CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 81,260	$ 117,092
Other comprehensive income (loss):
Unrealized gains on derivative instruments, net	101	14,138
Reclassification of derivative losses to net income, net	2,296	2,337
Changes in benefit plan assets and benefit obligations	(755)	18
Other comprehensive income from equity method investments	0	13,963
Total other comprehensive income	1,642	30,456
Comprehensive income	82,902	147,548
Less: Comprehensive income attributable to noncontrolling interests	(498)	(4,719)
Comprehensive income attributable to Buckeye Partners, L.P.	$ 82,404	$ 142,829