星空传媒 Inc. Quarterly report pursuant to Section 13 or 15(d)

GOODWILL AND INTANGIBLE ASSETS AND LIABILITIES - Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]	听	听
Finite-Lived Intangible Assets, Gross	$ 220.2	听
Finite-Lived Intangible Assets, Accumulated Amortization	(30.1)	听
Finite-Lived Intangible Assets, Net	190.1	听
Finite-Lived Intangible Liabilities, Gross	(70.5)	听
Finite-Lived Intangible Liabilities, Accumulated Amortization	4.6	听
Finite-Lived Intangible Liabilities, Net	(65.9)	听
Customer Relationships [Member]	听	听
Finite-Lived Intangible Assets [Line Items]	听	听
Finite-Lived Intangible Assets, Gross	77.0	听
Finite-Lived Intangible Assets, Accumulated Amortization	(2.6)	听
Finite-Lived Intangible Assets, Net	74.4	听
Technology-Based Intangible Assets [Member]	听	听
Finite-Lived Intangible Assets [Line Items]	听	听
Finite-Lived Intangible Assets, Gross	60.0	听
Finite-Lived Intangible Assets, Accumulated Amortization	(2.1)	听
Finite-Lived Intangible Assets, Net	57.9	听
Trademarks and Trade Names [Member]	听	听
Finite-Lived Intangible Assets [Line Items]	听	听
Finite-Lived Intangible Assets, Gross	11.0	听
Finite-Lived Intangible Assets, Accumulated Amortization	(0.7)	听
Finite-Lived Intangible Assets, Net	10.3	听
Mining Permits [Member]	听	听
Finite-Lived Intangible Assets [Line Items]	听	听
Finite-Lived Intangible Assets, Gross	72.2	$ 72.2
Finite-Lived Intangible Assets, Accumulated Amortization	(24.7)	(24.1)
Finite-Lived Intangible Assets, Net	$ 47.5	$ 48.1