v3.20.4

SEGMENT INFORMATION Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue, Major Customer [Line Items]
Revenues	$ 1,481,564	$ 1,498,021	$ 1,520,262
Revenue Benchmark [Member] | Valero Energy Corporation [Member]
Revenue, Major Customer [Line Items]
Largest customer percentage of revenue	20.00%	21.00%	20.00%
Revenues	$ 295,100	$ 307,200	$ 303,700

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