 28, 2018		Sep. 29, 2017	Sep. 30, 2016
Current
U.S. Federal													$ 46,421		$ 2,914	$ 13,848
State													(120)		146	(852)
Foreign													43,868		38,179	30,409
Current Income Tax Expense (Benefit), Total													90,169		41,239	43,405
Deferred
U.S. Federal													4,750		2,744	(6,893)
State													348		(157)	2,060
Foreign													(11,440)		(10,801)	(16,715)
Deferred income tax expense (benefit)													(6,342)		(8,214)	(21,548)
Income tax expense	$ 16,865		$ 11,094		$ 2,079		$ 53,789		$ 9,705	$ 10,703	$ 13,080	$ (463)	$ 83,827	[1]	$ 33,025	$ 21,857

[1] Includes the impact of the Act mainly in the first and fourth quarter of fiscal 2018.