Income Taxes (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2016	Dec. 28, 2019	Dec. 29, 2018	Sep. 30, 2019
Income Tax Disclosure [Line Items]
Effective income tax rate		(86.00%)	(3.00%)
Income before income taxes		$ 19,031	$ 20,423
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%
Reduction of valuation allowance		$ 21,000	$ 1,800
Unrecognized tax benefits		12,500		$ 11,500
Income tax provision upon recognition of unrecognized tax benefit		12,500
Unrecognized tax benefits that would impact valuation allowance		6,100
Potentail reduction in unrecognized tax benefits and accrued interest over next 12 months		(500)
Korea
Income Tax Disclosure [Line Items]
Income tax examination, estimate of possible loss	$ 12,000
Additional Exposure [Member] | KOREA, REPUBLIC OF
Income Tax Disclosure [Line Items]
Income tax examination, estimate of possible loss		$ 13,000