Business Acquisitions (Schedule of Unaudited Pro Forma Results) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Business Combinations
Net sales	$ 482,467	$ 485,513	$ 911,509	$ 893,852
Net earnings	44,798	42,446	68,181	69,814
Basic earnings per share	$ 0.67	$ 0.62	$ 1.01	$ 1.02
Diluted earnings per share	$ 0.66	$ 0.61	$ 1.00	$ 1.00
Pro forma
Net sales	482,467	485,513	911,509	924,252
Net earnings	$ 45,138	$ 45,532	$ 68,770	$ 73,970
Basic earnings per share	$ 0.68	$ 0.66	$ 1.02	$ 1.08
Diluted earnings per share	$ 0.66	$ 0.65	$ 1.00	$ 1.06