DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Commodity Derivative Instruments (Details) gal in Thousands	9 Months Ended
	Sep. 30, 2019 gal
Derivatives NOT Designated as Hedging Instruments \| Physical fixed-price derivative contracts \| Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	14,544
Derivatives NOT Designated as Hedging Instruments \| Physical fixed-price derivative contracts \| Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	879
Derivatives NOT Designated as Hedging Instruments \| Physical index derivative contracts \| Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	677
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)	26,622
Derivatives NOT Designated as Hedging Instruments \| Futures contracts for refined petroleum products \| Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	1,638
Derivatives Designated as Hedging Instruments \| Cash Flow Hedge \| Physical index derivative contracts \| Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	2,946
Derivatives Designated as Hedging Instruments \| Cash Flow Hedge \| Physical index derivative contracts \| Long-Term
Derivative Instruments And Hedging Activities
Volume (in gallons)	0
Derivatives Designated as Hedging Instruments \| Cash Flow Hedge \| Cash flow hedge futures contracts \| Current
Derivative Instruments And Hedging Activities
Volume (in gallons)	29,652
Derivatives Designated as Hedging Instruments \| Cash Flow Hedge \| Cash flow hedge futures 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)	50,568
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

BUCKEYE PARTNERS, L.P. 10-Q