Comprehensive Income (Accumulated Other Comprehensive Loss, Net of Tax) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	$ (260,530)	$ (483,576)
Other comprehensive income before reclassifications	148	128
Amounts reclassified from accumulated other comprehensive loss	5,781	13,364
Net current-period other comprehensive income (loss)	5,929	13,492
Balance, ending	(254,601)	(470,084)
Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(411,432)	(697,874)
Other comprehensive income before reclassifications		(230)
Amounts reclassified from accumulated other comprehensive loss	9,660	20,148
Net current-period other comprehensive income (loss)	9,660	19,918
Balance, ending	(401,772)	(677,956)
Postretirement Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(5,230)	(74,264)
Amounts reclassified from accumulated other comprehensive loss	(336)	1,406
Net current-period other comprehensive income (loss)	(336)	1,406
Balance, ending	(5,566)	(72,858)
Deferred Taxes On Pension And OPEB Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	156,280	288,712
Other comprehensive income before reclassifications		356
Amounts reclassified from accumulated other comprehensive loss	(3,543)	(8,190)
Net current-period other comprehensive income (loss)	(3,543)	(7,834)
Balance, ending	152,737	280,878
All Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(148)	(150)
Other comprehensive income before reclassifications	148	2
Amounts reclassified from accumulated other comprehensive loss
Net current-period other comprehensive income (loss)	148	2
Balance, ending		$ (148)