Business Segment Information - Additional Information (Details) $ in Millions	12 Months Ended
Sep. 30, 2020 USD ($) segment customer	Sep. 30, 2019 USD ($) customer	Sep. 30, 2018 USD ($)
Number of reportable segments \| segment	3
Percentage of Sale of Customer Maximum	10.00%	10.00%
Capitalized Computer Software, Period Increase (Decrease)	$ 9.0	$ 8.4	$ 9.5
Customer concentration \| Sales
Number of customers who exceeded 10% of sales \| customer	1	0
Property, Plant and Equipment
Depreciation	$ 19.5	$ 16.5	$ 15.4

Number of customers who exceeded the benchmark percentage of concentration risk.

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- Definition

Percentage Of Sale Of Customer Maximum

+ References

No definition available.

+ Details

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- Definition

Amount of increase (decrease) in capitalized computer software costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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