Restatement - Adjustments to Previously Reported Unaudited Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands		Mar. 31, 2015		Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents		$ 86,801		$ 128,039	$ 152,100	$ 278,789
Restricted cash		43,550		59,560
Accounts receivable, net		119,774		112,347
Deferred income tax assets		10,326		10,328
Other assets – current		40,519	[1]	44,088
Total Current Assets		300,970		354,362
Property and equipment:
Furniture, fixtures and equipment		23,658		22,704
Less: Accumulated depreciation		(15,439)		(14,946)
Property, Plant and Equipment, Net, Total		8,219		7,758
Other Assets:
Other assets		50,450		51,865
Trademarks and other intangibles, net		2,099,020	[1]	1,996,334
Deferred financing costs, net		18,601		19,842
Investments and joint ventures		149,208	[1]	110,105
Goodwill		292,734	[1]	232,776
Other Assets, Total		2,610,013		2,410,922
Total Assets		2,919,202		2,773,042
Current liabilities:
Accounts payable and accrued expenses		43,421		38,655
Deferred revenue		23,195		25,868
Current portion of long-term debt		61,123		61,123
Other liabilities – current		6,214		6,403
Total current liabilities		133,953		132,049
Deferred income tax liability		312,605		299,982
Long-term debt, less current maturities		1,425,189		1,332,954
Other liabilities		15,980		16,924
Total Liabilities		1,887,727		1,781,909
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 39,804		$ 39,696
Commitments and contingencies
Stockholders’ Equity:
Common stock		$ 80		$ 79
Additional paid-in capital		959,252		940,922
Retained earnings		777,928		713,819
Accumulated other comprehensive loss		(61,912)		(24,186)
Less: Treasury stock		(829,409)		(812,429)
Total Iconix Brand Group, Inc. Stockholders’ Equity		845,939		818,205
Non-controlling interests, net of installment payments due from non-controlling interest holders		145,732		133,232
Total Stockholders’ Equity		991,671		951,437
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders’ Equity		2,919,202		$ 2,773,042
As Previously Reported
Current Assets:
Cash and cash equivalents		86,751
Restricted cash		43,550
Accounts receivable, net		122,273
Deferred income tax assets		10,326
Other assets – current	[1]	60,291
Total Current Assets		323,191
Property and equipment:
Furniture, fixtures and equipment		23,658
Less: Accumulated depreciation		(15,439)
Property, Plant and Equipment, Net, Total		8,219
Other Assets:
Other assets		64,996
Trademarks and other intangibles, net	[1]	2,179,892
Deferred financing costs, net		18,601
Investments and joint ventures	[1]	181,917
Goodwill	[1]	239,198
Other Assets, Total		2,684,604
Total Assets		3,016,014
Current liabilities:
Accounts payable and accrued expenses		44,017
Deferred revenue		22,470
Current portion of long-term debt		61,123
Other liabilities – current		15,895
Total current liabilities		143,505
Deferred income tax liability		332,535
Long-term debt, less current maturities		1,425,189
Other liabilities		10,715
Total Liabilities		1,911,944
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 14,403
Commitments and contingencies
Stockholders’ Equity:
Common stock		$ 80
Additional paid-in capital		966,865
Retained earnings		869,211
Accumulated other comprehensive loss		(62,417)
Less: Treasury stock		(829,409)
Total Iconix Brand Group, Inc. Stockholders’ Equity		944,330
Non-controlling interests, net of installment payments due from non-controlling interest holders		145,337
Total Stockholders’ Equity		1,089,667
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders’ Equity		3,016,014
Adjustments
Current Assets:
Cash and cash equivalents		50
Accounts receivable, net		(2,499)
Other assets – current	[1]	(19,772)
Total Current Assets		(22,221)
Other Assets:
Other assets		(14,546)
Trademarks and other intangibles, net	[1]	(80,872)
Investments and joint ventures	[1]	(32,709)
Goodwill	[1]	53,536
Other Assets, Total		(74,591)
Total Assets		(96,812)
Current liabilities:
Accounts payable and accrued expenses		(596)
Deferred revenue		725
Other liabilities – current		(9,681)
Total current liabilities		(9,552)
Deferred income tax liability		(19,930)
Other liabilities		5,265
Total Liabilities		(24,217)
Redeemable Non-Controlling Interests, net of installment payments due from non-controlling interest holders		$ 25,401
Commitments and contingencies
Stockholders’ Equity:
Additional paid-in capital		$ (7,613)
Retained earnings		(91,283)
Accumulated other comprehensive loss		505
Total Iconix Brand Group, Inc. Stockholders’ Equity		(98,391)
Non-controlling interests, net of installment payments due from non-controlling interest holders		395
Total Stockholders’ Equity		(97,996)
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders’ Equity		$ (96,812)

[1] Included in the adjustment amounts for goodwill, trademarks and other intangibles, net, investments and joint ventures, and other assets – current are adjustments of $52.5 million, $(52.7) million, $(3.2) million and $3.4 million, 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. Refer to Note 2 and 3 for further details.