Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net sales	$ 3,540,226	$ 3,218,626	$ 2,913,634
Cost of goods sold	3,184,786	2,891,536	2,612,535
Gross profit	355,440	327,090	301,099
Selling, general and administrative expenses	257,269	222,982	192,492
Legal recovery on impairment charges	0	0	(15,490)
Change in fair value of contingent consideration	1,294	2,667	2,311
Operating income	96,877	101,441	121,786
Interest expense	2,124	1,797	731
Interest income	(3,448)	(2,638)	(2,364)
Other (income) expense, net	2,191	2,376	312
Income before income taxes	96,010	99,906	123,107
Provision for income taxes	32,391	34,487	41,318
Net income	$ 63,619	$ 65,419	$ 81,789
Per share data:
Net income per common share, basic (in dollars per share)	$ 2.40	$ 2.29	$ 2.89
Weighted-average shares outstanding, basic (in shares)	26,472	28,558	28,337
Net income per common share, diluted (in dollars per share)	$ 2.38	$ 2.27	$ 2.86
Weighted-average shares outstanding, diluted (in shares)	26,687	28,799	28,602