Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets (Liabilities)
Oil, natural gas and NGL derivatives	$ (11,096)
Fair value on a recurring basis [Member]
Assets (Liabilities)
Total	(11,096)	(2,753)
Fair value on a recurring basis [Member] | Natural Gas [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	193	192
Fair value on a recurring basis [Member] | Oil [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	(11,289)	(2,945)
Fair value on a recurring basis [Member] | Level 1 [Member]
Assets (Liabilities)
Total
Fair value on a recurring basis [Member] | Level 1 [Member] | Natural Gas [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	0	0
Fair value on a recurring basis [Member] | Level 1 [Member] | Oil [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	0	0
Fair value on a recurring basis [Member] | Level 2 [Member]
Assets (Liabilities)
Total	(11,096)	(2,753)
Fair value on a recurring basis [Member] | Level 2 [Member] | Natural Gas [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	193	192
Fair value on a recurring basis [Member] | Level 2 [Member] | Oil [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	(11,289)	(2,945)
Fair value on a recurring basis [Member] | Level 3 [Member]
Assets (Liabilities)
Total
Fair value on a recurring basis [Member] | Level 3 [Member] | Natural Gas [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	0	0
Fair value on a recurring basis [Member] | Level 3 [Member] | Oil [Member]
Assets (Liabilities)
Oil, natural gas and NGL derivatives	$ 0	$ 0