Marketable Investment Securities, Restricted Cash and Cash Equivalents, and Other Investment Securities - Other Income Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income (Expense)
Marketable investment securities - realized and unrealized gains (losses)	$ 4,604	$ 8,165	$ 90,979
Non-marketable investment securities - gains (losses) on sales/exchanges			10,488
Costs related to early redemption of debt	(483)	(3,261)	(1,470)
Gain (loss) on sale of subsidiary		7,004
Equity in earnings of affiliates	(3,714)	(2,110)	2,163
Other	11,117	2,003	2,328
Total	$ 11,524	$ 11,801	$ 104,488