Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Licensing revenue	$ 35,471,000	$ 46,224,000	$ 105,806,000	$ 144,984,000
Type of Revenue [Extensible List]	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember
Selling, general and administrative expenses	$ 26,318,000	$ 30,197,000	$ 60,846,000	$ 92,437,000
Loss on termination of licenses				5,650,000
Depreciation and amortization	421,000	502,000	1,393,000	1,788,000
Equity earnings on joint ventures	(153,000)	(967,000)	(2,290,000)	(2,212,000)
Gain on sale of trademarks				(1,268,000)
Goodwill impairment			0	37,812,000
Trademark impairment		4,386,000		77,721,000
Investment impairment	17,000,000		17,000,000
Operating income (loss)	(8,115,000)	12,106,000	28,857,000	(66,944,000)
Other expenses (income):
Interest expense	14,430,000	14,944,000	43,399,000	44,320,000
Interest income	(96,000)	(89,000)	(259,000)	(304,000)
Other (income) loss, net	11,971,000	(25,787,000)	(6,821,000)	(84,001,000)
Gain on extinguishment of debt				(4,473,000)
Foreign currency translation (gain) loss	391,000	301,000	760,000	453,000
Other expenses (income) – net	26,696,000	(10,631,000)	37,079,000	(44,005,000)
Income (loss) before income taxes	(34,811,000)	22,737,000	(8,222,000)	(22,939,000)
(Benefit) provision for income taxes	(585,000)	1,026,000	1,253,000	(128,000)
Net income (loss)	(34,226,000)	21,711,000	(9,475,000)	(22,811,000)
Less: Net income attributable to non-controlling interest	1,482,000	1,487,000	7,017,000	8,635,000
Net income (loss) attributable to Iconix Brand Group, Inc.	$ (35,708,000)	$ 20,224,000	$ (16,492,000)	$ (31,446,000)
Earnings (loss) per share:
Basic	$ (3.07)	$ 2.81	$ (1.62)	$ (4.87)
Diluted	$ (3.07)	$ 0.26	$ (1.62)	$ (7.35)
Weighted average number of common shares outstanding:
Basic	11,631	7,184	10,169	6,458
Diluted	11,631	17,591	10,169	12,310