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CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS (Tables)
12 Months Ended
Dec. 31, 2019
CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS  
Schedule of total revenues from major customers

Year Ended December 31, 

 

    

Segment

    

2019

2018

2017

 

(in thousands)

Customer A

 

Illinois Basin

$

228,500

$

219,115

$

Customer B

Appalachia

213,319