Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock And Additional Paid in Capital	Number of Common Shares	Treasury Stock	Accumulated Other Comprehensive Income	Accumulated Deficit
Balance at Sep. 30, 2017	$ 1,647,684	$ 6,185,088		$ (633,740)	$ 76,794	$ (3,980,458)
Common Stock, Shares, Issued at Sep. 30, 2017			101,672
Treasury Stock, Shares at Sep. 30, 2017				(30,008)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances under stock plans			1,456
Issuances Under Stock Plans, Value	4,407	4,407
Stock-based compensation	33,493	33,493
Repurchases of Treasury Stock, Shares				(5,343)
Repurchases of Treasury Stock, Value	(157,626)			$ (157,626)
Other comprehensive income (loss)	(2,850)				(2,850)
Cumulative effect of new accounting pronouncement						43,269
Net income (loss)	(95,533)					(95,533)
Common Stock, Shares, Issued at Sep. 29, 2018			103,128
Treasury Stock, Shares at Sep. 29, 2018				(35,351)
Balance at Sep. 29, 2018	1,472,844	6,222,988		$ (791,366)	73,944	(4,032,722)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances under stock plans			2,423
Issuances Under Stock Plans, Value	13,539	13,539
Stock-based compensation	30,844	30,844
Repurchases of treasury stock		138
Repurchases of Treasury Stock, Shares				(480)
Repurchases of Treasury Stock, Value				$ (12,752)
Repurchases of treasury stock	12,614
Other comprehensive income (loss)	(31,685)				(31,685)
Cumulative effect of new accounting pronouncement						28,130
Net income (loss)	$ 141,515					141,515
Common Stock, Shares, Issued at Sep. 28, 2019	105,551		105,551
Treasury Stock, Shares at Sep. 28, 2019	(35,831)			(35,831)
Balance at Sep. 28, 2019	$ 1,642,573	6,267,509		$ (804,118)	42,259	(3,863,077)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances under stock plans			2,078
Issuances Under Stock Plans, Value	7,793	7,793
Stock-based compensation	26,235	26,235
Repurchases of Treasury Stock, Shares				(6,799)
Repurchases of Treasury Stock, Value	(179,025)			$ (179,025)
Other comprehensive income (loss)	(7,373)				(7,373)
Net income (loss)	$ 139,713					139,713
Common Stock, Shares, Issued at Oct. 03, 2020	107,629		107,629
Treasury Stock, Shares at Oct. 03, 2020	(42,630)			(42,630)
Balance at Oct. 03, 2020	$ 1,629,916	$ 6,301,537		$ (983,143)	$ 34,886	$ (3,723,364)