Supplemental Disclosures (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Summary of current accrued liabilities
Total accrued liabilities	$ 119,361	$ 63,987
Accrued evaluated and unproved and unevaluated property costs [Member]
Summary of current accrued liabilities
Total accrued liabilities	97,101	52,605
Accrued support equipment and facilities costs [Member]
Summary of current accrued liabilities
Total accrued liabilities	2,488	0
Accrued stock-based compensation [Member]
Summary of current accrued liabilities
Total accrued liabilities	0	56
Accrued lease operating expenses [Member]
Summary of current accrued liabilities
Total accrued liabilities	9,870	6,251
Accrued interest on borrowings under Credit Agreement [Member]
Summary of current accrued liabilities
Total accrued liabilities	158	141
Accrued asset retirement obligations [Member]
Summary of current accrued liabilities
Total accrued liabilities	540	175
Accrued partners share of joint interest charges [Member]
Summary of current accrued liabilities
Total accrued liabilities	3,648	1,173
Other Accrued Liability [Member]
Summary of current accrued liabilities
Total accrued liabilities	$ 5,556	$ 3,586