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Goodwill and Intangible Assets - Narrative (Details) - USD ($) |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | ---
Jul. 03, 2017 | Jul. 01, 2018 | Jul. 01, 2018 | Oct. 01, 2017
Goodwill [Line Items] |  |  |  |
Goodwill written off related to sale of divested business |  | $ 12,200,000 | $ 12,160,000 |
Impairment of goodwill | $ 0 |  |  |
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% |
GSG |  |  |  |
Goodwill [Line Items] |  |  |  |
Goodwill written off related to sale of divested business |  |  | $ 0 |
Gross amounts of goodwill |  | 406,600,000 | 406,600,000 | $ 379,500,000
Accumulated impairment |  | 17,700,000 | 17,700,000 | 17,700,000
CIG |  |  |  |
Goodwill [Line Items] |  |  |  |
Goodwill written off related to sale of divested business |  |  | 12,160,000 |
Gross amounts of goodwill |  | 504,800,000 | 504,800,000 | 477,000,000
Accumulated impairment |  | $ 97,900,000 | $ 97,900,000 | $ 97,900,000

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