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 Oct. 01, 2016	$ 1,609,803	$ 6,120,509		$ (456,796)	$ 65,381	$ (4,119,291)
Common Stock, Shares, Issued at Oct. 01, 2016			98,141
Treasury Stock, Shares at Oct. 01, 2016				(25,110)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances under stock plans			3,531
Issuances Under Stock Plans, Value	27,129	27,129
Stock-based compensation	37,450	37,450
Repurchases of Treasury Stock, Shares				(4,898)
Repurchases of Treasury Stock, Value	(176,944)			$ (176,944)
Other comprehensive income (loss)	11,413				11,413
Net income (loss)	138,833					138,833
Common Stock, Shares, Issued at Sep. 30, 2017			101,672
Treasury Stock, Shares at Sep. 30, 2017				(30,008)
Balance at Sep. 30, 2017	1,647,684	6,185,088		$ (633,740)	76,794	(3,980,458)
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)
Net income (loss)	$ (95,533)					(95,533)
Common Stock, Shares, Issued at Sep. 29, 2018	103,128		103,128
Treasury Stock, Shares at Sep. 29, 2018	(35,351)			(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]
Cumulative effect of new accounting pronouncement	43,269					43,269
Issuances under stock plans			2,423
Issuances Under Stock Plans, Value	13,539	13,539
Stock-based compensation	30,844	30,844
Adjustments to Additional Paid in Capital, Other		138
Repurchases of Treasury Stock, Shares				(480)
Repurchases of Treasury Stock, Value				$ (12,752)
Treasury Stock, Value, Acquired, Cost Method and Adjustments to APIC	12,614
Other comprehensive income (loss)	(31,685)				(31,685)
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]
Cumulative effect of new accounting pronouncement	$ 28,130					$ 28,130