Goodwill and Intangible Assets - Narrative (Details) - USD ($)		3 Months Ended			9 Months Ended
	Jul. 01, 2019	Jun. 28, 2020	Sep. 29, 2019	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Goodwill [Line Items]
Impairment of goodwill	$ 0
Goodwill		$ 958,162,000	$ 924,820,000		$ 958,162,000
Assets		2,289,309,000	2,147,408,000		2,289,309,000
Amortization expense		2,600,000		$ 2,400,000	$ 9,000,000.0	$ 8,600,000
Income approach, discounted cash flow method
Goodwill [Line Items]
Weighted rate used in fair value of goodwill (as a percent)					70.00%
Market approach
Goodwill [Line Items]
Weighted rate used in fair value of goodwill (as a percent)					30.00%
RFS
Goodwill [Line Items]
Impairment of goodwill			7,800,000
Estimated fair values that exceeded their carrying values, percent (less than)	30.00%
Goodwill		48,000,000	48,800,000		$ 48,000,000
Assets			61,000,000
ASP
Goodwill [Line Items]
Estimated fair values that exceeded their carrying values, percent (less than)	30.00%
Goodwill		109,000,000			109,000,000
GSG
Goodwill [Line Items]
Gross amounts of goodwill		492,200,000	459,500,000		492,200,000
Accumulated impairment		17,700,000	17,700,000		17,700,000
Goodwill		474,464,000	441,802,000		474,464,000
CIG
Goodwill [Line Items]
Gross amounts of goodwill		589,400,000	588,700,000		589,400,000
Accumulated impairment		105,700,000	105,700,000		105,700,000
Goodwill		$ 483,698,000	$ 483,018,000		$ 483,698,000