Business Combinations and Asset Acquisitions (Narrative) (Details) bbl in Millions	1 Months Ended			12 Months Ended
	Nov. 30, 2014 USD ($) bbl mi	Nov. 30, 2013 USD ($) Terminal bbl mi	Jul. 31, 2013 USD ($) mi	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Business Combination and Asset Acquisition [Line Items]
Acquisition of business				$ 54,678,000	$ 0	$ 192,000,000
Debt Instrument, Face Amount				3,400,000,000.0	2,900,000,000.0
Payments to Acquire Other Productive Assets				0	$ 75,000,000	22,506,000
Atlanta, Georgia Terminal [Member]
Business Combination and Asset Acquisition [Line Items]
Acquisition of business				$ 54,700,000
Plains Pipeline Acquisition [Member]
Business Combination and Asset Acquisition [Line Items]
Business Acquisition, Transaction Costs						$ 2,800,000
BridgeTex 40-Mile Pipeline [Member]
Business Combination and Asset Acquisition [Line Items]
Pipeline, Length | mi	40
Storage Capacity | bbl	1.4
Payments to Acquire Other Productive Assets	$ 75,000,000
Acquisition of Assets Ownership Percentage	100.00%
New Mexico/Texas [Member] | Plains Pipeline Acquisition [Member]
Business Combination and Asset Acquisition [Line Items]
Acquisition of business			$ 57,000,000
Pipeline, Length | mi			250
Rocky Mountains [Member] | Plains Pipeline Acquisition [Member]
Business Combination and Asset Acquisition [Line Items]
Acquisition of business		$ 135,000,000
Pipeline, Length | mi		550
Number of Pipeline Terminals | Terminal		4
Storage Capacity | bbl		1.7
Debt Offering Part One [Member] | Five Point One Five Percentage Notes Due Two Thousand Forty Three [Member]
Business Combination and Asset Acquisition [Line Items]
Debt Instrument, Face Amount		$ 300,000,000.0