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, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Numerator:
Net earnings	$ 108,949	$ 97,556	$ 196,040	$ 187,600
Denominator:
Basic shares outstanding	59,432	60,427	59,323	60,223
Dilutive effect of stock options; restricted and performance stock	1,912	1,938	1,935	1,883
Diluted shares outstanding	61,344	62,365	61,258	62,106
Income per common share:
Basic earnings per share	$ 1.83	$ 1.61	$ 3.3	$ 3.12
Diluted earnings per share	$ 1.78	$ 1.56	$ 3.2	$ 3.02