Earnings Per Share - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings available to stockholders	$ 376,646	$ 273,785	$ 258,631
Basic weighted average shares outstanding (in shares)	265,999,341	201,260,961	170,324,784
Diluted weighted average shares outstanding (in shares)	265,999,341	201,260,961	170,324,784
Basic earnings per share (in dollars per share)	$ 1.42	$ 1.36	$ 1.52
Diluted earnings per share (in dollars per share)	$ 1.42	$ 1.36	$ 1.52