Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated other comprehensive income (loss), Beginning balance	$ (37,394)	$ (154,475)	$ (95,873)
Other comprehensive income (loss) before reclassification	11,098	2,446	(69,845)
Amounts reclassified from accumulated other comprehensive income (loss)	5,380	114,635	11,243
Net current-period other comprehensive income (loss)	16,478	117,081	(58,602)
Accumulated other comprehensive income (loss), Ending balance	(20,916)	(37,394)	(154,475)
Selling General And Administrative Expense	16,038	28,774	18,345
Income tax (provision) benefit	(1,841)	93,315	(41,375)
Derivatives [Member]
Accumulated other comprehensive income (loss), Beginning balance		(1,306)	(6,753)
Other comprehensive income (loss) before reclassification		(415)	(5,272)
Amounts reclassified from accumulated other comprehensive income (loss)		1,721	10,719
Net current-period other comprehensive income (loss)		1,306	5,447
Accumulated other comprehensive income (loss), Ending balance			(1,306)
Unrealized Gains (losses) on Investments [Member]
Accumulated other comprehensive income (loss), Beginning balance		580	1,115
Other comprehensive income (loss) before reclassification		(120)	(535)
Amounts reclassified from accumulated other comprehensive income (loss)		(460)
Net current-period other comprehensive income (loss)		(580)	(535)
Accumulated other comprehensive income (loss), Ending balance			580
Postretirement Benefits [Member]
Accumulated other comprehensive income (loss), Beginning balance	(17,653)	(132,695)	(82,047)
Other comprehensive income (loss) before reclassification	3,102	1,668	(51,172)
Amounts reclassified from accumulated other comprehensive income (loss)	5,380	113,374	524
Net current-period other comprehensive income (loss)	8,482	115,042	(50,648)
Accumulated other comprehensive income (loss), Ending balance	(9,171)	(17,653)	(132,695)
Proportionate Share of Telesat Other Comprehensive Loss [Member]
Accumulated other comprehensive income (loss), Beginning balance	(19,741)	(21,054)	(8,188)
Other comprehensive income (loss) before reclassification	7,996	1,313	(12,866)
Net current-period other comprehensive income (loss)	7,996	1,313	(12,866)
Accumulated other comprehensive income (loss), Ending balance	(11,745)	(19,741)	(21,054)
Accumulated Other Comprehensive Loss [Member]
Net current-period other comprehensive income (loss)	16,478	117,081	(58,602)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Selling General And Administrative Expense	8,700
Income tax (provision) benefit	$ 3,300