Summary of Significant Accounting Policies - Concentration Risk (Details)	3 Months Ended
	Dec. 31, 2022 item customer	Dec. 31, 2021 customer item
Concentration of Credit Risk
Number of banks for maintenance of cash balances	2
Revenues Net | Customer Concentration Risk
Concentrations
Number of major customers | customer	3	2
Revenues Net | Customer Concentration Risk | Pilatus Aircraft Ltd ("Pilatus")
Concentrations
Concentration of risk (as a percent)	38.00%	24.00%
Revenues Net | Customer Concentration Risk | Textron Aviation, Inc
Concentrations
Concentration of risk (as a percent)	11.00%
Revenues Net | Customer Concentration Risk | Air Transport Services Group
Concentrations
Concentration of risk (as a percent)	13.00%	25.00%
Inventory | Supplier Concentration Risk
Concentrations
Number of major suppliers	2
Supplier Concentration Risk
Concentrations
Number of major suppliers		2