Investments in Affiliates (Narrative) (Details) $ / shares in Units, CAD in Millions	3 Months Ended							6 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 CAD shares	Mar. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2009 USD ($)	Jun. 30, 2016 USD ($) item	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	$ 104,793,000							$ 104,793,000
Equity method OCI previously suspended recovered			$ 20,800,000
Equity in net income (loss) of affiliates	43,357,000					$ 25,087,000		89,851,000	$ (51,758,000)
Net income (loss)	$ 32,552,000					17,800,000		$ 63,238,000	(64,842,000)
Telesat Holdings Inc [Member]
Investments in and Advances to Affiliates [Line Items]
Economic interest in affiliates	62.70%			62.80%				62.70%		62.80%
Voting interest in affiliate	32.70%							32.70%
Share appreciation rights exercised by Telesat employees | shares		178,642	178,642
Non-voting participating preferred stock issued to Telesat Employees | shares		129,400	129,400
Equity method investee, stock options buy back, shares | shares		1,253,477	1,253,477
Equity method investee, stock options buy back, amount | CAD		CAD 24.7
Equity method investment unrecognized loss in equity				$ 57,900,000						$ 57,900,000
Equity method investment unrecognized gain in other comprehensive income										20,800,000
Investments in affiliates	$ 104,793,000			0				$ 104,793,000		0
Equity method losses previously suspended recovered			$ 57,900,000
Equity in net income (loss) of affiliates	43,357,000					27,913,000		89,851,000	(46,416,000)
Total assets	4,281,263,000			3,991,301,000				4,281,263,000		3,991,301,000
Long-term debt, including current portion	2,940,515,000			2,950,726,000				2,940,515,000		2,950,726,000
Capital expenditures								105,000,000	50,900,000
Telesat Holdings Inc [Member] | Management [Member]
Investments in and Advances to Affiliates [Line Items]
Equity method investee, stock options buy back, amount | CAD		CAD 18.7
XTAR, LLC [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates	0			0				0		0
Equity in net income (loss) of affiliates						$ (2,826,000)			$ (5,342,000)
Total assets	$ 39,638,000			44,793,000				$ 39,638,000		$ 44,793,000
Percentage of ownership interest	56.00%							56.00%
Equity method investment, impairment				13,200,000	$ 8,000,000
Equity method investee, percentage of decline in revenue over previous year										11.00%
Lease obligation	$ 26,000,000							$ 26,000,000
Maximum annual lease obligation	28,000,000							28,000,000
Lease agreement, past due												$ 32,300,000
Lease agreement, deferred amount											$ 6,700,000
Repayment term past due and deferred lease obligation, years							12 years
Deferred lease obligation, annual payment							$ 5,000,000
Discount rate for prepayment of restructured past due and deferred lease obligation							9.00%
Cumulative payments of restructured past due and deferred lease obligation								29,200,000
Equity method investment, investee past due liability	$ 28,000,000			17,700,000				$ 28,000,000		$ 17,700,000
6% Senior Notes Due May 2017 [Member] | Telesat Holdings Inc [Member]
Investments in and Advances to Affiliates [Line Items]
Interest on notes	6.00%							6.00%
Interest expense multiplier to determine EBITDA available for dividend distribution | item								1.40
Adjustments for New Accounting Pronouncement [Member] | Telesat Holdings Inc [Member]
Investments in and Advances to Affiliates [Line Items]
Total assets				(18,100,000)						(18,100,000)
Long-term debt, including current portion				$ (18,100,000)						$ (18,100,000)
Overstatement [Member] | Restatement Adjustment [Member]
Investments in and Advances to Affiliates [Line Items]
Equity in net income (loss) of affiliates	$ 5,100,000
Net income (loss)	$ 3,200,000
Earnings per share, basic and diluted | $ / shares	$ 0.10