Schedule of Gains on Sale of Trademarks, net (Detail) - USD ($) $ in Thousands	1 Months Ended						12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Apr. 30, 2016	Jan. 31, 2016	Dec. 31, 2017		Dec. 31, 2016
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Total gains (losses) on sales of trademarks							$ 875		$ 38,104
BBC and Ice Cream brands
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Total gains (losses) on sales of trademarks						$ (600)			(593)	[1]
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]
Total gains (losses) on sales of trademarks				$ 11,800					11,812	[2]
Ed Hardy China Trademark
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Total gains (losses) on sales of trademarks					$ (1,900)				(1,950)	[3]
London Fog Korea trademark
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Total gains (losses) on sales of trademarks				$ (600)					575	[4]
Interest in Badgley Mischka China trademark
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Total gains (losses) on sales of trademarks			$ 100						147	[5]
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]
Total gains (losses) on sales of trademarks		$ 28,100							$ 28,113	[6]
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]
Total gains (losses) on sales of trademarks	$ 400						375	[7]
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]
Total gains (losses) on sales of trademarks	$ 500						$ 500	[8]

[1] In January 2016, the Company sold its interest in the BBC and Ice Cream brands for $3.5 million in cash. The Company recognized a loss of $0.6 million as a result of this transaction.

[2] 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. As a result, in June 2016, the Company recognized an additional gain of approximately $0.2 million upon receipt of cash associated with the sale of the Badgley Mischka intellectual property and related assets which was previously owned by the Iconix Australia joint venture resulting in an aggregate gain on sale of the brand of $11.8 million.

[3] In April 2016, the Company sold its interest in TangLi International, Ltd. (Ed Hardy China) for $11.4 million in cash. The Company recognized a loss of $1.9 million as a result of this transaction.

[4] In June 2016, the Company sold its rights to the London Fog intellectual property in the South Korea territory to NS International Limited for 1.1 billion Korean Won (approximately $1.0 million) in cash. The Company recognized a gain of approximately $0.6 million as a result of this transaction.

[5] In September 2016, the Company sold its interest in certain Badgley Mischka trademarks for shoes and handbags in respect of the Greater China territory for $1.2 million in cash. The Company recognized a gain of $0.1 million as a result of this transaction.

[6] 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.

[7] 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.

[8] 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.