Investments in Affiliates (Equity Method Investment, Summarized Financial Data) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Telesat Holdings Inc [Member]
Statement of Operations Data:
Revenues	$ 167,538	$ 180,012	$ 344,649	$ 350,513
Operating expenses	(36,477)	(35,658)	(78,149)	(68,227)
Depreciation, amortization and stock-based compensation	(47,637)	(50,378)	(96,134)	(97,391)
Gain (loss) on disposition of long lived asset	2	(96)	(16)	(1,913)
Operating income (loss)	83,426	93,880	170,350	182,982
Interest expense	(37,071)	(35,149)	(73,864)	(70,351)
Foreign exchange gains (losses)	72,309	18,364	90,160	154,271
Gains (losses) on financial instruments	(7,316)	6,666	(10,929)	(5,951)
Other income (expense)	(997)	929	(852)	1,783
Income tax provision	(9,619)	(15,049)	(19,457)	(26,069)
Net income (loss)	100,732	69,641	155,408	236,665
Current assets	346,596		346,596		$ 678,361
Total assets	3,917,216		3,917,216		4,194,006
Current liabilities	133,306		133,306		154,173
Long-term debt, including current portion	2,839,143		2,839,143		2,877,950
Total liabilities	3,549,520		3,549,520		3,597,056
Shareholders' equity/Members' equity (deficit)	367,696		367,696		596,950
XTAR, LLC [Member]
Statement of Operations Data:
Revenues	3,826	4,422	7,523	10,300
Operating expenses	(3,964)	(7,938)	(7,945)	(16,193)
Depreciation, amortization and stock-based compensation	(1,659)	(2,192)	(3,317)	(4,384)
Operating income (loss)	(1,797)	(5,708)	(3,739)	(10,277)
Net income (loss)	(3,429)	$ (6,511)	(6,702)	$ (12,039)
Current assets	5,567		5,567		6,364
Total assets	31,895		31,895		36,008
Current liabilities	57,331		57,331		53,795
Total liabilities	76,436		76,436		75,395
Shareholders' equity/Members' equity (deficit)	$ (44,541)		$ (44,541)		$ (39,387)