Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets
Oil and gas properties, successful efforts method of accounting, accumulated depletion (in dollars)	$ 0	$ 0
Other property and equipment, accumulated depreciation and amortization (in dollars)	$ 2,992	$ 2,533
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares issued	406,707,716	406,596,884
Common stock, shares outstanding	406,707,716	406,596,884