Summary Of Significant Accounting Policies (Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes		$ 523	$ (86)	$ 686	$ 156,513
Income tax expense		(234)	31	(201)	(85,741)
Net income (loss) from discontinued operations		289	(55)	485	70,772
Tax benefit (a)		(6,115)	(7,301)	(47,378)	(51,274)
Net income		13,043	10,471	84,779	160,034
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	0	0	(732)
Income tax expense	[1]	0	0	0	272
Net income (loss) from discontinued operations		0	0	0	(460)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	[1]	0	0	0	3
Other Comprehensive Loss Reclassification Adjustment From AOCI For Sale Of Securities Before Tax	[1]	0	0	0	(735)
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)	(172)	(1,133)	(516)
Tax benefit (a)		132	60	396	181
Net income		(246)	(112)	(737)	(335)
Amortization of net loss	[2]	273	37	819	113
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	[2]	(3,688)	(1,988)	(11,063)	(5,968)
Adjustment due to effects of regulation	[2]	$ 3,037	$ 1,779	$ 9,111	$ 5,339

[1] These amounts were included as part of net income from discontinued operations (see Note 4 for additional details).

[2] These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 7 for additional details).