Acquisitions (Unaudited Pro-Forma Consolidated Results Of Operations) (Details) (Aegis Lightwave, Inc. [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Aegis Lightwave, Inc. [Member]
Business Acquisition [Line Items]
Net revenues	$ 126,757	$ 129,644	$ 265,130	$ 256,648
Net earnings attributable to II-VI Incorporated	$ 13,287	$ 21,125	$ 31,866	$ 41,120
Basic earnings per share	$ 0.21	$ 0.34	$ 0.51	$ 0.65
Diluted earnings per share	$ 0.21	$ 0.33	$ 0.50	$ 0.63