Quarterly report pursuant to Section 13 or 15(d)

COMMITMENTS & CONTINGENCIES - Litigation (Details)

v3.8.0.1
COMMITMENTS & CONTINGENCIES - Litigation (Details)
$ in Millions
3 Months Ended
Mar. 31, 2018
USD ($)
plaintiff
Other Noncurrent Assets, Net  
Loss Contingencies [Line Items]  
Loss contingency accounts receivable | $ $ 5.4
Quiet title action in North Dakota  
Loss Contingencies [Line Items]  
Loss contingency, number of plaintiffs | plaintiff 4