Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Licensing revenue	$ 50,212	$ 61,647	$ 98,761	$ 120,370
Type of Revenue [Extensible List]	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember
Selling, general and administrative expenses	$ 28,643	$ 26,802	$ 62,241	$ 52,192
Loss on termination of licenses	5,650	23,230	5,650	23,230
Depreciation and amortization	632	571	1,286	1,223
Equity earnings on joint ventures	(1,149)	(1,059)	(1,245)	(1,992)
Gain on deconsolidation of joint venture		(3,772)		(3,772)
Gain on sale of trademarks	(125)		(1,268)
Goodwill impairment	37,812		37,812	0
Trademark impairment	73,335		73,335
Operating (loss) income	(94,586)	15,875	(79,050)	49,489
Other expenses (income):
Interest expense	14,827	14,130	29,376	28,876
Interest income	(92)	(141)	(214)	(267)
Other income	(32,083)		(58,215)	(1)
Loss (gain) on extinguishment of debt		13,919	(4,473)	19,400
Foreign currency translation loss	704	3,416	152	3,845
Other (income) expenses – net	(16,644)	31,324	(33,374)	51,853
Loss from continuing operations before income taxes	(77,942)	(15,449)	(45,676)	(2,364)
(Benefit) Provision for income taxes	(2,804)	(5,501)	(1,154)	386
Net loss from continuing operations	(75,138)	(9,948)	(44,522)	(2,750)
Less: Net income attributable to non-controlling interest from continuing operations	4,291	3,904	7,148	6,386
Net loss from continuing operations attributable to Iconix Brand Group, Inc.	(79,429)	(13,852)	(51,670)	(9,136)
Loss from discontinued operations before income taxes		(11,140)		(23,924)
Gain on sale of Entertainment segment		104,327		104,327
Provision for income taxes		34,060		28,962
Net income from discontinued operations		59,127		51,441
Less: Net income attributable to non-controlling interest from discontinued operations		1,634		2,943
Net income from discontinued operations attributable to Iconix Brand Group, Inc.		57,493		48,498
Net (loss) income attributable to Iconix Brand Group, Inc.	$ (79,429)	$ 43,641	$ (51,670)	$ 39,362
(Loss) earnings per share - basic:
Continuing operations	$ (1.26)	$ (0.26)	$ (0.91)	$ (0.20)
Discontinued operations		1.01		0.85
(Loss) earnings per share - basic	(1.26)	0.75	(0.91)	0.65
(Loss) earnings per share - diluted:
Continuing operations	(1.26)	(0.26)	(0.91)	(0.19)
Discontinued operations		1.00		0.84
(Loss) earnings per share - diluted	$ (1.26)	$ 0.74	$ (0.91)	$ 0.65
Weighted average number of common shares outstanding:
Basic	65,976	57,082	62,566	57,026
Diluted	65,976	57,568	62,566	57,568