CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Other property and equipment, accumulated depreciation	$ 24,091	$ 21,748
Other assets, accumulated depreciation and amortization	$ 8,478	$ 5,768
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	54,884,542	48,750,533
Treasury stock, shares	16,582	16,582