Summary Of Significant Accounting Policies (Other Income - Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Interest income	$ 1,823	$ 653	$ 987
Interest on regulatory deferrals	1,308	48	220
Equity-related AFUDC	8,475	8,331	8,808
Net gain (loss) on investments	(2,152)	(637)	276
Other income	624	905	1,055
Other income-net	$ 10,078	$ 9,300	$ 11,346