Equity In Net Income (Losses) of Affiliates (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Investments In Affiliates [Line Items]
Equity in net income of affiliates	$ 41,586	$ (77,262)	$ 37,102	$ (7,076)
Telesat Holdings Inc [Member]
Investments In Affiliates [Line Items]
Equity in net income of affiliates	43,654	(75,044)	42,179	(963)
XTAR, LLC [Member]
Investments In Affiliates [Line Items]
Equity in net income of affiliates	(2,068)	(2,195)	(5,077)	(6,048)
Other [Member]
Investments In Affiliates [Line Items]
Equity in net income of affiliates		$ (23)		$ (65)