CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Restricted investments in U.S. Treasury bonds-available for sale, amortized cost (in dollars)	$ 94	$ 89
Oil and gas properties, unproved properties excluded from amortization (in dollars)	20,507	22,963
Restricted investments in U.S. Treasury bonds-available for sale, amortized cost (in dollars)	849	804
8% convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
8% convertible preferred stock, authorized shares	10,000,000	10,000,000
8% convertible preferred stock, issued shares	10,703	10,703
8% convertible preferred stock, outstanding shares	10,703	10,703
8% convertible preferred stock, aggregate liquidation preference (in dollars)	128	128
Preferred stock dividend rate (as a percent)	8.00%	8.00%
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	72,440,898	71,518,810
Accumulated other comprehensive income, applicable income taxes (in dollars)	$ 188	$ 181
Common stock in Treasury, shares	632,250	632,250