Comprehensive Income (Accumulated Other Comprehensive Loss, Net of Tax) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	$ (260,530)	$ (483,576)
Other comprehensive income before reclassifications	148	(359)
Amounts reclassified from accumulated other comprehensive loss	8,241	20,164
Recognition of net actuarial loss for pension settlement costs		24,992
Net current-period other comprehensive income (loss)	8,389	44,797
Balance, ending	(252,141)	(438,779)
Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(411,432)	(697,874)
Other comprehensive income before reclassifications		133
Amounts reclassified from accumulated other comprehensive loss	14,069	30,948
Recognition of net actuarial loss for pension settlement costs		40,309
Net current-period other comprehensive income (loss)	14,069	71,390
Balance, ending	(397,363)	(626,484)
Postretirement Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(5,230)	(74,264)
Other comprehensive income before reclassifications		(267)
Amounts reclassified from accumulated other comprehensive loss	(777)	1,575
Net current-period other comprehensive income (loss)	(777)	1,308
Balance, ending	(6,007)	(72,956)
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		(227)
Amounts reclassified from accumulated other comprehensive loss	(5,051)	(12,359)
Recognition of net actuarial loss for pension settlement costs		(15,317)
Net current-period other comprehensive income (loss)	(5,051)	(27,903)
Balance, ending	151,229	260,809
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)