Restatement of Previously Issued Financial Statements - Fourth Reconciliation Of Previously Reported And Restated Selected Financial Data - Statements of Income (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2014	[2]	Sep. 30, 2014	[2]	Jun. 30, 2014	[2]	Mar. 31, 2014	[2]	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Licensing revenue		$ 94,653		$ 91,332		$ 97,398		$ 95,814		$ 96,009		$ 89,965		$ 95,116		$ 110,400		$ 379,197	$ 391,490		$ 390,574
Total revenue																		379,197	391,490		390,574
Selling, general and administrative expenses																		209,666	188,786		173,161
Gains on sale of trademarks	[3]																		(6,399)		(7,354)
Equity earnings on joint ventures																		(5,330)	(11,325)	[4]	(10,211)	[4]
Operating income (loss)		(398,245)		27,781		51,825		55,976		48,280		45,777		61,860		64,511		(262,663)	220,428		234,978
Other expenses - net	[4]																		53,318		68,091
Income (loss) before income taxes																		(284,274)	167,110		166,887
Provision (benefit) for income taxes		(140,427)		6,275		11,536		27,272		5,210		8,867		14,213		19,998		(95,344)	48,288		49,595
Net (loss) income		(275,976)		(954)		18,955		69,045		22,459		16,382		26,949		53,032		(188,930)	118,822		117,292
Less: Net income attributable to non-controlling interest																		373	15,099		12,303
Net (loss) income attributable to Iconix Brand Group, Inc.		$ (263,014)		$ (5,387)		$ 13,739		$ 65,359		$ 17,526		$ 12,855		$ 23,427		$ 49,915		$ (189,303)	$ 103,723		$ 104,989
Earnings (loss) per share:
Basic		$ (5.44)		$ (0.11)		$ 0.28		$ 1.36		$ 0.37		$ 0.27		$ 0.48		$ 1.01		$ (3.92)	$ 2.14		$ 1.87
Diluted		$ (5.44)		$ (0.11)		$ 0.28		$ 1.26		$ 0.32		$ 0.22		$ 0.40		$ 0.86		$ (3.92)	$ 1.81		$ 1.73
Comprehensive income (loss)		$ (286,413)		$ 3,097		$ 26,370		$ 31,309		$ 14,396		$ (8,533)		$ 21,785		$ 50,502		$ (225,637)	$ 78,150		$ 133,778
Comprehensive income (loss) attributable to Iconix Brand Group, Inc.		$ (273,451)		$ (1,336)		$ 21,155		$ 27,622		$ 10,177		$ (12,275)		$ 17,987		$ 47,162		$ (226,010)	63,051		121,475
As Previously Reported
Licensing revenue																			394,157		398,047
Other revenue	[3]																		45,840		32,579
Total revenue																			439,997		430,626
Selling, general and administrative expenses																			190,153		173,215
Operating income (loss)																			249,844		257,411
Other expenses - net	[4]																		26,667		56,749
Income (loss) before income taxes																			223,177		200,662
Provision (benefit) for income taxes																			59,641		58,075
Net (loss) income																			163,536		142,587
Less: Net income attributable to non-controlling interest																			14,693		14,539
Net (loss) income attributable to Iconix Brand Group, Inc.																			$ 148,843		$ 128,048
Earnings (loss) per share:
Basic																			$ 3.07		$ 2.28
Diluted																			$ 2.59		$ 2.11
Comprehensive income (loss)																			$ 122,864		$ 159,073
Comprehensive income (loss) attributable to Iconix Brand Group, Inc.																			108,171		144,534
Adjustments
Licensing revenue																			(2,667)		(7,473)
Other revenue	[3]																		(45,840)		(32,579)
Total revenue																			(48,507)		(40,052)
Selling, general and administrative expenses																			(1,367)		(54)
Gains on sale of trademarks	[3]																		(6,399)		(7,354)
Equity earnings on joint ventures	[4]																		(11,325)		(10,211)
Operating income (loss)																			(29,416)		(22,433)
Other expenses - net	[4]																		26,651		11,342
Income (loss) before income taxes																			(56,067)		(33,775)
Provision (benefit) for income taxes																			(11,353)		(8,480)
Net (loss) income																			(44,714)		(25,295)
Less: Net income attributable to non-controlling interest																			406		(2,236)
Net (loss) income attributable to Iconix Brand Group, Inc.																			$ (45,120)		$ (23,059)
Earnings (loss) per share:
Basic																			$ (0.93)		$ (0.41)
Diluted																			$ (0.78)		$ (0.38)
Comprehensive income (loss)																			$ (44,714)		$ (25,295)
Comprehensive income (loss) attributable to Iconix Brand Group, Inc.																			$ (45,120)		$ (23,059)

[1] FY 2015: Operating income (loss), net includes a non-cash impairment charge of $437.5 million primarily related to the men’s brands recorded in the fourth quarter. Included in net income (loss) attributable to Iconix Brand Group, Inc. is a non-cash pre-tax re-measurement gain of approximately $50.0 million related to the purchase of the remaining interest in Iconix China in the first quarter.

[2] FY 2014 (Restated): Operating income, net includes a net gain of $6.4 million on the sale of the “sharperimage.com” domain name and certain categories under the Sharper Image trademark in the second quarter. Included in net income attributable to Iconix Brand Group, Inc is a non-cash pre-tax re-measurement gain of approximately $34.7 million related to the purchase of the remaining interest in Iconix Latin America in the first quarter.

[3] (1) Gains on sale of trademarks was previously reported as other revenue. Many of the gains recorded upon formation of certain joint ventures were reversed as a result of consolidation. The gains that were not impacted by consolidation, and therefore not reversed, have been reclassified and are being presented as a separate line item above operating income.

[4] (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.