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	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net earnings	$ 97,556	$ 35,511	$ 187,600	$ 65,117
Denominator:
Basic shares outstanding	60,427	59,807	60,223	59,736
Dilutive effect of stock options and restricted stock	1,938	1,420	1,883	1,347
Diluted shares outstanding	62,365	61,227	62,106	61,083
Income per common share:
Basic earnings per share	$ 1.61	$ 0.59	$ 3.12	$ 1.09
Diluted earnings per share	$ 1.56	$ 0.58	$ 3.02	$ 1.07