Investments in Affiliates (Equity Method Investment, Summarized Financial Data) (Details) - Telesat Canada [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary Financial Data:
Revenues	$ 687,868	$ 699,596
Operating expenses	(129,770)	(137,400)
Depreciation, amortization and stock-based compensation	(212,282)	(205,451)
Other operating income (expense)	(649)	576
Operating income	345,167	357,321
Interest expense	(186,394)	(176,873)
Loss on refinancing	(86,166)
Foreign exchange (loss) gain	122,002	(203,005)
Gain (loss) on financial instruments	(42,039)	15,795
Other income (expense)	16,360	11,335
Income tax provision	(12,741)	(45,423)
Net (loss) income	156,189	(40,850)
Current assets	877,294	628,125
Total assets	4,130,337	3,942,847
Current liabilities	124,217	139,401
Long-term debt, including current portion	2,836,700	2,764,599
Total liabilities	3,504,594	3,474,504
Shareholders' equity	$ 625,743	$ 468,343