Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Dec. 31, 2017 USD ($)
Goodwill [Line Items]
Balance-beginning of period	$ 250,342
Goodwill acquired	19,670
Foreign currency translation	1,801
Balance-end of period	272,209
IPI
Goodwill [Line Items]
Balance-beginning of period	17,503
Goodwill adjustment for prior year acquisition - IPI	396
II-VI Laser Solutions
Goodwill [Line Items]
Balance-beginning of period	84,180
Goodwill acquired	19,670
Foreign currency translation	691
Balance-end of period	104,541
II-VI Photonics
Goodwill [Line Items]
Balance-beginning of period	113,272
Foreign currency translation	1,110
Balance-end of period	114,778
II-VI Photonics | IPI
Goodwill [Line Items]
Balance-beginning of period	17,500
Goodwill adjustment for prior year acquisition - IPI	396
II- VI Performance Products
Goodwill [Line Items]
Balance-beginning of period	52,890
Balance-end of period	$ 52,890