Goodwill and Trademarks and Other Intangibles, net - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended			9 Months Ended		12 Months Ended
	Jul. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					$ 103,877,000			$ 103,877,000	$ 0
Changes in goodwill		$ (53,000,000)
Impairment of intangible assets, indefinite-lived					521,653,000			521,653,000
Amortization expense (credit) for intangible assets					200,000		$ (100,000)	600,000	1,000,000
Iconix SE Asia, Ltd.
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks		(22,700,000)
Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived									0
Impairment of intangible assets, finite-lived								0	0
Increase (Decrease) in indefinite-lived trademarks		(204,300,000)
Residual value					0			$ 0
Trademarks | Minimum
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, useful life								10 years
Residual value					0			$ 0
Trademarks | Maximum
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, useful life								15 years
Residual value					0			$ 0
Trademarks | Assets Held for Sale
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks										$ (204,300,000)
Trademarks | NGX, LLC
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks	$ (5,000,000)
Trademarks | Peanuts Holdings, LLC
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks		(153,600,000)
Trademarks | Peanuts Holdings, LLC | Assets Held for Sale
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks										(153,600,000)
Trademarks | Strawberry Shortcake
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks		(50,700,000)
Trademarks | Strawberry Shortcake | Assets Held for Sale
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks										$ (50,700,000)
Trademarks | Sharper Image intellectual property and related assets
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks			$ (55,600,000)
Trademarks | London Fog Korea trademark
Intangible Assets by Major Class [Line Items]
Increase (Decrease) in indefinite-lived trademarks				$ (400,000)
Mossimo License Agreement | Target
Intangible Assets by Major Class [Line Items]
License agreement expiration date								2018-10
DanskinNow License Agreement | Walmart
Intangible Assets by Major Class [Line Items]
License agreement expiration date								2019-01
Non-compete agreements and contracts | Minimum
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, useful life								1 year
Non-compete agreements and contracts | Maximum
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, useful life								15 years
Operating Segments
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived						$ 424,900,000
Operating Segments | Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived					521,800,000
Iconix SE Asia, Ltd. | Global Brand Group Asia, Ltd.
Intangible Assets by Major Class [Line Items]
Changes in goodwill		$ (3,500,000)
Men's
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					1,500,000	18,300,000
Men's | Operating Segments
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					1,500,000			$ 1,524,000	0
Impairment of intangible assets, indefinite-lived						144,600,000
Men's | Operating Segments | Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived					135,900,000
Women's
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					73,900,000	0
Women's | Operating Segments
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					73,900,000			73,939,000	0
Impairment of intangible assets, indefinite-lived						31,500,000
Women's | Operating Segments | Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived					227,600,000
Home
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					28,400,000	0
Home | Operating Segments
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					28,400,000			$ 28,414,000	0
Impairment of intangible assets, indefinite-lived						50,000,000
Home | Operating Segments | Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived					69,500,000
Entertainment
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge						0
Entertainment | Operating Segments
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived						5,100,000
International | Operating Segments
Intangible Assets by Major Class [Line Items]
Non-cash goodwill impairment charge					0				$ 0
Impairment of intangible assets, indefinite-lived						$ 193,700,000
International | Operating Segments | Trademarks
Intangible Assets by Major Class [Line Items]
Impairment of intangible assets, indefinite-lived					$ 88,800,000