Quarterly report pursuant to Section 13 or 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.19.1
RELATED PARTY TRANSACTIONS (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2018
Jan. 31, 2019
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Related Party Transaction [Line Items]          
Stock repurchased (in shares)     5,635,000 0 7,360,000
Stock repurchased, value     $ 16,300    
W Energy Partners LLC | Common Stock          
Related Party Transaction [Line Items]          
Stock repurchased (in shares)   3,700,000      
Stock repurchased, value   $ 11,100      
Subscription Arrangement          
Related Party Transaction [Line Items]          
Sale of stock, percentage of ownership before transaction (in excess) (percent) 5.00%