CONSOLIDATED BALANCE SHEETS Parenthetical - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Other property and equipment, accumulated depreciation	$ 49,985,000	$ 42,882,000
Common Stock, par value per share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	111,687,016	111,257,500
Common Stock, Shares, Outstanding	111,687,016	111,257,500