Consolidated Statement of Stockholder's Equity Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Net Investment Hedging	Net Investment Hedging Accumulated Other Comprehensive Loss	Cash Flow Hedging	Cash Flow Hedging Accumulated Other Comprehensive Loss
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-09	$ 125		$ 681	$ (556)
Beginning balance (in shares) at Sep. 30, 2017		115,333
Beginning balance at Sep. 30, 2017	885,436	$ 1,153	1,609,030	(650,840)	$ (73,907)
Common stock issued for employee stock-based awards	0	$ 14	(14)
Common stock issued for employee stock-based awards (in shares)		1,377
Shares surrendered by employees to pay taxes related to stock-based awards	(33,942)	$ (5)	(33,937)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(530)
Common stock issued for employee stock purchase plan (in shares)		158
Common stock issued for employee stock purchase plan	7,472	$ 1	7,471
Compensation expense from stock-based awards	35,357		35,357
Net income (loss)	21,799			21,799
Unrealized gain (loss) on hedging instruments, net of tax	(875)							$ (875)	$ (875)
Foreign currency translation adjustment	12,769				12,769
Unrealized loss on available-for-sale securities, net of tax	(446)				(446)
Change in pension benefits, net of tax	29				29
Ending balance (in shares) at Mar. 31, 2018		116,338
Ending balance at Mar. 31, 2018	927,724	$ 1,163	1,618,588	(629,597)	(62,430)
Beginning balance (in shares) at Dec. 30, 2017		116,126
Beginning balance at Dec. 30, 2017	889,099	$ 1,161	1,594,546	(637,519)	(69,089)
Common stock issued for employee stock-based awards	0	$ 1	(1)
Common stock issued for employee stock-based awards (in shares)		60
Shares surrendered by employees to pay taxes related to stock-based awards	(454)	$ 0	(454)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(6)
Common stock issued for employee stock purchase plan (in shares)		158
Common stock issued for employee stock purchase plan	7,472	$ 1	7,471
Compensation expense from stock-based awards	17,026		17,026
Net income (loss)	7,922			7,922
Unrealized gain (loss) on hedging instruments, net of tax	(535)							(535)	(535)
Foreign currency translation adjustment	7,540				7,540
Unrealized loss on available-for-sale securities, net of tax	(267)				(267)
Change in pension benefits, net of tax	(79)				(79)
Ending balance (in shares) at Mar. 31, 2018		116,338
Ending balance at Mar. 31, 2018	927,724	$ 1,163	1,618,588	(629,597)	(62,430)
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-16	72,261			72,261
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2014-09	$ 367,378			367,378
Beginning balance (in shares) at Sep. 30, 2018	117,981	117,981
Beginning balance at Sep. 30, 2018	$ 874,589	$ 1,180	1,558,403	(599,409)	(85,585)
Common stock issued for employee stock-based awards	0	$ 11	(11)
Common stock issued for employee stock-based awards (in shares)		1,108
Shares surrendered by employees to pay taxes related to stock-based awards	(34,491)	$ (4)	(34,487)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(388)
Common stock issued for employee stock purchase plan (in shares)		122
Common stock issued for employee stock purchase plan	8,798	$ 1	8,797
Common stock issued	(140)		(140)
Compensation expense from stock-based awards	56,374		56,374
Net income (loss)	(22,528)			(22,528)
Repurchases of common stock (in shares)		(725)
Repurchases of common stock	(64,994)	$ (7)	(64,987)
Unrealized gain (loss) on hedging instruments, net of tax	277					$ 662	$ 662	$ (385)	$ (385)
Foreign currency translation adjustment	(11,602)				(11,602)
Unrealized loss on available-for-sale securities, net of tax	302				302
Change in pension benefits, net of tax	$ 1,484				1,484
Ending balance (in shares) at Mar. 30, 2019	118,098	118,098
Ending balance at Mar. 30, 2019	$ 1,247,708	$ 1,181	1,523,949	(182,298)	(95,124)
Beginning balance (in shares) at Dec. 29, 2018		118,657
Beginning balance at Dec. 29, 2018	1,321,169	$ 1,187	1,553,875	(138,785)	(95,108)
Common stock issued for employee stock-based awards	0	$ 0	0
Common stock issued for employee stock-based awards (in shares)		52
Shares surrendered by employees to pay taxes related to stock-based awards	(703)	$ 0	(703)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(8)
Common stock issued for employee stock purchase plan (in shares)		122
Common stock issued for employee stock purchase plan	8,798	$ 1	8,797
Compensation expense from stock-based awards	26,967		26,967
Net income (loss)	(43,513)			(43,513)
Repurchases of common stock (in shares)		(725)
Repurchases of common stock	(64,994)	$ (7)	(64,987)
Unrealized gain (loss) on hedging instruments, net of tax	(2,955)					$ 2,955	$ 2,955
Foreign currency translation adjustment	(4,033)				(4,033)
Unrealized loss on available-for-sale securities, net of tax	289				289
Change in pension benefits, net of tax	$ 773				773
Ending balance (in shares) at Mar. 30, 2019	118,098	118,098
Ending balance at Mar. 30, 2019	$ 1,247,708	$ 1,181	$ 1,523,949	$ (182,298)	$ (95,124)