Financial Information of Company's Operation by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2015
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	$ 205,105	$ 182,709	$ 585,746	$ 545,278
Operating income	19,390	17,659	62,899	53,586
Interest expense	(769)	(844)	(2,015)	(3,086)
Other income (expense), net	(1,257)	(1,534)	794	6,079
Income taxes	(2,426)	(773)	(10,535)	(7,673)
Net earnings	14,938	14,508	51,143	48,906
Depreciation and amortization	14,661	12,610	41,785	39,242
Segment assets	1,222,395		1,222,395		$ 1,058,164
Expenditures for property, plant and equipment	13,587	8,554	32,743	40,163
Investment	12,567		12,567		11,914
Goodwill	239,337		239,337		195,894
Eliminations
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Inter-segment revenues	(11,125)	(9,800)	(30,240)	(31,090)
II-VI Laser Solutions
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	88,820		88,820		43,578
II-VI Laser Solutions | Operating Segments
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	73,778	73,289	215,552	213,743
Inter-segment revenues	5,962	5,023	15,342	15,585
Operating income	5,395	14,058	28,820	39,207
Depreciation and amortization	4,192	3,233	11,587	10,134
Segment assets	502,754		502,754
Expenditures for property, plant and equipment	7,156	2,994	16,511	22,432
Goodwill	88,820		88,820
II-VI Photonics
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	97,627		97,627		99,426
II-VI Photonics | Operating Segments
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	80,603	64,303	226,762	188,794
Inter-segment revenues	3,363	2,853	9,160	9,473
Operating income	9,543	608	23,282	3,093
Depreciation and amortization	4,888	5,124	14,961	15,875
Segment assets	449,511		449,511
Expenditures for property, plant and equipment	4,160	2,098	10,783	8,067
Goodwill	97,627		97,627
II- VI Performance Products
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	52,890		52,890		$ 52,890
II- VI Performance Products | Operating Segments
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	50,724	45,117	143,432	142,741
Inter-segment revenues	1,800	1,924	5,738	6,032
Operating income	4,452	2,993	10,797	11,286
Depreciation and amortization	5,581	4,253	15,237	13,233
Segment assets	270,130		270,130
Expenditures for property, plant and equipment	2,271	$ 3,462	5,449	$ 9,664
Investment	12,567		12,567
Goodwill	$ 52,890		$ 52,890