Segment and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2017
Segment financial information
Net sales	$ 827,665	$ 679,304	$ 2,175,553	$ 1,912,275
Operating income for reportable segments	56,444	45,668	154,996	126,943
Assets used in business	2,272,323	1,346,691	2,272,323	1,346,691	$ 1,387,595
Depreciation and amortization of property	4,713	3,877	12,721	11,364
Capital expenditures	6,439	5,077	17,898	11,787
Operating Segments [Member]
Segment financial information
Operating income for reportable segments	74,813	48,310	165,655	117,571
Service Center Based Distribution [Member]
Segment financial information
Net sales	601,214	573,797	1,725,734	1,617,361
Operating income for reportable segments	48,229	36,042	111,957	85,125
Assets used in business	1,202,593	1,184,150	1,202,593	1,184,150
Depreciation and amortization of property	3,885	3,650	11,356	10,674
Capital expenditures	4,385	3,228	14,754	9,496
Fluid Power & Flow Control Segment [Member]
Segment financial information
Net sales	226,451	105,507	449,819	294,914
Operating income for reportable segments	26,584	12,268	53,698	32,446
Assets used in business	1,069,730	162,541	1,069,730	162,541
Depreciation and amortization of property	828	227	1,365	690
Capital expenditures	$ 2,054	$ 1,849	$ 3,144	$ 2,291