Document and Entity Information	3 Months Ended
	Sep. 30, 2012	Nov. 01, 2012
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Trading Symbol	IIVI
Entity Registrant Name	II-VI INC
Entity Central Index Key	0000820318
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		62,701,396