Revenue from Contracts with Customers - Summary of Disaggregated Revenue by Revenue Market and Product (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Revenue	$ 314,433	$ 261,503
II-VI Laser Solutions
Disaggregation Of Revenue [Line Items]
Revenue	106,175
II-VI Photonics
Disaggregation Of Revenue [Line Items]
Revenue	135,156
II- VI Performance Products
Disaggregation Of Revenue [Line Items]
Revenue	73,102
Commercial | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	278,232
Commercial | Services
Disaggregation Of Revenue [Line Items]
Revenue	5,786
Commercial | II-VI Laser Solutions | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	102,870
Commercial | II-VI Laser Solutions | Services
Disaggregation Of Revenue [Line Items]
Revenue	890
Commercial | II-VI Photonics | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	133,365
Commercial | II-VI Photonics | Services
Disaggregation Of Revenue [Line Items]
Revenue	1,791
Commercial | II- VI Performance Products | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	41,997
Commercial | II- VI Performance Products | Services
Disaggregation Of Revenue [Line Items]
Revenue	3,105
U.S. Government | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	27,180
U.S. Government | Services
Disaggregation Of Revenue [Line Items]
Revenue	3,235
U.S. Government | II-VI Laser Solutions | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	2,415
U.S. Government | II- VI Performance Products | Direct Ship Parts
Disaggregation Of Revenue [Line Items]
Revenue	24,765
U.S. Government | II- VI Performance Products | Services
Disaggregation Of Revenue [Line Items]
Revenue	$ 3,235