Leases Schedule of Impacts of Adoption of New Accounting Pronouncement (Details) - USD ($) $ in Thousands	Jul. 04, 2020	Sep. 29, 2019	Sep. 28, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other	$ 32,836	$ 31,804	$ 31,974
Operating lease right-of-use assets	71,885	75,790	0
Property, plant and equipment, net	380,056	382,391	384,224
Deferred income taxes	14,089	14,086	13,654
Other assets	34,707	34,521	64,714
Other accrued liabilities	105,290	114,400	106,461
Long-term debt and finance lease obligations, net of current portion	188,626	187,071	187,278
Long-term operating lease liabilities	38,077	37,371	0
Retained earnings	$ 1,257,374	1,177,600	$ 1,178,677
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other		(170)
Operating lease right-of-use assets		75,790
Property, plant and equipment, net		(1,833)
Deferred income taxes		432
Other assets		(30,193)
Other accrued liabilities		7,939
Long-term debt and finance lease obligations, net of current portion		(207)
Long-term operating lease liabilities		37,371
Retained earnings		$ (1,077)