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, 2018	Dec. 31, 2017
Numerator:
Net earnings	$ 49,120	$ 18,260
Denominator:
Basic shares outstanding	61,818	61,246
Dilutive effect of stock options and restricted stock	2,241	2,463
Diluted shares outstanding	64,059	63,709
Income per common share:
Basic earnings per share	$ 0.79	$ 0.30
Diluted earnings per share	$ 0.77	$ 0.29