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
	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net earnings	$ 53,373	$ 49,120
Denominator:
Basic shares outstanding	61,991	61,818
Dilutive effect of stock options and restricted stock	2,682	2,241
Diluted shares outstanding	64,673	64,059
Income per common share:
Basic earnings per share	$ 0.86	$ 0.79
Diluted earnings per share	$ 0.83	$ 0.77