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, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net earnings	$ 47,906	$ 68,313	$ 78,211	$ 109,883
Denominator:
Basic	62,550	63,278	62,825	63,043
Dilutive effect of stock options and restricted stock	2,068	2,376	2,038	2,231
Diluted shares outstanding	64,618	65,654	64,863	65,274
Income per common share:
Basic earnings per share	$ 0.77	$ 1.08	$ 1.24	$ 1.74
Diluted earnings per share	$ 0.74	$ 1.04	$ 1.21	$ 1.68