Business Segments (Details)	12 Months Ended
	Dec. 31, 2018 Segment Fractionator mi
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	4
Number of miles of pipelines	49,200
NGL Pipelines and Services [Member]
Segment Reporting Information [Line Items]
Number of miles of pipelines	19,200
Number of fractionators | Fractionator	16
Crude Oil Pipelines & Services [Member]
Segment Reporting Information [Line Items]
Number of miles of pipelines	5,300
Natural Gas Pipelines & Services [Member]
Segment Reporting Information [Line Items]
Number of miles of pipelines	19,700
Petrochemical and Refined Products Services [Member] | Propylene Operations [Member]
Segment Reporting Information [Line Items]
Number of miles of pipelines	800
Petrochemical and Refined Products Services [Member] | Refined Products Operations [Member]
Segment Reporting Information [Line Items]
Number of miles of pipelines	4,100