Investments (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 05, 2018
Investments [Line Items]
Equity method investments		$ 69,100,000	$ 90,900,000
Call price		20,000,000.0
Impairment related to partial write-down of equity method investment	$ 3,500,000	20,200,000	10,000,000.0
Purchase of additional interest in marketable equity securities		3,500,000
Investments in marketable equity securities		4,400,000	1,200,000
Investments in non-marketable equity securities		$ 61,800,000	71,800,000
fuboTV [Member]
Investments [Line Items]
Investments in non-marketable equity securities				$ 25,000,000.0
Senior secured term loan provided			$ 25,000,000.0