Derivative Instruments (Realized and Unrealized Gains (Losses) on Derivatives) (Schedule and Footnotes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Gain (loss) on derivative instruments, net	$ (717.8)	$ 582.1	$ 199.8	$ 652.2
Cross-currency and interest rate derivative contracts
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(755.4)	567.3	(222.5)	549.1
Equity-related derivative instruments:
Derivative [Line Items]
Gain (loss) on derivative instruments, net	77.1	(100.8)	454.7	9.0
ITV Collar
Derivative [Line Items]
Gain (loss) on derivative instruments, net	82.9	(106.8)	433.2	(7.0)
Lionsgate Forward
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(5.7)	5.5	0.8	15.1
Other
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(0.1)	0.5	20.7	0.9
Foreign currency forward and option contracts
Derivative [Line Items]
Gain (loss) on derivative instruments, net	(39.2)	116.3	(31.8)	94.1
Other
Derivative [Line Items]
Gain (loss) on derivative instruments, net	$ (0.3)	$ (0.7)	$ (0.6)	$ 0.0