Financial Information of Company's Operation by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	$ 189,207	$ 185,833
Operating income	21,728	19,396
Interest expense	(649)	(1,204)
Other income (expense), net	1,057	(1,682)
Income taxes	(4,922)	(4,208)
Net earnings	17,214	12,302
Depreciation and amortization	13,305	13,561
Segment assets	1,034,026		$ 1,058,164
Expenditures for property, plant and equipment	9,424	21,530
Investment	12,178		11,914
Goodwill	194,594		195,894
Eliminations
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Inter-segment revenues	(9,956)	(10,112)
II-VI Laser Solutions
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	43,580		43,578
II-VI Laser Solutions | Operating Segments
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	71,583	72,824
Inter-segment revenues	4,530	5,064
Operating income	12,175	12,923
Depreciation and amortization	3,704	3,533
Segment assets	331,159
Expenditures for property, plant and equipment	5,880	16,066
Goodwill	43,580
II-VI Photonics
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	98,124		99,426
II-VI Photonics | Operating Segments
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	71,895	63,613
Inter-segment revenues	3,031	2,820
Operating income	6,284	2,072
Depreciation and amortization	5,093	5,522
Segment assets	429,764
Expenditures for property, plant and equipment	2,152	2,893
Goodwill	98,124
II- VI Performance Products
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Goodwill	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	45,729	49,396
Inter-segment revenues	2,395	2,228
Operating income	3,269	4,401
Depreciation and amortization	4,508	4,506
Segment assets	273,103
Expenditures for property, plant and equipment	1,392	$ 2,571
Investment	12,178
Goodwill	$ 52,890