CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 90,515	$ 93,317	$ 171,775	$ 210,409
Other comprehensive income (loss):
Unrealized (losses) gains on derivative instruments, net	(823)	8,936	(722)	23,074
Reclassification of derivative losses to net income, net	2,296	2,295	4,592	4,632
Changes in benefit plan assets and benefit obligations	(66)	(18)	(821)	0
Other comprehensive loss from equity method investments	0	(21,720)	0	(7,757)
Total other comprehensive income (loss)	1,407	(10,507)	3,049	19,949
Comprehensive income	91,922	82,810	174,824	230,358
Less: Comprehensive income attributable to noncontrolling interests	(496)	(1,413)	(994)	(6,132)
Comprehensive income attributable to Buckeye Partners, L.P.	$ 91,426	$ 81,397	$ 173,830	$ 224,226