Acquisitions and Divestitures - Gulf of Mexico Property Acquisitions - Final Valuation of Assets Acquired and Liabilities Assumed (Details) (Gulf of Mexico Properties, USD $) In Thousands, unless otherwise specified	0 Months Ended
Jun. 20, 2012
Gulf of Mexico Properties
Consideration paid
Cash, net of purchase price adjustments	$ 43,282
Fair value of identifiable assets acquired and liabilities assumed
Proved developed and undeveloped properties	98,725
Asset retirement obligations	(55,443)
Total identifiable net assets	$ 43,282

Acquisitions and Divestitures - Gulf of Mexico Property Acquisitions - Final Valuation of Assets Acquired and Liabilities Assumed (Details) (Gulf of Mexico Properties, USD $)
In Thousands, unless otherwise specified

0 Months Ended

Jun. 20, 2012

Gulf of Mexico Properties

Consideration paid

Cash, net of purchase price adjustments

$ 43,282

Fair value of identifiable assets acquired and liabilities assumed

Proved developed and undeveloped properties

98,725

Asset retirement obligations

(55,443)

Total identifiable net assets

$ 43,282