Income Taxes - Components of Federal and State Income Taxes Included in the Consolidated Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Current Income Taxes —
Federal	$ 6,453	$ 11,744	$ 0
State	5,899	1,386	12,214
Deferred Income Taxes —
Federal	894	106,801	137,025
State	(3,504)	44,602	(32,610)
Total Income Taxes	$ 9,742	$ 164,533	$ 116,629