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	$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,805
Shares surrendered by employees to pay taxes related to stock-based awards	(44,797)	$ (6)	(44,791)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(658)
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	52,015		52,015
Net income (loss)	38,796			38,796
Repurchases of common stock (in shares)		(1,147)
Repurchases of common stock	(100,000)	$ (11)	(99,989)
Unrealized gain (loss) on hedging instruments, net of tax	3,277							$ 3,277	$ 3,277
Foreign currency translation adjustment	(8,859)				(8,859)
Unrealized loss on available-for-sale securities, net of tax	(379)				(379)
Change in pension benefits, net of tax	1,299				1,299
Ending balance (in shares) at Jun. 30, 2018		115,491
Ending balance at Jun. 30, 2018	834,385	$ 1,155	1,524,399	(612,600)	(78,569)
Beginning balance (in shares) at Mar. 31, 2018		116,338
Beginning balance at Mar. 31, 2018	927,724	$ 1,163	1,618,588	(629,597)	(62,430)
Common stock issued for employee stock-based awards	0	$ 4	(4)
Common stock issued for employee stock-based awards (in shares)		428
Shares surrendered by employees to pay taxes related to stock-based awards	(10,855)	$ (1)	(10,854)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(128)
Compensation expense from stock-based awards	16,658		16,658
Net income (loss)	16,997			16,997
Repurchases of common stock (in shares)		(1,147)
Repurchases of common stock	(100,000)	$ (11)	(99,989)
Unrealized gain (loss) on hedging instruments, net of tax	4,152							4,152	4,152
Foreign currency translation adjustment	(21,628)				(21,628)
Unrealized loss on available-for-sale securities, net of tax	67				67
Change in pension benefits, net of tax	1,270				1,270
Ending balance (in shares) at Jun. 30, 2018		115,491
Ending balance at Jun. 30, 2018	834,385	$ 1,155	1,524,399	(612,600)	(78,569)
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	$ 15	(15)
Common stock issued for employee stock-based awards (in shares)		1,479
Shares surrendered by employees to pay taxes related to stock-based awards	(44,191)	$ (5)	(44,186)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(501)
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	71,608		71,608
Net income (loss)	(37,286)			(37,286)
Repurchases of common stock (in shares)		(3,970)
Repurchases of common stock	(89,995)	$ (40)	(89,955)
Unrealized gain (loss) on hedging instruments, net of tax	(2,367)					$ (1,982)	$ (1,982)	$ (385)	$ (385)
Foreign currency translation adjustment	(7,209)				(7,209)
Unrealized loss on available-for-sale securities, net of tax	477				477
Change in pension benefits, net of tax	$ 1,672				1,672
Ending balance (in shares) at Jun. 29, 2019	115,111	115,111
Ending balance at Jun. 29, 2019	$ 1,215,595	$ 1,151	1,504,512	(197,056)	(93,012)
Beginning balance (in shares) at Mar. 30, 2019		118,098
Beginning balance at Mar. 30, 2019	1,247,708	$ 1,181	1,523,949	(182,298)	(95,124)
Common stock issued for employee stock-based awards	0	$ 4	(4)
Common stock issued for employee stock-based awards (in shares)		371
Shares surrendered by employees to pay taxes related to stock-based awards	(9,700)	$ (1)	(9,699)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(113)
Compensation expense from stock-based awards	15,234		15,234
Net income (loss)	(14,758)			(14,758)
Repurchases of common stock (in shares)		(3,245)
Repurchases of common stock	(25,001)	$ (33)	(24,968)
Unrealized gain (loss) on hedging instruments, net of tax	(2,644)					$ (2,644)	$ (2,644)
Foreign currency translation adjustment	4,393				4,393
Unrealized loss on available-for-sale securities, net of tax	175				175
Change in pension benefits, net of tax	$ 188				188
Ending balance (in shares) at Jun. 29, 2019	115,111	115,111
Ending balance at Jun. 29, 2019	$ 1,215,595	$ 1,151	$ 1,504,512	$ (197,056)	$ (93,012)