Restatement - Adjustments to Previously Reported Unaudited Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands		Jun. 30, 2015		Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents		$ 117,943		$ 128,039	$ 131,863	$ 278,789
Restricted cash		64,923		59,560
Accounts receivable, net		121,491		112,347
Deferred income tax assets		21,436		10,328
Other assets - current		41,502	[1]	44,088
Total Current Assets		367,295		354,362
Property and equipment:
Furniture, fixtures and equipment		23,435		22,704
Less: Accumulated depreciation		(15,839)		(14,946)
Property, Plant and Equipment, Net, Total		7,596		7,758
Other Assets:
Other assets		34,455		51,865
Net Carrying Amount		2,103,164	[1]	1,996,334
Deferred financing costs, net		17,383		19,842
Investments and joint ventures		148,453	[1]	110,105
Goodwill		291,713	[1]	232,776
Other Assets, Total		2,595,168		2,410,922
Total Assets		2,970,059		2,773,042
Current liabilities:
Accounts payable and accrued expenses		44,785		38,655
Deferred revenue		30,132		25,868
Current portion of long-term debt		347,918		61,123
Other liabilities - current		3,500		6,403
Total current liabilities		426,335		132,049
Deferred income tax liability		339,120		299,982
Long-term debt, less current maturities		1,130,667		1,332,954
Other liabilities		15,835		16,924
Total Liabilities		1,911,957		1,781,909
Redeemable Non-Controlling Interest		$ 47,154		$ 39,696
Commitments and contingencies
Stockholders' Equity:
Common stock, $.001 par value shares authorized 150,000; shares issued 80,339 and 79,263, respectively		$ 80		$ 79
Additional paid-in capital		962,812		940,922
Retained earnings		790,418		713,819
Accumulated other comprehensive loss		(54,497)		(24,186)
Less: Treasury stock - 32,021 and 31,310 shares at cost, respectively		(836,501)		(812,429)
Total Iconix Brand Group, Inc. Stockholders' Equity		862,312		818,205
Non-controlling interest		148,636		133,232
Total Stockholders' Equity		1,010,948		951,437
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		2,970,059		$ 2,773,042
As Previously Reported
Current Assets:
Cash and cash equivalents		117,874
Restricted cash		64,923
Accounts receivable, net		126,257
Deferred income tax assets		21,436
Other assets - current	[1]	49,780
Total Current Assets		380,270
Property and equipment:
Furniture, fixtures and equipment		23,435
Less: Accumulated depreciation		(15,839)
Property, Plant and Equipment, Net, Total		7,596
Other Assets:
Other assets		52,341
Net Carrying Amount	[1]	2,183,447
Deferred financing costs, net		17,383
Investments and joint ventures	[1]	182,760
Goodwill	[1]	238,187
Other Assets, Total		2,674,118
Total Assets		3,061,984
Current liabilities:
Accounts payable and accrued expenses		45,173
Deferred revenue		29,439
Current portion of long-term debt		347,918
Other liabilities - current		15,447
Total current liabilities		437,977
Deferred income tax liability		359,721
Long-term debt, less current maturities		1,130,667
Other liabilities		10,570
Total Liabilities		1,938,935
Redeemable Non-Controlling Interest		$ 14,582
Commitments and contingencies
Stockholders' Equity:
Common stock, $.001 par value shares authorized 150,000; shares issued 80,339 and 79,263, respectively		$ 80
Additional paid-in capital		970,245
Retained earnings		883,997
Accumulated other comprehensive loss		(55,003)
Less: Treasury stock - 32,021 and 31,310 shares at cost, respectively		(836,501)
Total Iconix Brand Group, Inc. Stockholders' Equity		962,818
Non-controlling interest		145,649
Total Stockholders' Equity		1,108,467
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		3,061,984
Adjustments
Current Assets:
Cash and cash equivalents		69
Accounts receivable, net		(4,766)
Other assets - current	[1]	(8,278)
Total Current Assets		(12,975)
Other Assets:
Other assets		(17,886)
Net Carrying Amount	[1]	(80,283)
Investments and joint ventures	[1]	(34,307)
Goodwill	[1]	53,526
Other Assets, Total		(78,950)
Total Assets		(91,925)
Current liabilities:
Accounts payable and accrued expenses		(388)
Deferred revenue		693
Other liabilities - current		(11,947)
Total current liabilities		(11,642)
Deferred income tax liability		(20,601)
Other liabilities		5,265
Total Liabilities		(26,978)
Redeemable Non-Controlling Interest		$ 32,572
Commitments and contingencies
Stockholders' Equity:
Additional paid-in capital		$ (7,433)
Retained earnings		(93,579)
Accumulated other comprehensive loss		506
Total Iconix Brand Group, Inc. Stockholders' Equity		(100,506)
Non-controlling interest		2,987
Total Stockholders' Equity		(97,519)
Total Liabilities, Redeemable Non-Controlling Interest and Stockholders' Equity		$ (91,925)

[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, $(52.1) million, $(3.8) 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.