Reconciliation of Consideration Paid and Estimated Fair Value of Assets Acquired (Detail) - USD ($) $ in Thousands	1 Months Ended					3 Months Ended		12 Months Ended
	Mar. 31, 2015	Feb. 28, 2015	Feb. 28, 2014	Jan. 31, 2014	Feb. 28, 2013	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid					$ 39,614
Gain on re-measurement of initial equity investment								$ 49,990	$ 28,898
Goodwill								257,095	$ 232,776	$ 232,014
Iconix Europe
Business Acquisition [Line Items]
Fair Value of non-controlling interest				$ 13,800
Book value of Company equity investment prior to 2015 Buy-out				19,651
Business Combination Reconciliation Of Cash Paid And Fair Value Of Sellers Non-controlling Interest				27,600
Trademarks				27,000
Cash				677
Working capital deficit				(77)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net				27,600
Loss on re-measurement of initial equity investment				$ (5,851)
Iconix Latin America
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid			$ 42,000
Fair Value of non-controlling interest			42,698
Less: note receivable owed to the Company			(1,695)
Add: accrued distributions due to New Brands			997
Book value of Company equity investment prior to 2015 Buy-out			7,950
Gain on re-measurement of initial equity investment			34,748				$ 34,700
Business Combination Reconciliation Of Cash Paid And Fair Value Of Sellers Non-controlling Interest			85,396
Trademarks			82,400
Cash			1,842
Working capital deficit			(676)
Goodwill			1,130
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net			85,396
Buffalo International Unlimited Liability Corporation
Business Acquisition [Line Items]
Fair Value of non-controlling interest					59,489
Business Combination Reconciliation Of Cash Paid And Fair Value Of Sellers Non-controlling Interest					99,103
Trademarks					102,643
Note receivable					36,886
Goodwill					7,131
Deferred tax liability					(14,011)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net					99,103
Licensing contracts | Iconix Latin America
Business Acquisition [Line Items]
Finite intangible assets			$ 700
Licensing contracts | Buffalo International Unlimited Liability Corporation
Business Acquisition [Line Items]
Finite intangible assets					2,400
Non-compete agreements | Buffalo International Unlimited Liability Corporation
Business Acquisition [Line Items]
Finite intangible assets					$ 940
Pony International, LLC.
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid		$ 37,000						37,000
Fair Value of non-controlling interest		12,333
Trademarks		32,381
Accounts receivable		2,000
Goodwill		14,702
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		49,333
Pony International, LLC. | Licensing contracts
Business Acquisition [Line Items]
Finite intangible assets		$ 250
Iconix China
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid	$ 40,400
Fair Value of non-controlling interest	57,372					$ 57,372		57,372
Book value of Company equity investment prior to 2015 Buy-out								7,382
Gain on re-measurement of initial equity investment						50,000		49,990
Business Combination Reconciliation Of Cash Paid And Fair Value Of Sellers Non-controlling Interest								114,744
Trademarks								40,501
Investments in private companies								38,870
Cash								20,184
Other assets								5,997
Accrued expenses								(447)
Goodwill								9,639
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net								114,744
Iconix China | Novel
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid	40,400
Shares issued	15,703					15,703
Offset of accounts receivable	1,269					1,269
Strawberry Shortcake
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid	105,000							$ 95,000
Trademarks	55,761					55,761
Accounts receivable	3,397					3,397
Goodwill	35,375					35,375
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	95,000					95,000
Strawberry Shortcake | American Greetings Corporation
Business Acquisition [Line Items]
Business acquisition purchase price, cash paid	95,000
Strawberry Shortcake | Licensing contracts
Business Acquisition [Line Items]
Finite intangible assets	$ 467					$ 467