CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (51,915)	$ 493,665	$ 548,675
Other comprehensive (loss) income:
Unrealized gains (losses) on derivative instruments, net	29,714	(10,733)	60,281
Reclassification of derivative (gains) and losses to net income, net	(50,509)	11,922	10,884
Changes in benefit plan assets and benefit obligations	1,745	3,393	1,083
Other comprehensive (loss) income from equity method investments	(49,642)	49,642	0
Total other comprehensive (loss) income	(68,692)	54,224	72,248
Comprehensive (loss) income	(120,607)	547,889	620,923
Less: Comprehensive income attributable to noncontrolling interests	(7,123)	(14,863)	(13,067)
Comprehensive (loss) income attributable to Buckeye Partners, L.P.	$ (127,730)	$ 533,026	$ 607,856