Business Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Total net sales	$ 819,982	$ 764,281	$ 751,526
Depreciation and amortization	26,943	26,001	23,452
Adjusted EBITDA - Total segments	162,378	149,744	143,383
Reconciliation of income before income taxes to Adjusted EBITDA
Income before income taxes	88,070	80,543	76,761
Interest expense, net	11,910	14,906	16,592
Depreciation and amortization	26,943	26,001	23,452
Acquisition-related cost of goods sold	1,671		2,566
Acquisition-related accrued compensation	1,152	1,680	1,680
Acquisition-related transaction costs	400	1,274	618
Acquisition-related other, net		(972)
Pension settlement cost	0	1,702	0
Gain on insurance settlement	0	7,500	0
Foreign currency (gains) losses, net	(1,054)	(113)	(7,609)
Loss on extinguishment of debt		2,598
Adjusted EBITDA - Total segments	162,378	149,744	143,383
Identifiable assets	671,679	623,397
Operating Segments
Segment Reporting Information [Line Items]
Total net sales	819,982	764,281	751,526
Depreciation and amortization	24,847	23,403	20,423
Adjusted EBITDA - Total segments	162,378	149,744	143,383
Reconciliation of income before income taxes to Adjusted EBITDA
Income before income taxes	88,070	80,543	76,761
Interest expense, net	11,910	14,906	16,592
Depreciation and amortization	24,847	23,403	20,423
Acquisition-related cost of goods sold	1,671	0	2,566
Acquisition-related accrued compensation	1,152	1,680	1,680
Acquisition-related transaction costs	400	1,274	618
Acquisition-related other, net	(468)	(972)	0
Stock-based compensation	334	0	0
Pension settlement cost	0	1,702	0
Gain on insurance settlement	0	(7,500)	0
Foreign currency (gains) losses, net	(1,054)	(113)	(7,609)
Loss on extinguishment of debt	0	2,598	0
Adjusted EBITDA - Total segments	162,378	149,744	143,383
Identifiable assets	549,523	521,386
Operating Segments | Animal Health
Segment Reporting Information [Line Items]
Total net sales	531,727	497,745	486,140
Depreciation and amortization	21,447	20,132	17,149
Adjusted EBITDA - Total segments	141,914	130,261	127,442
Reconciliation of income before income taxes to Adjusted EBITDA
Depreciation and amortization	21,447	20,132	17,149
Adjusted EBITDA - Total segments	141,914	130,261	127,442
Identifiable assets	455,704	442,521
Operating Segments | Mineral Nutrition
Segment Reporting Information [Line Items]
Total net sales	234,922	218,298	216,685
Depreciation and amortization	2,371	2,332	2,467
Adjusted EBITDA - Total segments	18,583	17,426	14,971
Reconciliation of income before income taxes to Adjusted EBITDA
Depreciation and amortization	2,371	2,332	2,467
Adjusted EBITDA - Total segments	18,583	17,426	14,971
Identifiable assets	69,779	55,184
Operating Segments | Performance Products
Segment Reporting Information [Line Items]
Total net sales	53,333	48,238	48,701
Depreciation and amortization	1,029	939	807
Adjusted EBITDA - Total segments	1,881	2,057	970
Reconciliation of income before income taxes to Adjusted EBITDA
Depreciation and amortization	1,029	939	807
Adjusted EBITDA - Total segments	1,881	2,057	970
Identifiable assets	24,040	23,681
Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization	2,096	2,598	3,029
Reconciliation of income before income taxes to Adjusted EBITDA
Depreciation and amortization	2,096	2,598	3,029
Corporate costs	33,420	29,625	$ 29,323
Identifiable assets	$ 122,156	$ 102,011