Goodwill and Trademarks and Other Intangibles, net - Additional Information (Detail) - USD ($)		3 Months Ended			9 Months Ended
	Oct. 15, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jul. 31, 2018	Dec. 31, 2017
Intangible Assets By Major Class [Line Items]
Non-cash impairment charge				$ 103,877,000	$ 37,812,000	$ 103,877,000
Goodwill		$ 26,099,000			26,099,000			$ 63,882,000
Trademark impairment		4,386,000		521,653,000	77,721,000	521,653,000
Trademarks and other intangibles, net		397,703,000			397,703,000			465,722,000
Amortization of trademarks and other intangibles				$ 200,000	205,000	567,000
Trademarks
Intangible Assets By Major Class [Line Items]
Impairment of the definite-lived trademarks					0	$ 0
Trademarks
Intangible Assets By Major Class [Line Items]
Trademarks and other intangibles, net		12,300,000			12,300,000
Residual value		$ 0			$ 0
Iconix Australia
Intangible Assets By Major Class [Line Items]
Ownership interest acquired		5.00%			5.00%		5.00%
Goodwill							$ 29,000
Maximum
Intangible Assets By Major Class [Line Items]
Amortization of trademarks and other intangibles		$ 100,000
Maximum | Trademarks
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					15 years
Maximum | Non-compete agreements and contracts
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					15 years
Maximum | Trademarks
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					15 years
Maximum | Iconix Australia
Intangible Assets By Major Class [Line Items]
Goodwill							$ 100,000
Minimum | Trademarks
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					10 years
Minimum | Non-compete agreements and contracts
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					1 year
Minimum | Trademarks
Intangible Assets By Major Class [Line Items]
Finite-lived intangible assets, useful life					10 years
Women's
Intangible Assets By Major Class [Line Items]
Non-cash impairment charge			$ 37,800,000		$ 37,812,000
Goodwill								$ 37,812,000
Women's | Trademarks
Intangible Assets By Major Class [Line Items]
Trademark impairment		$ 4,400,000			$ 73,300,000
Women's | Subsequent Event | Trademarks
Intangible Assets By Major Class [Line Items]
Trademark impairment	$ 0