For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Receivables And Concentration Of Credit Risk (Narrative) (Details) $ in Millions	3 Months Ended
	Dec. 29, 2019 USD ($) customer	Dec. 30, 2018	Sep. 30, 2019 USD ($)	Sep. 30, 2018 customer
Receivables [Line Items]
Allowance for uncollectible receivables \| $	$ 4.8		$ 4.9
Major Customer Three [Member] \| Net Sales And/Or Trade Receivables [Member]
Receivables [Line Items]
Number of major customers accounting for a significant percentage of sales and/or receivables volume \| customer	3			3
Major Customer Three [Member] \| Net Sales And/Or Trade Receivables [Member] \| Minimum [Member]
Receivables [Line Items]
Concentration risk	10.00%			10.00%
Major Customer Three [Member] \| Sales Revenue, Goods, Net [Member]
Receivables [Line Items]
Concentration risk	30.80%	29.90%
Major Customer Three [Member] \| Trade Receivable [Member]
Receivables [Line Items]
Concentration risk	39.30%		29.90%