Summary of Significant Accounting Policies (Earnings Per Share Basic And Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Accounting Policies [Abstract]
Net Income (Loss)	$ 376,333	$ 245,540	$ 313,081
Weighted average shares outstanding	119,679	118,341	117,194
Dilutive effect of employee stock options, restricted shares and restricted stock units	1,063	993	1,039
Diluted weighted average shares outstanding	120,742	119,334	118,233
Earnings per share-Basic	$ 3.14	$ 2.07	$ 2.67
Earnings per share-Diluted	$ 3.12	$ 2.06	$ 2.65