Schedule II - Valuation and Qualifying Accounts - Schedule of Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Allowance for losses on accounts receivable (deducted from the asset to which it relates)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 885	$ 980	$ 2,368
Additions charged to costs and expenses	1,189	380	566
Additions charged to other accounts	0	0	0
Deductions	(537)	(475)	(1,954)
Balance at end of period	1,537	885	980
Valuation allowance on deferred income tax assets (deducted from the asset to which it relates)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	28,369	61,668	41,002
Additions charged to costs and expenses	2,213	1,107	20,678
Additions charged to other accounts	0	0	0
Deductions	(1,412)	(34,406)	(12)
Balance at end of period	$ 29,170	$ 28,369	$ 61,668