Earnings Per Share (Details) (USD $) In Thousands, except Share data	3 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Earnings Per Share [Abstract]
Net earnings attributable to II-VI Incorporated	$ 18,579	$ 18,367
Weighted average shares	62,698,000	61,808,000
Basic earnings attributable to II-VI Incorporated per common share	$ 0.30	$ 0.30
Dilutive effect of common stock equivalents	1,367,000	1,480,000
Diluted weighted average common shares	64,065,000	63,288,000
Diluted earnings attributable to II-VI Incorporated per common share	$ 0.29	$ 0.29
Weighted average shares issuable upon the exercise of stock options excluded from the dilutive share calculation	124,000	524,000