COSTS, EXPENSES, AND OTHER (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended		1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Feb. 29, 2012 Arbitration Decision member	Jun. 30, 2013 Arbitration Decision	Mar. 31, 2013 8 1/2% Senior Notes due 2014	Dec. 31, 2012 8 1/2% Senior Notes due 2014
Costs, expenses, and other
Accretion of asset retirement obligations	$ 549,000	$ 1,597,000	$ 1,793,000	$ 3,195,000
Loss on debt extinguishment	0	0	25,223,000	0			25,223,000
Legal proceeding liabilities	0	0	0	22,847,000	22,847,000
Other, net	1,044,000	1,858,000	3,397,000	4,333,000
Costs, expenses and other	1,593,000	3,455,000	30,413,000	30,375,000
Redeemed Principal Amount of Senior Notes							300,000,000
Redemption Price As Percentage Of Par (as a percent)							107.11%
Call premium on early redemption of notes							21,300,000
Write-off of debt issuance costs and unamortized discount							3,900,000
Interest rate (as a percent)							8.50%	8.50%
Number of members of arbitration panel reaching an adverse decision to Company (in members)					2
Total number of members on arbitration panel (in members)					3
Liability from arbitration decision						$ 23,600,000