Net Revenues by Type of License and Information by Geographic Region (Detail) - USD ($) $ in Thousands		3 Months Ended																6 Months Ended		9 Months Ended		12 Months Ended
		Dec. 31, 2014	[1]	Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013	[2]	Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Licensing revenue		$ 94,822		$ 91,612	[1]	$ 96,071	[1]	$ 111,652	[1]	$ 88,265		$ 99,135	[2]	$ 105,356	[2]	$ 105,062	[2]	$ 207,723	$ 210,418	$ 299,334	$ 309,553	$ 394,157	$ 398,047	$ 341,685
Operating income (loss)		50,317		63,414	[1]	68,254	[1]	67,859	[1]	58,191		61,470	[2]	71,514	[2]	66,236	[2]	136,113	137,750	199,527	199,220	249,844	257,411	215,450
Other revenue		$ 7,151		18,680	[1]	16,038	[1]	3,971	[1]	$ 14,999		8,040	[2]	9,769	[2]			20,009	9,769	38,690	17,809	45,840	32,579	12,133
Total revenue				110,292		112,109		115,623				107,175		115,125		105,062		227,732	220,187	338,024	327,362	439,997	430,626	353,818
Operating Segment
Segment Reporting Information [Line Items]
Other revenue								3,971														45,840	32,579	12,133
Operating Segment | United States
Segment Reporting Information [Line Items]
Total revenue				64,573		73,755		82,270				75,783		71,326		74,856		156,025	146,272	220,598	221,964	282,936	292,619	273,903
Operating Segment | Japan
Segment Reporting Information [Line Items]
Total revenue				6,565		7,630		8,888				9,754		5,806		6,177		16,518	11,893	23,084	21,738	31,048	29,734	36,432
Operating Segment | Other
Segment Reporting Information [Line Items]
Total revenue	[3]			39,154		30,724		24,465				21,638		37,993		24,029		55,189	62,022	94,342	83,660	126,013	108,273	43,483
Operating Segment | Reportable Segment | Men's
Segment Reporting Information [Line Items]
Licensing revenue				24,433		25,742		23,377				36,128		39,098		38,273		49,119	77,371	73,552	113,499	98,910	143,916	99,093
Operating income (loss)				10,818		14,970		15,107				23,848		28,962		30,567		30,077	59,529	40,895	83,376	51,728	97,448	74,040
Operating Segment | Reportable Segment | Women's
Segment Reporting Information [Line Items]
Licensing revenue				32,998		39,985		41,452				32,159		38,268		37,756		81,437	76,024	114,435	108,182	148,482	138,262	120,743
Operating income (loss)				27,022		34,595		35,553				26,324		32,764		33,729		70,148	66,493	97,170	92,818	124,681	118,454	105,036
Operating Segment | Reportable Segment | Home
Segment Reporting Information [Line Items]
Licensing revenue				10,968		11,242		10,979				10,740		10,139		10,894		22,221	21,033	33,189	31,773	43,694	40,920	40,527
Operating income (loss)				8,959		9,416		9,568				9,130		8,179		9,260		18,985	17,440	27,944	26,570	34,926	35,435	34,122
Operating Segment | Reportable Segment | Entertainment
Segment Reporting Information [Line Items]
Licensing revenue				23,213		19,102		35,844				20,109		17,852		18,139		54,946	35,990	78,158	56,099	103,071	74,949	81,322
Operating income (loss)				8,742		3,498		12,112				6,162		4,649		5,500		15,610	10,149	24,351	16,310	31,018	21,319	23,613
Operating Segment | Reportable Segment | Direct-to-retail license
Segment Reporting Information [Line Items]
Licensing revenue				34,949		46,176		43,054				35,663		43,237		40,845		89,229	84,082	124,178	119,745	156,848	147,846	150,245
Operating Segment | Reportable Segment | Wholesale licenses
Segment Reporting Information [Line Items]
Licensing revenue				45,963		42,122		44,451				56,479		55,074		58,881		86,573	113,955	132,535	170,434	183,291	225,186	165,082
Operating Segment | Reportable Segment | Other licenses
Segment Reporting Information [Line Items]
Licensing revenue								24,148								5,336						54,018	25,015	26,358
Operating Segment | Reportable Segment | Entertainment and other
Segment Reporting Information [Line Items]
Licensing revenue				29,380		23,811						15,033		16,814				51,930	22,150	81,311	37,183
Operating Segment | Reportable Segment | Corporate Segment
Segment Reporting Information [Line Items]
Licensing revenue				18,680		16,038		3,971				8,040		9,769				20,009	9,769	38,690	17,809	45,840	32,579	12,133
Operating income (loss)				$ 7,873		$ 5,775		$ (4,481)				$ (3,994)		$ (3,040)		$ (12,820)		$ 1,293	$ (15,861)	$ 9,167	$ (19,854)	$ 7,491	$ (15,245)	$ (21,361)

[1] FY 2014 (Restated): Other revenue includes a net gain of approximately $4.0 million related to the Iconix LC Partners U.S. transaction in the first quarter, a net gain of approximately $8.3 million and $18.7 million related to additional Iconix SE Asia transactions in the second and third quarter, respectively, a net gain of $7.8 million on the sale of the "sharperimage.com" domain name and certain categories under the Sharper Image trademark in the second quarter, and net gain of $7.2 million related to the Iconix Middle East transaction in the fourth quarter. See Note 3 for a description of these transactions. Included in net income attributable to Iconix Brand Group, Inc is a non-cash pre-tax re-measurement gain of approximately $37.9 million related to the purchase of the remaining interest in Iconix Latin America in the first quarter.

[2] FY 2013 (Restated): Other revenue includes a net gain of approximately $9.8 million related to the Iconix Canada transaction in the second quarter, a net gain of approximately $5.1 million related to the Iconix Australia transaction in the third quarter, and net gains of $2.7 million, $2.3 million, and $10.0 million related to the Iconix SE Asia, Iconix Israel and Umbro Korea transactions, respectively, in the fourth quarter. See Note 3 for a description of these transactions.

[3] No single country represented 10% of the Company's revenues in the periods presented within "Other" on this table.