Condensed Consolidated Income Statements (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Net sales	$ 747,716	$ 782,684	$ 1,481,320	$ 1,552,943
Cost of goods sold	673,365	702,845	1,332,930	1,394,013
Gross profit	74,351	79,839	148,390	158,930
Selling, general and administrative expenses	49,393	48,474	96,454	95,043
Change in fair value of contingent consideration	533	(722)	1,296	172
Operating income	24,425	32,087	50,640	63,715
Interest expense	130	749	254	1,236
Interest income	(532)	(1,002)	(1,166)	(1,452)
Other (income) expense, net	53	(374)	39	3,157
Income before income taxes	24,774	32,714	51,513	60,774
Provision for income taxes	8,417	11,347	17,514	21,028
Net income	$ 16,357	$ 21,367	$ 33,999	$ 39,746
Per share data:
Weighted-average shares outstanding, basic	27,713	27,244	27,665	27,191
Net income per common share, basic (in dollars per share)	$ 0.59	$ 0.78	$ 1.23	$ 1.46
Weighted-average shares outstanding, diluted	27,958	27,674	27,928	27,604
Net income per common share, diluted (in dollars per share)	$ 0.59	$ 0.77	$ 1.22	$ 1.44