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

FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	听	听	听
Cash equivalents	$ 526.6	听	$ 616.9
Derivative assets	93.6	$ 51.0	39.4
Total Asset	620.2	听	656.3
Derivative Liability	4.4	听	2.7
Total Liability	4.4	听	2.7
Fair Value, Inputs, Level 1 [Member]	听	听	听
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	听	听	听
Cash equivalents	36.0	听	66.3
Derivative assets	0.0	听	0.0
Total Asset	36.0	听	66.3
Derivative Liability	0.0	听	0.0
Total Liability	0.0	听	0.0
Fair Value, Inputs, Level 2 [Member]	听	听	听
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	听	听	听
Cash equivalents	490.6	听	550.6
Derivative assets	0.0	听	0.0
Total Asset	490.6	听	550.6
Derivative Liability	0.2	听	0.3
Total Liability	0.2	听	0.3
Fair Value, Inputs, Level 3 [Member]	听	听	听
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	听	听	听
Cash equivalents	0.0	听	0.0
Derivative assets	93.6	听	39.4
Total Asset	93.6	听	39.4
Derivative Liability	4.2	听	2.4
Total Liability	$ 4.2	听	$ 2.4