Restatement - Adjustments to Previously Reported Unaudited Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands		Sep. 30, 2015		Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents		$ 136,720		$ 128,039	$ 129,527	$ 278,789
Restricted cash		51,911		59,560
Accounts receivable, net		104,828		112,347
Deferred income tax assets		20,383
Other assets - current		39,557	[1]	44,088
Total Current Assets		353,399		354,362
Property and equipment:
Furniture, fixtures and equipment		23,749		22,704
Less: Accumulated depreciation		(16,248)		(14,946)
Property, Plant and Equipment, Net, Total		7,501		7,758
Other Assets:
Other assets		32,673		51,865
Trademarks and other intangibles, net		2,105,628	[1]	1,996,334
Deferred financing costs, net		16,188		19,842
Investments and joint ventures		145,465	[1]	110,105
Goodwill		293,849	[1]	232,776
Other Assets, Total		2,593,803
Total Assets		2,954,703		2,773,042
Current liabilities:
Accounts payable and accrued expenses		43,994		38,655
Deferred revenue		27,535		25,868
Current portion of long-term debt		351,544		61,123
Other liabilities - current		3,727		6,403
Total current liabilities		426,800		132,049
Deferred income tax liability		342,086		299,982
Long-term debt, less current maturities		1,120,098		1,332,954
Other liabilities		15,689		16,924
Total Liabilities		1,904,673		1,781,909
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 52,523		$ 39,696
Commitments and contingencies
Stockholders' Equity:
Common stock		$ 80		$ 79
Additional paid-in capital		967,541		940,922
Retained earnings		783,767		713,819
Accumulated other comprehensive loss		(51,396)		(24,186)
Less: Treasury stock		(837,424)		(812,429)
Total Iconix Brand Group, Inc. Stockholders' Equity		862,568		818,205
Non-controlling interests, net of installment payments due from non- controlling interest holders		134,939		133,232
Total Stockholders' Equity		997,507		951,437
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		2,954,703		$ 2,773,042
As Previously Reported
Current Assets:
Cash and cash equivalents		136,367
Restricted cash		51,911
Accounts receivable, net		109,090
Deferred income tax assets		20,383
Other assets - current	[1]	51,270
Total Current Assets		369,021
Property and equipment:
Furniture, fixtures and equipment		23,749
Less: Accumulated depreciation		(16,248)
Property, Plant and Equipment, Net, Total		7,501
Other Assets:
Other assets		48,466
Trademarks and other intangibles, net	[1]	2,184,532
Deferred financing costs, net		16,188
Investments and joint ventures	[1]	179,773
Goodwill	[1]	238,220
Other Assets, Total		2,667,179
Total Assets		3,043,701
Current liabilities:
Accounts payable and accrued expenses		43,926
Deferred revenue		26,945
Current portion of long-term debt		351,544
Other liabilities - current		13,884
Total current liabilities		436,299
Deferred income tax liability		362,100
Long-term debt, less current maturities		1,120,098
Other liabilities		10,424
Total Liabilities		1,928,921
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 14,761
Commitments and contingencies
Stockholders' Equity:
Common stock		$ 80
Additional paid-in capital		974,797
Retained earnings		877,655
Accumulated other comprehensive loss		(50,953)
Less: Treasury stock		(837,424)
Total Iconix Brand Group, Inc. Stockholders' Equity		964,155
Non-controlling interests, net of installment payments due from non- controlling interest holders		135,864
Total Stockholders' Equity		1,100,019
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		3,043,701
Adjustments
Current Assets:
Cash and cash equivalents		353
Accounts receivable, net		(4,262)
Other assets - current	[1]	(11,713)
Total Current Assets		(15,622)
Other Assets:
Other assets		(15,793)
Trademarks and other intangibles, net	[1]	(78,904)
Investments and joint ventures	[1]	(34,308)
Goodwill	[1]	55,629
Other Assets, Total		(73,376)
Total Assets		(88,998)
Current liabilities:
Accounts payable and accrued expenses		68
Deferred revenue		590
Other liabilities - current		(10,157)
Total current liabilities		(9,499)
Deferred income tax liability		(20,014)
Other liabilities		5,265
Total Liabilities		(24,248)
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 37,762
Commitments and contingencies
Stockholders' Equity:
Additional paid-in capital		$ (7,256)
Retained earnings		(93,888)
Accumulated other comprehensive loss		(443)
Total Iconix Brand Group, Inc. Stockholders' Equity		(101,587)
Non-controlling interests, net of installment payments due from non- controlling interest holders		(925)
Total Stockholders' Equity		(102,512)
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		$ (88,998)

[1] Included in the adjustment amounts for goodwill, trademarks and other intangibles, net, investments and joint ventures, other assets – current, and accumulated other comprehensive loss are adjustments of approximately $54.5 million, $(50.8) million, $(4.7) million, $0.1 million and $0.9 milllion, respectively, which were not part of the restatement but are to reflect the final purchase price allocation (which was completed in the fourth quarter of 2015) for the buy-out of the remaining 50% interest in Iconix China as well as the acquisitions of Strawberry Shortcake and PONY and the temporary mark-to-market adjustment associated with the available-for-sale securities acquired as part of the buy-out of the remaining 50% interest in Iconix China. Refer to Note 2 and Note 3 for further details.