Earnings Per Share (Reconciliation of Net Earnings to Net Earnings Per Share Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net earnings	$ 171,698	$ 208,649	$ 240,395
Denominator:
Basic shares outstanding	61,517	63,287	62,267
Dilutive effect of stock options and restricted stock units	1,737	2,268	1,942
Diluted shares outstanding	63,254	65,555	64,209
Income per common share:
Basic earnings per share	$ 2.79	$ 3.30	$ 3.86
Diluted earnings per share	$ 2.71	$ 3.18	$ 3.74