Segment Information (Financial Information by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Sales	$ 845,990	$ 729,873	$ 2,567,652	$ 2,298,111
Depreciation and amortization	7,305	8,358	22,184	25,417
Change in fair value of contingent consideration	0	0	0	516
Operating income (loss)	32,917	19,436	94,742	38,201
Capital expenditures	(682)	(829)	(3,326)	(2,283)
Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	693	719	2,131	2,308
Operating income (loss)	0	(832)	(30)	(11,442)
Reportable Geographical Components | United States and Canada
Segment Reporting Information [Line Items]
Sales	766,035	666,773	2,312,250	2,081,377
Reportable Geographical Components | International
Segment Reporting Information [Line Items]
Sales	81,461	64,153	259,693	228,784
Geography Eliminations
Segment Reporting Information [Line Items]
Sales	(1,506)	(1,053)	(4,291)	(12,050)
Specialty Technology Solutions
Segment Reporting Information [Line Items]
Sales	503,072	436,462	1,501,702	1,300,488
Capital expenditures	(62)	(532)	(496)	(1,097)
Specialty Technology Solutions | Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	2,874	3,200	8,741	10,054
Operating income (loss)	20,623	8,713	51,278	17,558
Modern Communications & Cloud
Segment Reporting Information [Line Items]
Sales	342,918	293,411	1,065,950	997,623
Change in fair value of contingent consideration	0	0	0	516
Capital expenditures	(620)	(297)	(2,830)	(1,186)
Modern Communications & Cloud | Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	3,738	4,439	11,312	13,055
Operating income (loss)	$ 12,294	$ 11,555	$ 43,494	$ 32,085