Derivatives and Risk Management Activities (Details)	Jun. 30, 2012 barrel barrelspermonth
Commodity Price Risk Hedging:
Storage capacity owned but not used in entity's transportation operations (in barrels)	100,000,000
Derivative hedges to manage the risk of not utilizing storage capacity (in barrels per month)	1,600,000
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	12,200,000
Net long crude oil derivative position
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	245,700
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	7,600,000
Net short spread position hedging anticipated crude oil lease gathering purchases
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	26,200
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	10,400,000
WTS/WTI crude oil basis swaps
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	8,300
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	4,600,000
LLS/WTI crude oil basis swaps
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	7,900
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	1,200,000
Average butane/WTI spread positions
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	2,400
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	900,000
Crude oil net short position
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	1,400
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	1,800,000
Long natural gas swaps position for natural gas purchases
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	16.7
Short propane contracts position related to subsequent sale of products
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	2,800,000
Short Butane contracts position related to subsequent sale of products
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	800,000
Short WTI contracts position related to subsequent sale of products
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	300,000
Crude oil long put option position
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	100,000
Crude oil long call option position
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	900,000
Long natural gas swaps position for anticipated base gas purchases
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	4.1
Short natural gas swap position related to anticipated natural gas sales
Commodity Price Risk Hedging:
Crude oil, NGL, refined products or natural gas inventory hedged (in barrels or bcf)	23.4