Goodwill and Intangible Assets - Finite Lived Assets (Details) - USD ($) $ in Thousands	9 Months Ended
Jun. 28, 2020	Sep. 29, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 101,486	$ 96,722
Accumulated Amortization	(89,029)	(80,282)
Estimated amortization expense
2020	2,561
2021	5,960
2022	2,229
2023	1,506
2024	201
Total	$ 12,457
Client relations
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Life (in Years)	2 years 9 months 18 days
Gross Amount	$ 58,909	56,779
Accumulated Amortization	$ (52,479)	(50,455)
Backlog
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Life (in Years)	8 months 12 days
Gross Amount	$ 34,770	32,229
Accumulated Amortization	$ (30,668)	(24,968)
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Life (in Years)	1 year 10 months 24 days
Gross Amount	$ 7,807	7,714
Accumulated Amortization	$ (5,882)	$ (4,859)

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Publisher FASB
-Name Accounting Standards Codification
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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in remainder of current fiscal year.

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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