Discontinued Operations Discontinued Operations (Statements of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
OIL AND GAS REVENUES	$ 0	$ 0
General and administrative	5	2
Accretion related to asset retirement obligations	36	76
TOTAL COST AND EXPENSES	41	78
OPERATING LOSS	(41)	(78)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	37,294	0
Gain (loss) on derivative instruments, net	(44)	(765)
Interest expense	(253)	(879)
Capitalized interest	253	0
Other income (expense), net	24	(798)
LOSS BEFORE INCOME TAXES	37,233	(2,520)
INCOME TAX (EXPENSE) BENEFIT	(13,575)	1,267
NET INCOME (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	$ 23,658	$ (1,253)