Discontinued Operations - Summary of Details of Entertainment Segment (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Other expenses (income):
Loss from operations of discontinued operations before income taxes	$ (2,308)	$ (26,232)
Gain on sale of Entertainment segment	(228)	104,099
Provision for income taxes	(406)	28,555
Net income (loss) from discontinued operations	(2,130)	49,312
Less: Net income attributable to non-controlling interest from discontinued operations		2,943
Net income (loss) from discontinued operations attributable to Iconix Brand Group, Inc.	(2,130)	46,369
Operating Segments | Entertainment
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Licensing revenue		53,129
Selling, general and administrative expenses		34,542
Depreciation and amortization		303
Operating income		18,284
Other expenses (income):
Interest expense		12,973
Interest income		(180)
Loss on extinguishment of debt	2,308	31,554
Foreign currency translation loss		169
Other expenses – net	2,308	44,516
Loss from operations of discontinued operations before income taxes	(2,308)	(26,232)
Gain on sale of Entertainment segment	(228)	104,099
Provision for income taxes	(406)	28,555
Net income (loss) from discontinued operations	(2,130)	49,312
Less: Net income attributable to non-controlling interest from discontinued operations		2,943
Net income (loss) from discontinued operations attributable to Iconix Brand Group, Inc.	$ (2,130)	$ 46,369