Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Impaired Long Lived Assets Held And Used [Line Items]
Impairment of long-lived assets		$ 0	$ 0
Impairment of equity method investment		26,613,000	2,500,000
Fair value of other equity investments	$ 0	0	1,000,000
Decrease in fair value of other equity investments			(300,000)
Impairment loss of contract assets		5,143,000	$ 1,777,000
MG Icon
Impaired Long Lived Assets Held And Used [Line Items]
Impairment of equity method investment	9,600,000	9,600,000
Payments to acquire ownership interest	$ 2,600,000	2,600
Marcy Media Holdings
Impaired Long Lived Assets Held And Used [Line Items]
Impairment of equity method investment		17,000,000
Iconix China
Impaired Long Lived Assets Held And Used [Line Items]
Proceeds from sale of joint venture partners' interest		700,000
New York Office Space
Impaired Long Lived Assets Held And Used [Line Items]
Impairment loss of contract assets		$ 1,800,000