Commitments and Contingencies - Narrative (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2020 USD ($) press	Sep. 30, 2019 USD ($)	Jul. 31, 2020 press
Loss Contingencies [Line Items]
Impairment charges offset by insurance proceeds		$ 1,107
Quality Aluminum Forge, LLC Manufacturing Facility Fire
Loss Contingencies [Line Items]
Number of presses brought into service | press			2
Number of presses on site in production | press	6
Number of presses on site | press	8
Proceeds recognized	$ 8,974
Insurance proceeds recorded	7,427	11,986
Cash proceeds	10,927	8,486
Business interruption	1,219	1,168
Quality Aluminum Forge, LLC Manufacturing Facility Fire | Buildings
Loss Contingencies [Line Items]
Capital expenditures (equipment)	$ 713	2,878
Quality Aluminum Forge, LLC Manufacturing Facility Fire | Damage from Fire, Explosion or Other Hazard
Loss Contingencies [Line Items]
Number of additional presses to be restored | press	2
Number of presses damaged | press	6
Class Action Suit in Superior Court of California, Orange County - Wage-and-hour law violations
Loss Contingencies [Line Items]
Estimated loss on class action lawsuit	$ 65	$ 250