Number of warrants or rights exercisable.

No definition available.

Name:	icon_ClassOfWarrantOrRightExercisableNumber
Namespace Prefix:	icon_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Employment termination date.

+ References

No definition available.

+ Details

Name:	icon_EmploymentTerminationDate
Namespace Prefix:	icon_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award, equity instruments other than options, cancelled in period.

+ References

No definition available.

+ Details

Name:	icon_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod
Namespace Prefix:	icon_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award equity instruments other than options cash award aggragate amount.

+ References

No definition available.

+ Details

Name:	icon_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCashAwardAggragateAmount
Namespace Prefix:	icon_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award, equity instruments other than options, exercises in period.

+ References

No definition available.

+ Details

Name:	icon_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisesInPeriod
Namespace Prefix:	icon_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based compensation arrangement by share-based payment award vesting number of shares issuable.

+ References

No definition available.

+ Details

Name:	icon_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingNumberOfSharesIssuable
Namespace Prefix:	icon_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation expense reversal.

+ References

No definition available.

+ Details

Name:	icon_ShareBasedCompensationExpenseReversal
Namespace Prefix:	icon_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Sharebased compensation arrangement by sharebased payment award, percentage of each award form to total award.

+ References

No definition available.

+ Details

Name:	icon_SharebasedCompensationArrangementBySharebasedPaymentAwardPercentage
Namespace Prefix:	icon_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights exercisable.

+ References

No definition available.

+ Details

Name:	icon_WarrantsExercisableWeightedAverageExercisePrice
Namespace Prefix:	icon_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- 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

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

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

+ Details

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

- 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

+ 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

Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

+ References

No definition available.

+ Details

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

- 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

+ Details

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

- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

+ References

+ Details

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

- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

+ References

+ Details

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

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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

- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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

- Definition

Date the equity-based award expires, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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

+ Details

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

- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

+ Details

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

- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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

+ Details

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

- Definition

Number of options outstanding, including both vested and non-vested options.

+ 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

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

+ Details

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

- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares for which recognition of compensation cost was accelerated.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

+ References

No definition available.

+ Details

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

- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of share options (or share units) exercised during the current period.

+ 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 (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_TitleOfIndividualAxis=icon_FormerChiefExecutiveOfficerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
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:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_PlanNameAxis=icon_LongTermIncentiveCompensation2016PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_TitleOfIndividualAxis=icon_OtherThanMrHaughMember
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_AwardTypeAxis=icon_TimeBasedAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=icon_LongTermIncentiveCompensation2017PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=icon_LongTermIncentiveCompensation2018PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Stockholders' Equity - Additional Information (Detail) - USD ($)										3 Months Ended			9 Months Ended
	Jun. 15, 2018	Mar. 15, 2018	Oct. 31, 2017	Mar. 07, 2017	Mar. 31, 2016	Feb. 23, 2016	Jan. 07, 2016	Aug. 15, 2012	Aug. 13, 2009	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	May 07, 2018	Apr. 26, 2018	Apr. 25, 2018	Dec. 31, 2017	Nov. 04, 2016
Class Of Stock [Line Items]
Common stock, par value										$ 0.001			$ 0.001					$ 0.001
Common stock, shares authorized										260,000,000			260,000,000			260,000,000	150,000,000	260,000,000
Stock options outstanding										20,000			20,000
Stock options exercisable										20,000			20,000
Stock options outstanding, weighted average exercise price										$ 12.29			$ 12.29
Stock options exercisable, weighted average exercise price										$ 12.29			$ 12.29
Stock options, canceled													0
Stock options, exercised													0
Stock options, expired/forfeited													0
Mr. Haugh
Class Of Stock [Line Items]
Employment resigned date	Jun. 15, 2018
Warrant
Class Of Stock [Line Items]
Share based compensation awards granted in period													0	0
Warrants outstanding										20,000			20,000
Warrants exercisable										20,000			20,000
Warrants outstanding, weighted average exercise price										$ 6.64			$ 6.64
Warrants exercisable, weighted average exercise price										$ 6.64			$ 6.64
Warrants, canceled													0
Warrants, exercised													0
Share based compensation awards forfeited in period													0
Weighted average contractual term of awards outstanding and exercisable													3 days
Stock Options
Class Of Stock [Line Items]
Compensation expense (benefit) related to stock grants													$ 0	$ 0
Stock options granted													0	0
Weighted average contractual term of awards outstanding and exercisable													9 months
Restricted Stock
Class Of Stock [Line Items]
Share based compensation awards granted in period													50,000
Share based compensation awards forfeited in period													116,395
Compensation cost not yet recognized, period for recognition													18 months
Granted													$ 0.75
Restricted Stock \| Maximum
Class Of Stock [Line Items]
Share based compensation awards vesting period													3 years
Retention Stock
Class Of Stock [Line Items]
Compensation expense (benefit) related to stock grants										$ 200,000	$ 200,000		$ 700,000	$ 700,000
Share based compensation awards granted in period							7,500,000
Share based compensation awards vesting period							3 years
Compensation cost not yet recognized, period for recognition													3 months
Share based compensation awards granted in period, value							$ 1,300,000
Grant date fair value of award issued							$ 4.25
Compensation cost not yet recognized										$ 200,000			$ 200,000
Retention Stock \| Mr. Haugh
Class Of Stock [Line Items]
Share-based compensation award, vesting shares Issuable	0
Employment Inducement Award \| Mr. Haugh
Class Of Stock [Line Items]
Grant date fair value of award issued						$ 5.75
2009 Equity Incentive Plan
Class Of Stock [Line Items]
Number of common stock shares authorized under Equity Incentive Plan									3,000,000
Plan expiration date									Aug. 13, 2019
Amended and Restated 2009 Equity Incentive Plan
Class Of Stock [Line Items]
Number of common stock shares authorized under Equity Incentive Plan								7,000,000
Plan expiration date								Aug. 15, 2022
Number of additional common stock shares approved for issuance under Incentive Plan								4,000,000
2016 Omnibus Incentive Plan
Class Of Stock [Line Items]
Number of additional common stock shares approved for issuance under Incentive Plan			1,900,000
Common stock reserved for issuance										3,400,000			3,400,000		1,900,000				2,400,000
Long-Term Incentive Plan \| Restricted Stock
Class Of Stock [Line Items]
Compensation expense (benefit) related to stock grants										$ 200,000	600,000		$ 1,900,000	2,900,000
Long Term Incentive Compensation Plan \| Restricted Stock
Class Of Stock [Line Items]
Compensation cost not yet recognized										$ 700,000			$ 700,000
2016 LTIP
Class Of Stock [Line Items]
Share based compensation awards granted in period												707,028
Share based compensation awards forfeited in period													100,000
Share based compensation awards granted in period, value					$ 5,200,000							$ 5,200,000
Granted					$ 7.31
2016 LTIP \| Maximum
Class Of Stock [Line Items]
Share based compensation awards forfeited in period										100,000
2016 LTIP \| RSUs
Class Of Stock [Line Items]
Share based compensation awards vesting period												3 years
Share based compensation award, description of vesting rights												three equal installments annually
2016 LTIP \| RSUs \| Mr. Haugh
Class Of Stock [Line Items]
Share based compensation awards, form of awards percentage												25.00%
2016 LTIP \| RSUs \| Other Than Mr Haugh
Class Of Stock [Line Items]
Share based compensation awards, form of awards percentage												33.00%
2016 LTIP \| Performance Shares
Class Of Stock [Line Items]
Compensation expense (benefit) related to stock grants										$ 2,100,000	$ 1,700,000		$ 2,800,000	$ 600,000
Compensation cost not yet recognized, period for recognition													3 months
Compensation cost not yet recognized										$ 100,000			$ 100,000
2016 LTIP \| Performance Shares \| Mr. Haugh
Class Of Stock [Line Items]
Share based compensation awards, form of awards percentage												75.00%
Description of award conversion													Subject to his continued employment, one-third of Mr. Haugh’s PSUs were to be converted to time-based awards on December 31, 2016, December 31, 2017 and December 31, 2018, based on the achievement of aggregate adjusted operating income performance targets established by the Compensation Committee
2016 LTIP \| Performance Shares \| Other Than Mr Haugh
Class Of Stock [Line Items]
Share based compensation awards vesting period												3 years
Share based compensation awards, form of awards percentage												67.00%
Share based compensation award, description of vesting rights												based on the achievement of an aggregate adjusted operating income performance target established by the Compensation Committee
2016 LTIP \| Performance Shares \| Maximum
Class Of Stock [Line Items]
Weighted average contractual term of awards outstanding and exercisable													1 year
2016 LTIP \| Time Based Awards \| Mr. Haugh
Class Of Stock [Line Items]
Share based compensation award, description of vesting rights												vest and be settled on December 31, 2018
Share based compensation awards, vested	200,000
Accelerated stock compensation expense for awards	$ 300,000
2016 LTIP \| Time Based Awards \| Mr. Haugh \| December 31, 2018
Class Of Stock [Line Items]
Share based compensation expense reversal	$ 600,000
2017 LTIP
Class Of Stock [Line Items]
Share based compensation awards granted in period				871,011
Share based compensation awards forfeited in period													200,000
Share based compensation awards granted in period, value				$ 6,600,000
Granted				$ 7.52
2017 LTIP \| Maximum
Class Of Stock [Line Items]
Share based compensation awards forfeited in period										100,000
2017 LTIP \| RSUs
Class Of Stock [Line Items]
Share based compensation awards, form of awards percentage				33.00%
Share based compensation award, description of vesting rights				one third annually
2017 LTIP \| Performance Shares
Class Of Stock [Line Items]
Weighted average contractual term of awards outstanding and exercisable													2 years
Share based compensation awards, form of awards percentage				67.00%
Share based compensation award, description of vesting rights				based on performance metrics approved by the Compensation Committee
2018 LTIP
Class Of Stock [Line Items]
Share based compensation awards granted in period		2,241,828
Share based compensation awards forfeited in period													900,000
Share based compensation awards vesting period		15 days
Share based compensation awards granted in period, value		$ 3,100,000
Granted		$ 1.38
Share based compensation award, description of vesting rights		48 equal semi-monthly installments
Share based compensation cash awards, aggregate amount.		$ 3,100,000
2018 LTIP \| Maximum
Class Of Stock [Line Items]
Share based compensation awards forfeited in period										100,000
2018 LTIP \| Performance Shares
Class Of Stock [Line Items]
Weighted average contractual term of awards outstanding and exercisable													3 years
Share based compensation awards, form of awards percentage		50.00%
2018 LTIP \| Cash Grant
Class Of Stock [Line Items]
Share based compensation awards, form of awards percentage		50.00%