Derivatives and Risk Management Activities (Details)	Mar. 31, 2012 barrel
Commodity Price Risk Hedging:
Storage capacity owned but not used in entity's transportation operations (in barrels)	78,000,000
Crude oil, LPG and refined products inventory hedged (in barrels)	7,500,000
Net long crude oil derivative position
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	217,100
Crude oil, LPG and refined products inventory hedged (in barrels)	6,500,000
Net short spread position hedging anticipated crude oil lease gathering purchases
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	21,400
Crude oil, LPG and refined products inventory hedged (in barrels)	19,600,000
WTS/WTI crude oil basis swaps
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	9,000
Crude oil, LPG and refined products inventory hedged (in barrels)	5,800,000
LLS/WTI crude oil basis swaps
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	10,500
Crude oil, LPG and refined products inventory hedged (in barrels)	2,600,000
Average butane/WTI spread positions
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	16,200
Crude oil, LPG and refined products inventory hedged (in barrels)	1,500,000
Crude oil net short position
Commodity Price Risk Hedging:
Net derivative positions per day (in barrels)	1,500
Crude oil, LPG and refined products inventory hedged (in barrels)	2,100,000
Crude oil long put option position
Commodity Price Risk Hedging:
Crude oil, LPG and refined products inventory hedged (in barrels)	200,000
Crude oil long call option position
Commodity Price Risk Hedging:
Crude oil, LPG and refined products inventory hedged (in barrels)	600,000
Long natural gas swaps position for anticipated base gas purchases
Commodity Price Risk Hedging:
Crude oil, LPG and refined products inventory hedged (in barrels)	3.5
Short natural gas swap position related to anticipated natural gas sales
Commodity Price Risk Hedging:
Crude oil, LPG and refined products inventory hedged (in barrels)	21.9

Derivatives and Risk Management Activities (Details)

Mar. 31, 2012

barrel

Commodity Price Risk Hedging:

Storage capacity owned but not used in entity's transportation operations (in barrels)

78,000,000

Crude oil, LPG and refined products inventory hedged (in barrels)

7,500,000

Net long crude oil derivative position

Commodity Price Risk Hedging:

Net derivative positions per day (in barrels)

217,100