Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings available to stockholders	$ 153,440	$ 340,280	$ 54,872
Diluted weighted average common shares outstanding (in shares)	170,674,570	167,994,042	148,913,560
Basic weighted average common shares outstanding (in shares)	170,674,570	167,994,042	148,913,560
Basic earnings per common share (in dollars per share)	$ 0.90	$ 2.03	$ 0.37
Diluted earnings per common share (in dollars per share)	$ 0.90	$ 2.03	$ 0.37
Weighted average number of shares outstanding, factor adjustment percentage			1.03%