Summary Of Significant Accounting Policies (Other Income - Net) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Accounting Policies [Abstract]
Interest income	$ (238)		$ (363)		$ (496)		$ (638)
Interest on regulatory deferrals	(8)		(16)		(21)		(24)
Equity-related AFUDC	(1,355)		(905)		(2,746)		(1,748)
Net loss on investments	(154)		88		244		527
Other income	(681)		(405)		(1,562)		(1,427)
Total	$ (2,436)	[1]	$ (1,601)	[1]	$ (4,581)	[1]	$ (3,310)	[1]

[1] The 2012 amount includes a correction of an immaterial error related to the reclassification of certain operating expenses from other expense-net to utility and non-utility other operating expenses and utility taxes other than income taxes. This correction did not have an impact on net income or earnings per share. See further discussion of this reclassification below under "Correction of an Immaterial Error."