Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Quarterly Financial Data [Line Items]
Net revenues	$ 187,921	$ 173,555	$ 171,765	$ 150,020	$ 154,030	$ 143,940	$ 125,107	$ 127,998	$ 683,261	$ 551,075	$ 516,403
Cost of goods sold	125,600	118,865	118,371	93,709	99,134	92,986	77,839	77,599	456,545	347,558	315,056
Internal research and development	11,322	12,099	11,355	7,747	5,697	5,781	5,626	5,585	42,523	22,689	21,410
Selling, general and administrative	36,295	33,848	32,471	35,093	29,803	27,004	26,174	26,356	137,707	109,337	98,415
Interest expense	1,415	1,412	1,169	483	452	449	223	36	4,479	1,160	212
Other expense (income), net	(868)	(1,694)	(1,125)	53	(442)	(1,401)	(4,551)	(761)	(3,634)	(7,155)	(7,168)
Earnings Before Income Taxes	14,157	9,025	9,524	12,935	19,386	19,121	19,796	19,183	45,641	77,486	88,478
Income taxes	1,502	494	2,086	3,243	4,922	2,861	6,721	4,262	7,325	18,766	17,760
Earnings from continuing operations	12,655	8,531	7,438	9,692	14,464	16,260	13,075	14,921	38,316	58,720	70,718
Earnings (loss) from discontinued operation			131	2	(4,226)	(166)	(608)	(1,789)	133	(6,789)	(9,443)
Net earnings					10,238	16,094	12,467	13,132	38,449	51,931	61,275
Net Earnings Attributable to Noncontrolling Interest					212	225	267	414
Net Earnings Attributable to II-VI Incorporated	$ 12,655	$ 8,531	$ 7,569	$ 9,694	$ 10,026	$ 15,869	$ 12,200	$ 12,718	$ 38,449	$ 50,813	$ 60,306
Net Earnings Attributable to II-VI Incorporated: Basic earnings per share:
Continuing operations	$ 0.21	$ 0.14	$ 0.12	$ 0.16	$ 0.23	$ 0.26	$ 0.20	$ 0.23	$ 0.62	$ 0.92	$ 1.10
Discontinued operation				$ 0.00	$ (0.07)	$ 0.00	$ (0.01)	$ (0.03)		$ (0.11)	$ (0.15)
Consolidated	$ 0.21	$ 0.14	$ 0.12	$ 0.16	$ 0.16	$ 0.26	$ 0.19	$ 0.20	$ 0.62	$ 0.81	$ 0.96
Net Earnings Attributable to II-VI Incorporated: Diluted earnings per share:
Continuing operations	$ 0.20	$ 0.13	$ 0.12	$ 0.15	$ 0.22	$ 0.25	$ 0.20	$ 0.23	$ 0.60	$ 0.90	$ 1.08
Discontinued operation				$ 0.00	$ (0.07)	$ 0.00	$ (0.01)	$ (0.03)		$ (0.11)	$ (0.15)
Consolidated	$ 0.20	$ 0.13	$ 0.12	$ 0.15	$ 0.16	$ 0.25	$ 0.19	$ 0.20	$ 0.60	$ 0.80	$ 0.94