Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net sales	$ 3,568,186	$ 3,540,226	$ 3,218,626
Cost of goods sold	3,184,590	3,184,786	2,891,536
Gross profit	383,596	355,440	327,090
Selling, general and administrative expenses	265,178	240,115	210,985
Depreciation expense	9,444	7,326	5,356
Intangible amortization expense	15,524	9,828	6,641
Change in fair value of contingent consideration	5,211	1,294	2,667
Operating income	88,239	96,877	101,441
Interest expense	3,215	2,124	1,797
Interest income	(5,329)	(3,448)	(2,638)
Other (income) expense, net	(11,142)	2,191	2,376
Income before income taxes	101,495	96,010	99,906
Provision for income taxes	32,249	32,391	34,487
Net income	$ 69,246	$ 63,619	$ 65,419
Per share data:
Net income per common share, basic (in dollars per share)	$ 2.74	$ 2.40	$ 2.29
Weighted-average shares outstanding, basic (in shares)	25,318	26,472	28,558
Net income per common share, diluted (in dollars per share)	$ 2.71	$ 2.38	$ 2.27
Weighted-average shares outstanding, diluted (in shares)	25,515	26,687	28,799