Reportable Segments (Details)	6 Months Ended
	Jun. 30, 2016 item mi bbl
Crude oil pipelines and storage | Permian Basin
Reportable Segments
Length of high-pressure steel pipeline | mi	156
Throughput capacity per day | bbl	130,000
Storage capacity | bbl	140,000
Crude oil pipelines and storage | Cushing, Oklahoma
Reportable Segments
Storage capacity | bbl	3,000,000
Refined products terminals and storage
Reportable Segments
Storage capacity | bbl	1,300,000
Number of refined product terminals	2
Refined products terminals and storage | North Little Rock, Arkansas
Reportable Segments
Storage capacity | bbl	550,000
Number of storage tanks	11
Number of loading lanes	8
Refined products terminals and storage | Caddo Mills, Texas
Reportable Segments
Storage capacity | bbl	770,000
Number of storage tanks	10
Number of loading lanes	5
NGL distribution and sales
Reportable Segments
Number of businesses	3
Number of states covered by cylinder exchange network	46
Number of locations covering cylinder exchange network	20,000
Number of states in which product is sold to retailers, wholesalers, industrial end-users and commercial and residential customers.	7