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Fair Value - Changes in Assets and Liabilities with Inputs Classified within Level 3 of Fair Value (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 29, 2017
Contingent consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 585	$ 1,679	$ 848
Net Realized/Unrealized Losses (Gains) Included in Earnings	65	(394)	(180)
Purchases and Issuances	0	0	1,701
Sales and Settlements	(650)	(700)	(1,050)
Ending balance	0	585	1,679
Warrant liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	13,129	40,775	38,253
Net Realized/Unrealized Losses (Gains) Included in Earnings	(765)	(27,646)	(2,522)
Purchases and Issuances	0	0	0
Sales and Settlements	0	0	0
Ending balance	$ 12,364	$ 13,129	$ 40,775

X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis liability purchases and issuances.

+ References

No definition available.

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X

- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis liability sales and settlement.

+ References

No definition available.

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X

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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X

- Definition

Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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X

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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