The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment
Impairment recognized	$ 0	$ 0	$ 0
Buildings and improvements
Property, Plant and Equipment
Estimated economic useful lives	40 years
Machinery and equipment \| Minimum
Property, Plant and Equipment
Estimated economic useful lives	5 years
Machinery and equipment \| Maximum
Property, Plant and Equipment
Estimated economic useful lives	14 years
Land improvements
Property, Plant and Equipment
Estimated economic useful lives	20 years