Supplemental Disclosures (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Summary of current accrued liabilities
Other	$ 3,247	$ 3,586
Total accrued liabilities	109,158	63,987
Accrued evaluated and unproved and unevaluated property costs [Member]
Summary of current accrued liabilities
Total accrued liabilities	93,965	52,605
Accrued support equipment and facilities costs [Member]
Summary of current accrued liabilities
Total accrued liabilities	437	0
Accrued stock-based compensation [Member]
Summary of current accrued liabilities
Total accrued liabilities	85	56
Accrued lease operating expenses [Member]
Summary of current accrued liabilities
Total accrued liabilities	8,385	6,251
Accrued interest on borrowings under Credit Agreement [Member]
Summary of current accrued liabilities
Total accrued liabilities	268	141
Accrued asset retirement obligations [Member]
Summary of current accrued liabilities
Total accrued liabilities	407	175
Accrued partners share of joint interest charges [Member]
Summary of current accrued liabilities
Total accrued liabilities	$ 2,364	$ 1,173