Computation of Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Line Items]
Net earnings attributable to II-VI Incorporated	$ 9,694	$ 12,718
Weighted average shares	62,379	62,786
Basic earnings attributable to II-VI Incorporated per common share	$ 0.16	$ 0.20
Net earnings attributable to II-VI Incorporated	$ 9,694	$ 12,718
Weighted average shares	62,379	62,786
Dilutive effect of common stock equivalents	1,568	1,413
Diluted weighted average common shares	63,947	64,199
Diluted earnings attributable to II-VI Incorporated per common share	$ 0.15	$ 0.20