FAIR VALUE MEASUREMENTS (Details 3) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Proved Oil and Gas Properties
Estimated discount rate to measure fair value of proved oil and gas properties (as a percent)	10.00%
Proved properties	$ 1,576,118,000	$ 1,257,288,000
Unproved properties	14,654,000	45,081,000
Asset retirement obligations	11,273,000	11,050,000
6.75% Senior Notes
Proved Oil and Gas Properties
Outstanding amount	500,000,000
Long-term debt	508,200,000	508,800,000
Interest rate (as a percent)	6.75%
Fair Value
Proved Oil and Gas Properties
Proved properties	0	0
Unproved properties	0	0
Asset retirement obligations	0	0
Fair value of Senior Notes	$ 537,500,000	$ 527,500,000