Income Taxes - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Income Tax Examination [Line Items]
Effective tax rate on income before income taxes	6.50%	10.40%
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	21.00%		24.50%
Decreased South Korean income taxes by tax exemption		$ 2,400
Income taxes payable/receivable	$ (25,024)	(119,929)	$ 474
Valuation allowance, deferred tax asset, increase (decrease), amount	(16,200)
Valuation allowance	(57,707)	(41,491)
Operating loss carryforwards and tax credits	83,447	71,890
Unrecognized tax benefits, including interest and penalties	42,400
Unrecognized tax benefits that would impact effective tax rate	31,200
Deferred tax assets, tax deferred expense, reserves and accruals, reserves	17,300
Deferred tax assets, tax deferred expense	8,700
Unrecognized tax benefits	39,507	58,111	65,882	$ 47,566
Unrecognized tax benefits, income tax penalties and interest accrued	2,900	5,800
Tax benefit credit to APIC when recognized
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, foreign	53,400
SINGAPORE
Income Tax Examination [Line Items]
Income taxes payable/receivable	2,600	$ 3,900	$ 2,500
Foreign Tax Authority
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits	114,200
Deferred tax assets, operating loss carryforwards, not subject to expiration	87,100
Deferred tax assets, operating loss carryforwards, subject to expiration	27,200
Operating loss carryforwards, valuation allowance	104,300
Federal Government
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits	11,800
State Government
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits	30,700
Internal Revenue Service (IRS) | Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research	38,700
CALIFORNIA
Income Tax Examination [Line Items]
Tax credit carryforward, valuation allowance	28,800
CALIFORNIA | Not Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research	34,000
Other states besides California
Income Tax Examination [Line Items]
Tax credit carryforward, valuation allowance	1,900
Other states besides California | Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research	3,600
Domestic Tax Authority [Member] | Tax Year 2014 and Year 2016
Income Tax Examination [Line Items]
Unrecognized tax benefits	$ 1,600
South Korea
Income Tax Examination [Line Items]
The benefits of the tax holiday on net income per diluted share		$ 0.10
SINGAPORE
Income Tax Examination [Line Items]
The benefits of the tax holiday on net income per diluted share	$ 0.11	$ 0.16	$ 0.10