DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Commodity Derivative Instruments (Details) gal in Thousands	9 Months Ended
	Sep. 30, 2016 gal
Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts | Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	8,504
Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts | Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	1,073
Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts | Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	31,274
Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts | Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	0
Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products | Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	24,819
Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products | Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	16,926
Derivatives Designated as Hedging Instruments | Fair Value Hedge | Physical fixed price derivative contracts | Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	1,176
Derivatives Designated as Hedging Instruments | Fair Value Hedge | Physical fixed price derivative contracts | Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	0
Derivatives Designated as Hedging Instruments | Fair Value Hedge | Futures contracts for refined petroleum products | Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	163,800
Derivatives Designated as Hedging Instruments | Fair Value Hedge | Futures contracts for refined petroleum products | Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	0