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Goodwill and Intangible Assets - Narrative (Details) - USD ($) |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jul. 02, 2018 | Sep. 30, 2018 | Oct. 01, 2017 | Sep. 30, 2018 | Oct. 01, 2017 | Oct. 02, 2016
Goodwill [Line Items] |  |  |  |  |  |
Impairment of goodwill | $ 0 | $ 0 | $ 0 |  |  |
Percentage of excess of fair value over carrying value (more than) |  | 30.00% |  | 30.00% |  |
Foreign currency translation adjustments |  |  |  | $ 900,000 | $ 100,000 |
Amortization expense for intangible assets |  |  |  | 18,200,000 | 22,800,000 | $ 22,100,000
GSG |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Gross amounts of goodwill |  | $ 407,400,000 | 379,500,000 | 407,400,000 | 379,500,000 |
Accumulated impairment |  | 17,700,000 | 17,700,000 | 17,700,000 | 17,700,000 |
CIG |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Gross amounts of goodwill |  | 507,000,000 | 477,000,000 | 507,000,000 | 477,000,000 |
Accumulated impairment |  | $ 97,900,000 | $ 97,900,000 | $ 97,900,000 | $ 97,900,000 |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274 + Details
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- Definition Amount of foreign currency translation gain (loss) which increases (decreases) assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References No definition available. + Details
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- Definition Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
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