Balance Sheet Details (Details) $ in Thousands, € in Millions	3 Months Ended
	Dec. 29, 2018 EUR (€)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)	Sep. 29, 2018 USD ($)
Inventory, Net [Abstract]
Purchased parts and assemblies		$ 148,940		$ 137,566
Work-in-process		178,947		186,240
Finished goods		165,269		162,935
Total inventories		493,156		486,741
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid and refundable income taxes		39,165		37,884
Other taxes receivable		15,267		16,930
Prepaid expenses and other assets		29,709		30,266
Total prepaid expenses and other assets		84,141		85,080
Other Assets, Noncurrent Disclosure [Abstract]
Assets related to deferred compensation arrangements		35,465		37,370
Deferred tax assets		65,043		64,858
Other assets (1)		12,448		9,521
Total other assets		112,956		111,749
Payments to acquire investments	€ 3.0	3,400
Other Liabilities, Current [Abstract]
Accrued payroll and benefits		45,044		55,704
Deferred revenue		21,997		30,613
Warranty reserve		40,489		40,220
Accrued expenses and other		35,725		36,859
Customer deposits		18,146		19,933
Total other current liabilities		161,401		183,329
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Beginning balance		40,220	$ 36,149
Additions related to current period sales		17,081	14,140
Warranty costs incurred in the current period		(16,376)	(12,404)
Accruals resulting from acquisitions		21	0
Adjustments to accruals related to foreign exchange and other		(457)	(76)
Ending balance		40,489	$ 37,809
Other Liabilities, Noncurrent [Abstract]
Long-term taxes payable		35,709		36,336
Deferred compensation		39,021		40,895
Defined benefit plan liabilities		37,873		37,528
Deferred tax liabilities		21,615		26,339
Deferred revenue		5,509		5,091
Asset retirement obligations liability		4,551		4,529
Other long-term liabilities		1,235		1,238
Total other long-term liabilities		$ 145,513		$ 151,956