Gains on Sale of Trademarks, net - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Feb. 29, 2016	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks				$ 1,268	$ 875
Badgley Mischka Intellectual Property / MJCLK Apparel License
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Proceeds from sale of rights			$ 13,800
Badgley Mischka Intellectual Property / MJCLK Apparel License | UNITED STATES
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks			$ 11,600
Interest in Badgley Mischka Canada trademark
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks	$ 400				375	[1]
Proceeds from sale of interest	400
Badgley Mischka Intellectual Property and Related Assets
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks				300
Badgley Mischka Intellectual Property and Related Assets
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks				12,300
Sharper Image intellectual property and related assets
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Proceeds from sale of rights		$ 100,000
Net gains (losses) on sale of trademarks		28,100		29,600
Held in escrow for sale of property		$ 1,800
Interest in Sharper Image Canada trademark
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks	500				$ 500	[2]
Proceeds from sale of interest	$ 500
Sharper Image intellectual property and related assets
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Net gains (losses) on sale of trademarks				$ 1,000

[1] In February 2016, the Company sold its rights to the Badgley Mischka intellectual property and related assets to Titan Industries, Inc. in partnership with the founders, Mark Badgley and James Mischka, and the apparel license MJCLK LLC for $13.8 million in cash. The Company recognized a gain of $11.6 million as a result of this transaction. The $11.6 million gain represented the sale of the Badgley Mischka intellectual property and related assets within the United States, Greater China, Israel and Latin America territories. The Badgley Mischka intellectual property and related assets within other foreign territories is owned by certain of the Company’s joint venture entities and required the Company to negotiate and finalize the sale of the intellectual property with its respective joint venture partners. In September 2017, the Company sold its interest in certain Badgley Mischka trademarks for shoes and handbags in Canada for $0.4 million in cash. The Company recognized a gain of $0.4 million as a result of this transaction. Additionally, in FY 2018, the Company recognized an additional combined gain of approximately $0.3 million upon final execution of the agreement for the sale of the Badgley Mischka intellectual property and related assets which were previously owned by the Iconix Southeast Asia, Iconix Europe and Iconix MENA joint ventures resulting in an aggregate gain on the sale of the brand of $12.3 million.

[2] In December 2016, the Company sold the rights to the Sharper Image intellectual property and related assets to 360 Holdings, Inc. for $100.0 million in cash (of which $1.8 million is being held in escrow for the sale of the Sharper Image intellectual property in the Company’s international joint ventures). The Company recognized a gain of $28.1 million as a result of this transaction. The Sharper Image intellectual property and related assets within other foreign territories is owned by certain of the Company’s joint venture entities and required the Company to negotiate and finalize the sale of the intellectual property with its respective joint venture partners. In September 2017, the Company sold its interest in the Sharper Image trademark in Canada for $0.5 million in cash. The Company recognized a gain of $0.5 million as a result of this transaction. In FY 2018, the Company recognized an additional combined gain of approximately $1.0 million upon final execution of the agreement for the sale of the Sharper Image intellectual property and related assets which were previously owned by the Iconix Southeast Asia, Iconix Europe, Iconix MENA, and Iconix Australia joint ventures resulting in an aggregate gain on the sale of the brand of $29.6 million.