Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets (Liabilities)
Lease and well equipment inventory	$ 877	$ 1,343
Fair value on a non-recurring basis [Member]
Assets (Liabilities)
Lease and well equipment inventory	34	1,343
Total	(1,209)	1,156
Fair value on a non-recurring basis [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations	(1,243)	(187)
Fair value on a non-recurring basis [Member] | Level 1 [Member]
Assets (Liabilities)
Lease and well equipment inventory
Total
Fair value on a non-recurring basis [Member] | Level 1 [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations
Fair value on a non-recurring basis [Member] | Level 2 [Member]
Assets (Liabilities)
Lease and well equipment inventory
Total
Fair value on a non-recurring basis [Member] | Level 2 [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations
Fair value on a non-recurring basis [Member] | Level 3 [Member]
Assets (Liabilities)
Lease and well equipment inventory	34	1,343
Total	(1,209)	1,156
Fair value on a non-recurring basis [Member] | Level 3 [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations	$ (1,243)	$ (187)