BUSINESS SEGMENTS - Revenue by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue:
Total revenue	$ 922,619	$ 766,605	$ 2,702,093	$ 2,324,321
United States
Revenue:
Total revenue	855,795	683,850	2,474,562	2,072,893
International
Revenue:
Total revenue	66,824	82,755	227,531	251,428
Operating Segments | Domestic Pipelines & Terminals
Revenue:
Total revenue	254,277	265,036	761,438	752,968
Operating Segments | Global Marine Terminals
Revenue:
Total revenue	155,281	170,072	487,613	509,653
Operating Segments | Merchant Services
Revenue:
Total revenue	526,844	344,041	1,498,438	1,103,186
Intersegment
Revenue:
Total revenue	$ (13,783)	$ (12,544)	$ (45,396)	$ (41,486)