Annual report pursuant to Section 13 and 15(d)

EQUITY CAPITALIZATION (Details)

v3.10.0.1
EQUITY CAPITALIZATION (Details)
$ / shares in Units, $ in Thousands
12 Months Ended
Nov. 09, 2017
$ / shares
shares
Mar. 22, 2017
USD ($)
$ / shares
shares
Dec. 27, 2016
USD ($)
$ / shares
shares
Jun. 08, 2016
USD ($)
shares
Dec. 31, 2018
USD ($)
$ / shares
shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
shares
Sep. 30, 2013
$ / shares
Subsidiary, Sale of Stock [Line Items]                
Proceeds from additional common equity capitalization | $         $ 0 $ 0 $ 40,425  
Proceeds from preferred equity capitalization | $     $ 170,000   $ 0 $ 0 170,000  
Preferred stock, par value (in dollars per share) | $ / shares         $ 0.001 $ 0.001    
Payment of IPO costs | $         $ 0 $ 0 $ 7,489  
Preferred stock, issued (in shares) | shares         0 0    
Preferred stock, outstanding (in shares) | shares         0 0 16,999,990  
Common stock, par value (in dollars per share) | $ / shares         $ 0.001 $ 0.001   $ 0.001
Proceeds from IPO | $         $ 0 $ 185,500 $ 0  
Repayment of outstanding borrowings | $   $ 71,800     80,946 166,546 41,295  
Capital expenditures | $   $ 86,800     $ 284,197 $ 285,891 $ 42,832  
Exercised (in shares) | shares         49,912      
Common stock, outstanding (in shares) | shares         100,190,126 83,039,854    
Private Placement                
Subsidiary, Sale of Stock [Line Items]                
Shares of common stock sold, including shares sold by third parties (in shares) | shares     16,999,990          
Preferred stock, par value (in dollars per share) | $ / shares     $ 0.001          
Payment of IPO costs | $     $ 7,000          
Preferred equity capitalization, net of costs | $     $ 163,000          
IPO                
Subsidiary, Sale of Stock [Line Items]                
Shares of common stock sold, including shares sold by third parties (in shares) | shares   25,000,000            
Common stock, par value (in dollars per share) | $ / shares   $ 0.001            
Stock price (in dollars per share) | $ / shares   $ 14.00            
Proceeds from IPO | $   $ 170,100            
Payment of underwriting discounts and commissions | $   10,900            
Payments of stock issuance costs, other | $   $ 4,500            
IPO Sold By Company                
Subsidiary, Sale of Stock [Line Items]                
Shares of common stock sold, including shares sold by third parties (in shares) | shares   13,250,000            
IPO sold by existing stockholders                
Subsidiary, Sale of Stock [Line Items]                
Shares of common stock sold, including shares sold by third parties (in shares) | shares   11,750,000            
Series A convertible preferred stock                
Subsidiary, Sale of Stock [Line Items]                
Preferred stock, issued (in shares) | shares             16,999,990  
Performance stock units | IPO                
Subsidiary, Sale of Stock [Line Items]                
Number of shares of outstanding stock converted (in shares) | shares   16,999,990            
Series A Preferred Stock Converted To Common Stock | IPO                
Subsidiary, Sale of Stock [Line Items]                
Shares of common stock issued for each share of preferred stock converted   1            
Energy Capital Partners Affiliates                
Subsidiary, Sale of Stock [Line Items]                
Issuance of common stock (in shares) | shares 13,800,000              
Shares issued, price per share (in dollars per share) | $ / shares $ 15.07              
Energy Capital Partners Affiliates                
Subsidiary, Sale of Stock [Line Items]                
Proceeds from additional common equity capitalization | $       $ 40,400        
Issuance of common stock (in shares) | shares       18,007,328