Summary Of Significant Accounting Policies (Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes			$ 2,409
Income tax expense			(894)
Net income from discontinued operations	0		1,515
Tax expense (a)	(26,247)		(27,282)
Net income	46,462		48,981
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes	0		3
Income tax expense	0		(1)
Net income from discontinued operations	0		2
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	0		3
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(378)		(170)
Tax expense (a)	132		59
Net income	(246)		(111)
Amortization of net loss	273	[1]	38	[1]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	(3,688)	[1]	(1,990)	[1]
Adjustment due to effects of regulation	$ 3,037	[1]	$ 1,782	[1]

[1] These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 6 for additional details).