Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Basic Earnings Per Share
Net income	$ 271,860	$ 249,209
Less: Income allocated to participating securities	167	166
Income available to common shareholders	$ 271,693	$ 249,043
Basic weighted average shares outstanding (in shares)	141,820	133,682
Net income per share - Basic (USD per share)	$ 1.92	$ 1.86
Diluted Earnings Per Share
Income available to common shareholders	$ 271,693	$ 249,043
Effect of dilutive shares	0	0
Income available to common shareholders	$ 271,693	$ 249,043
Basic weighted average shares outstanding (in shares)	141,820	133,682
Dilutive shares (in shares)	117	7
Diluted weighted average shares outstanding (in shares)	141,937	133,689
Net income per share - Diluted (USD per share)	$ 1.91	$ 1.86