Derivatives and Risk Management Activities (Details)	Mar. 31, 2014 bbl
Net long position associated with crude oil purchases
Commodity Price Risk Hedging:
Average derivative positions notional amount per day (in barrels)	272,000
Derivative position notional amount (in barrels, Mcf or megawatt hours)	8,200,000
Net short spread position hedging anticipated crude oil lease gathering purchases
Commodity Price Risk Hedging:
Average derivative positions notional amount per day (in barrels)	24,700
Derivative position notional amount (in barrels, Mcf or megawatt hours)	9,800,000
Butane/WTI spread positions
Commodity Price Risk Hedging:
Average derivative positions notional amount per day (in barrels)	2,900
Derivative position notional amount (in barrels, Mcf or megawatt hours)	1,100,000
Brent/WTI spread positions
Commodity Price Risk Hedging:
Average derivative positions notional amount per day (in barrels)	19,000
Derivative position notional amount (in barrels, Mcf or megawatt hours)	1,200,000
Long natural gas position for anticipated base gas requirements
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	2,100,000
Short natural gas position related to anticipated natural gas sales
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	12,600,000
Net short position related to anticipated sales of crude oil, NGL and refined products inventory
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	5,000,000
Positions hedging risk of not utilizing storage capacity
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	500,000
PLA crude oil net short position
Commodity Price Risk Hedging:
Average derivative positions notional amount per day (in barrels)	1,800
Derivative position notional amount (in barrels, Mcf or megawatt hours)	1,100,000
PLA Crude oil long call option position
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	400,000
Long natural gas position for natural gas purchases
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	21,800,000
Short propane position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	3,800,000
Short Butane position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	1,200,000
Short WTI position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	400,000
Long power position for power supply requirements
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, Mcf or megawatt hours)	700,000