Restatement - Adjustments to Previously Reported Unaudited Condensed Consolidated Statements of Income and Comprehensive Income (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Licensing revenue		$ 94,632	$ 95,814
Total revenue		94,632	95,814
Selling, general and administrative expenses		51,488	39,690
Depreciation and amortization		1,097	1,337
Equity earnings on joint ventures		(1,193)	(1,187)	[1]
Operating income (loss)		54,209	55,974
Other expenses, net		20,480	(40,343)	[1]
Income before income taxes		33,729	96,317
Provision for income taxes		10,608	27,272
Net income		23,121	69,045
Less: Net income attributable to non-controlling interest		4,505	3,687
Net income attributable to Iconix Brand Group, Inc.		$ 18,616	$ 65,358
Earnings per share:
Basic		$ 0.38	$ 1.36
Diluted		$ 0.37	$ 1.26
Comprehensive income		$ 33,625	$ 31,309
Comprehensive income attributable to Iconix Brand Group, Inc.		$ 29,120	27,622
As Previously Reported
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Licensing revenue			93,797
Total revenue			93,797
Selling, general and administrative expenses			39,871
Depreciation and amortization			1,337
Operating income (loss)			52,589
Other expenses, net	[1]		(40,528)
Income before income taxes			93,117
Provision for income taxes			26,365
Net income			66,752
Less: Net income attributable to non-controlling interest			3,067
Net income attributable to Iconix Brand Group, Inc.			$ 63,685
Earnings per share:
Basic			$ 1.32
Diluted			$ 1.23
Comprehensive income			$ 28,521
Comprehensive income attributable to Iconix Brand Group, Inc.			25,454
Adjustments
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Licensing revenue			2,017
Total revenue			2,017
Selling, general and administrative expenses			(181)
Equity earnings on joint ventures	[1]		(1,187)
Operating income (loss)			3,385
Other expenses, net	[1]		185
Income before income taxes			3,200
Provision for income taxes			907
Net income			2,293
Less: Net income attributable to non-controlling interest			620
Net income attributable to Iconix Brand Group, Inc.			$ 1,673
Earnings per share:
Basic			$ 0.04
Diluted			$ 0.03
Comprehensive income			$ 2,788
Comprehensive income attributable to Iconix Brand Group, Inc.			$ 2,168

[1] Equity earnings from joint ventures was previously reported within other expenses – net and has been reclassified and is being presented as a component of operating income.