Consolidated Financial Information (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
Quarterly Financial Information Disclosure [Abstract]
Licensing revenue	$ 94,653		$ 91,332		$ 97,398		$ 95,814		$ 96,009		$ 89,965		$ 95,116		$ 110,400		$ 379,197	$ 391,490	$ 390,574
Operating income (loss), net	(398,245)		27,781		51,825		55,976		48,280		45,777		61,860		64,511		(262,663)	220,428	234,978
Provision 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
Net income (loss) 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
Basic earnings per share	$ (5.44)		$ (0.11)		$ 0.28		$ 1.36		$ 0.37		$ 0.27		$ 0.48		$ 1.01		$ (3.92)	$ 2.14	$ 1.87
Diluted earnings per share	$ (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

[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.