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, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Net sales	$ 485,513	$ 468,793	$ 893,852	$ 876,689
Net earnings	42,446	38,751	69,814	67,168
Basic earnings per share	$ 0.62	$ 0.56	$ 1.02	$ 0.97
Diluted earnings per share	$ 0.61	$ 0.55	$ 1.00	$ 0.95
Business Acquisition, Acquiree - Duarte Business [Member]
Pro forma
Net sales	485,513	498,168	924,252	930,182
Net earnings	$ 45,673	$ 36,108	$ 74,235	$ 60,686
Basic earnings per share	$ 0.66	$ 0.52	$ 1.08	$ 0.88
Diluted earnings per share	$ 0.65	$ 0.51	$ 1.06	$ 0.86