Investments in Affiliates (Equity Method Investment, Summarized Financial Data) (Details) - Telesat Canada [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Summary Financial Data:
Revenues	$ 158,565	$ 167,644
Operating expenses	(35,855)	(40,569)
Depreciation and amortization	(45,417)	(51,208)
Other operating income (expense)	(167)	(55)
Operating income	77,126	75,812
Interest expense	(41,547)	(46,843)
Foreign exchange (loss) gain	(221,643)	52,469
Gain (loss) on financial instruments	(7,005)	(15,112)
Other income (expense)	4,078	3,834
Income tax benefit (provision)	682	(4,555)
Net (loss) income	(188,309)	$ 65,605
Current assets	934,012		$ 877,294
Total assets	3,938,886		4,130,337
Current liabilities	143,850		124,217
Long-term debt, including current portion	2,834,182		2,836,700
Total liabilities	3,468,535		3,504,594
Shareholders' equity	$ 470,351		$ 625,743