Investments in Affiliates (Narrative) (Details) CAD in Millions	3 Months Ended						12 Months Ended
	Mar. 31, 2016 CAD item shares	Mar. 31, 2016 USD ($) item shares	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2009 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates		$ 60,942,000
Equity method OCI previously suspended recovered		$ 20,800,000
Telesat Holdings Inc [Member]
Investments in and Advances to Affiliates [Line Items]
Economic interest in affiliates		62.70%	62.80%				62.80%
Voting interest in affiliate		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
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		$ 60,942,000	0				0
Equity method losses previously suspended recovered		57,900,000
Total assets		4,237,073,000	3,991,301,000				3,991,301,000
Long-term debt, including current portion		2,955,865,000	2,950,726,000				2,950,726,000
Capital expenditures		69,200,000			$ 21,000,000
XTAR, LLC [Member]
Investments in and Advances to Affiliates [Line Items]
Investments in affiliates		0	0				0
Total assets		$ 42,641,000	44,793,000				$ 44,793,000
Percentage of ownership interest		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
Maximum annual lease obligation		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		$ 23,800,000	17,700,000				$ 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%
Interest expense multiplier to determine EBITDA available for dividend distribution | item	1.40	1.40
Management [Member] | Telesat Holdings Inc [Member]
Investments in and Advances to Affiliates [Line Items]
Equity method investee, stock options buy back, amount | CAD	CAD 18.7
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)