Partnership Operations, Organization and Basis for Presentation (Details) bbl in Millions, $ in Millions, ft³ in Billions	3 Months Ended
	Mar. 31, 2016 Segment mi bbl ft³	Dec. 31, 2015 USD ($)	Dec. 31, 2014
Related Party Transaction [Line Items]
Number of miles of pipelines | mi	49,000
Number of barrels of storage capacity | bbl	250
Number of cubic feet of storage capacity | ft³	14
Number of reportable segments | Segment	5
Limited partners ownership interest (in hundredths)	100.00%
Debt Instrument [Line Items]
Unamortized debt issuance costs in current assets		$ 14.7
Unamortized debt issuance costs in other assets		135.1
Total unamortized debt issuance costs		$ 149.8
EPCO and its privately held affiliates [Member]
Related Party Transaction [Line Items]
Percentage of Total Units Outstanding (in hundredths)	33.30%
Oiltanking Partners L.P. [Member]
Business Acquisition [Line Items]
Limited partner interests acquired (in hundredths)			65.90%