Investments in Affiliates (Equity in Net Income (Losses) of Affiliates) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Equity in net income (loss) of affiliates	$ 43,372	$ 6,948	$ 183,086	$ 96,799
Telesat Holdings Inc [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net income (loss) of affiliates	$ 43,372	$ 6,948	$ 183,086	$ 96,799