Property, Plant, and Equipment Property, Plant and Equipment (Secured Financing Agreements) (Details) - Equipment Financings - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Property, plant and equipment gross [Member]
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	$ 93,772	$ 71,403
Property, plant and equipment gross [Member] | Machinery and equipment
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	71,012	63,305
Property, plant and equipment gross [Member] | Construction in process
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	22,760	8,098
Property, plant and equipment net [Member]
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	78,716	60,718
Property, plant and equipment net [Member] | Machinery and equipment
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	55,956	52,620
Property, plant and equipment net [Member] | Construction in process
Debt Instrument [Line Items]
Pledged Assets, Not Separately Reported, Other	$ 22,760	$ 8,098