Consolidated Entities, Joint Ventures and Investments - Equity Method Investments (Detail) - Iconix China Holdings Limited $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($)
Schedule Of Investments [Line Items]
Value of Investment	$ 25,568
Candies Shanghai Fashion Co., Ltd.
Schedule Of Investments [Line Items]
Brands Placed	Candie’s
Ownership by Iconix China	20.00%
Value of Investment	$ 10,539
Shanghai MuXiang Apparel & Accesory Co. Limited
Schedule Of Investments [Line Items]
Brands Placed	Marc Ecko
Ownership by Iconix China	15.00%
Value of Investment	$ 2,270
Ningbo Material Girl Fashion Co., Ltd
Schedule Of Investments [Line Items]
Brands Placed	Material Girl
Ownership by Iconix China	20.00%
Value of Investment	$ 2,217
Ai Xi Enterprise (Shanghai) Co. Limited
Schedule Of Investments [Line Items]
Brands Placed	Ecko Unltd
Ownership by Iconix China	20.00%
Value of Investment	$ 10,542

Brand placed.

No definition available.

Name:	icon_BrandPlaced
Namespace Prefix:	icon_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

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

- Details

Name:	dei_LegalEntityAxis=icon_IconixChinaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=icon_CandiesShanghaiFashionCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=icon_ShanghaiMuXiangApparelAndAccesoryCoLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=icon_NingboMaterialGirlFashionCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=icon_AiXiEnterpriseShanghaiCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: