Segment Information (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Reportable segments	2		2
Other Revenue, Net	$ 14.7	$ 12.2	$ 40.4	$ 37.1
SLC Pipeline [Member]
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%
UNEV Pipeline [Member]
Segment Reporting Information [Line Items]
Percentage of interest owned in pipeline project	75.00%