Share-Based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of share based compensation expense allocated to cost of sales	20.00%
Percentage of share based compensation expense allocated to selling, general and administrative expense	80.00%
Share based compensation expense	$ 19,676	$ 16,036	$ 10,906
Aggregate intrinsic value of stock options and cash-based stock appreciation rights, outstanding	96,100	69,300	10,100
Aggregate intrinsic value of stock options and cash-based stock appreciation rights, exercised	96,100	69,300	10,100
Total intrinsic value of stock options and cash-based stock appreciation rights, exercised	$ 14,700	12,300	4,500
Unrecognized compensation cost, weighted-average period of recognition, years	3 years
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance share grant, period	12 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance share grant, period	36 months
Stock Options and Cash-Based Stock Appreciation Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 6,605	$ 5,611	$ 4,309
Weighted-average fair values of stock options granted under the stock option Plan	$ 14.23	$ 8.88	$ 7.35
Share based compensation, estimated forfeiture percentage	17.60%
Share based compensation expense attributable to non-vested shares	$ 13,900
Restricted Share Awards and Cash-Based Restricted Share Unit Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 7,850	$ 6,799	$ 4,401
Share based compensation, estimated forfeiture percentage	10.20%
Share based compensation, vesting period years	3 years
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense attributable to non-vested shares	$ 9,700
Unrecognized compensation cost, weighted-average period of recognition, years	2 years
Total fair value of restricted stock grant	$ 7,500	7,800	6,300
Total fair value of restricted stock vested	17,000	6,200	5,500
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense attributable to non-vested shares	$ 4,700
Unrecognized compensation cost, weighted-average period of recognition, years	1 year
Total fair value of restricted stock grant	$ 3,800	5,300	2,400
Total fair value of restricted stock vested	3,600	5,900	1,500
Liability Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 4,400	$ 4,300	$ 1,200
Omnibus Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock authorized for issuance under the Plan	4,900,000
Shares available to be issued under the Plan	955,000

Percentage of share based compensation expense allocated to cost of sales.

No definition available.

Name:	iivi_PercentageOfShareBasedCompensationExpenseAllocatedToCostOfSales
Namespace Prefix:	iivi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of share based compensation expense allocated to selling general and administrative expense.

+ References

No definition available.

+ Details

Name:	iivi_PercentageOfShareBasedCompensationExpenseAllocatedToSellingGeneralAndAdministrativeExpense
Namespace Prefix:	iivi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Performance share grant period.

+ References

No definition available.

+ Details

Name:	iivi_PerformanceShareGrantPeriod
Namespace Prefix:	iivi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Total fair value of restricted and performance shares granted during the period.

+ References

No definition available.

+ Details

Name:	iivi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantInPeriodFairValue
Namespace Prefix:	iivi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award estimated forfeiture rate.

+ References

No definition available.

+ Details

Name:	iivi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEstimatedForfeitureRate
Namespace Prefix:	iivi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=iivi_StockOptionAndStockAppreciationRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=iivi_RestrictedStockAwardsAndRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=iivi_LiabilityAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=iivi_OmnibusEquityIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: