Fair Value Measurements and Disclosures about Fair Value of Financial Instruments - Reconciliation of derivative assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Fair Value Measurements and Disclosures about Fair Value of Financial Instruments
Beginning balance	$ 362	$ 268	$ (238)
Unrealized gains (losses) recognized in earnings, net of settlements	986	$ (268)	1,586
Ending balance	$ 1,348		$ 1,348