Quarterly report pursuant to Section 13 or 15(d)

LEASES (Narrative) (Details)

v3.19.3.a.u2
LEASES (Narrative) (Details) - USD ($)
Sep. 30, 2019
Jan. 01, 2019
Dec. 31, 2018
Lessee, Lease, Description [Line Items]      
Operating lease assets $ 13,920,000    
Lease liability 62,369,000    
Accumulated deficit $ (1,032,972,000)   $ (845,368,000)
Weighted average remaining lease term 1 year 9 months 25 days    
Weighted-average discount rate - operating leases 3.66%    
Accounting Standards Update 2016-02      
Lessee, Lease, Description [Line Items]      
Operating lease assets   $ 110,000,000  
Lease liability   110,000,000  
Accumulated deficit   $ 0  
Minimum      
Lessee, Lease, Description [Line Items]      
Lease term 1 year    
Maximum      
Lessee, Lease, Description [Line Items]      
Lease term 5 years    
Drilling Rig | Minimum      
Lessee, Lease, Description [Line Items]      
Lease term 1 year    
Drilling Rig | Maximum      
Lessee, Lease, Description [Line Items]      
Lease term 2 years