Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Postretirement Benefits [Member]	Dec. 31, 2013 Postretirement Benefits [Member]	Sep. 30, 2014 Proportionate Share of Telesat Other Comprehensive Loss [Member]	Dec. 31, 2013 Proportionate Share of Telesat Other Comprehensive Loss [Member]	Sep. 30, 2014 Accumulated Other Comprehensive Loss [Member]	Dec. 31, 2013 Accumulated Other Comprehensive Loss [Member]
Accumulated other comprehensive income (loss), beginning balance			$ (20,916)		$ (9,171)	$ (17,653)	$ (11,745)	$ (19,741)	$ (20,916)	$ (37,394)
Other comprehensive income (loss) before reclassification						3,102	2,382	7,996	2,382	11,098
Amounts reclassified from accumulated other comprehensive income (loss)					210	5,380			210	5,380
Net current-period other comprehensive income (loss)	1,543	526	2,592	2,389	210	8,482	2,382	7,996	2,592	16,478
Accumulated other comprehensive income (loss), ending balance	$ (18,324)		$ (18,324)		$ (8,961)	$ (9,171)	$ (9,363)	$ (11,745)	$ (18,324)	$ (20,916)