Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets (Liabilities)
Lease and well equipment inventory	$ 966	$ 877
Fair value on a non-recurring basis [Member]
Assets (Liabilities)
Lease and well equipment inventory		34
Total	(656)	(1,209)
Fair value on a non-recurring basis [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations	(656)	(1,243)
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
Total	(656)	(1,209)
Fair value on a non-recurring basis [Member] | Level 3 [Member] | Asset retirement obligations [Member]
Assets (Liabilities)
Asset retirement obligations	$ (656)	$ (1,243)