Summary of Significant Accounting Policies (Details Textual)	3 Months Ended	12 Months Ended
	Mar. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / MMBTU	Dec. 31, 2015 USD ($) $ / bbl	Dec. 31, 2015 USD ($) segment	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Purchasers	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) $ / MMBTU	Dec. 31, 2014 USD ($) $ / bbl	Dec. 31, 2014 USD ($)	Dec. 31, 2014 USD ($) Purchasers	Dec. 31, 2014 USD ($)	Dec. 31, 2013 $ / MMBTU	Dec. 31, 2013 $ / bbl	Dec. 31, 2013	Dec. 31, 2013 Purchasers	Dec. 31, 2013 USD ($)	Feb. 25, 2016 USD ($)	Jan. 31, 2016 USD ($)	Apr. 14, 2015 USD ($)
Summary of Significant Accounting Policies [Line Items]
Number of operating segments | segment					1
Amount reclassified related to deferred loan costs													$ 1,800,000
Borrowings under Credit Agreement		$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 338,199,000	$ 338,199,000	$ 338,199,000	$ 338,199,000	338,199,000
Senior unsecured notes payable		391,254,000	391,254,000	391,254,000	391,254,000	391,254,000	391,254,000	391,254,000	0	0	0	0	0
Deferred income tax reclassification									19,800,000	19,800,000	19,800,000	19,800,000	19,800,000
Restricted cash		$ 44,357,000	44,357,000	44,357,000	44,357,000	44,357,000	44,357,000	44,357,000	$ 609,000	$ 609,000	$ 609,000	$ 609,000	609,000
Billing date		30 days
Outstanding days of account receivable		60 days
Allowance for doubtful accounts		$ 0	$ 0	$ 0	0	$ 0	$ 0	0
Capitalized general and administrative costs								6,900,000					6,400,000					$ 3,700,000
Capitalized interest expense								3,900,000					2,800,000					1,900,000
Present value discounted percent of future net revenues of proved oil and natural gas reserves						10.00%
Average oil and natural gas prices			2.59	46.79					4.35	91.48				3.67	93.42
Net capitalized costs less related deferred income taxes exceeded the full-cost ceiling													0
Impairment charge of net capitalized costs	$ 21,200,000							801,166,000					0					21,229,000
Number of purchasers | Purchasers							3					3					5
Stock-based compensation (non-cash) expense								9,450,000					5,524,000					3,897,000
Common stock and restricted stock unit expense								900,000					300,000					300,000
Percentage being realized up on ultimate settlement						50.00%
Machinery and Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Useful life using the straight-line		30 years
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Accounts receivable due period		60 days
Useful life		10 years
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Accounts receivable due period		30 days
Useful life		5 years
Accounts Receivable [Member]
Summary of Significant Accounting Policies [Line Items]
Concentration risk, percentage						39.00%					44.00%					81.00%
Sales Revenue, Goods, Net [Member]
Summary of Significant Accounting Policies [Line Items]
Concentration risk, percentage						59.00%					68.00%					87.00%
Stock options [Member]
Summary of Significant Accounting Policies [Line Items]
Stock-based compensation (non-cash) expense								4,700,000					2,500,000					$ 2,200,000
Revolving Credit Facility [Member]
Summary of Significant Accounting Policies [Line Items]
Deferred loan costs		$ 1,800,000	$ 1,800,000	$ 1,800,000	1,800,000	$ 1,800,000	$ 1,800,000	1,800,000
Senior Unsecured Notes [Member]
Summary of Significant Accounting Policies [Line Items]
Deferred loan costs		$ 8,700,000	$ 8,700,000	$ 8,700,000	$ 8,700,000	$ 8,700,000	$ 8,700,000	$ 8,700,000
Senior Notes Due 2023 [Member] | Unsecured Debt [Member]
Summary of Significant Accounting Policies [Line Items]
Senior unsecured notes payable									$ 0	$ 0	$ 0	$ 0	$ 0								$ 400,000,000
Subsequent Event [Member]
Summary of Significant Accounting Policies [Line Items]
Borrowings under Credit Agreement																			$ 0
Restricted cash																				$ 42,100,000