EARNINGS PER UNIT (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income attributable to Buckeye Partners, L.P.	$ 116,187	$ 156,374	$ 352,485	$ 427,943
Basic:
Weighted average units outstanding - basic (in shares)	142,088	131,113	141,104	130,439
Earnings per unit - basic (in dollars per share)	$ 0.82	$ 1.19	$ 2.50	$ 3.28
Diluted:
Weighted average units outstanding - basic (in shares)	142,088	131,113	141,104	130,439
Dilutive effect of LP Unit options and LTIP awards granted (in shares)	730	827	677	637
Weighted average units outstanding - diluted (in shares)	142,818	131,940	141,781	131,076
Earnings per unit - diluted (in dollars per share)	$ 0.81	$ 1.19	$ 2.49	$ 3.26