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Common Stock Options, Warrants And Changes In Capitalization (Details) (USD $)
In Thousands, except Share data, unless otherwise specified |
0 Months Ended | 3 Months Ended | 12 Months Ended | 1 Months Ended | 0 Months Ended | 96 Months Ended | 0 Months Ended | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Dec. 24, 2012
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Mar. 31, 2013
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Mar. 31, 2012
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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Mar. 31, 2002
Private Placement [Member]
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Dec. 31, 2012
Private Placement [Member]
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Feb. 15, 2013
Common Stock [Member]
Public Offering [Member]
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Jan. 07, 2013
Common Stock [Member]
Public Offering [Member]
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Dec. 24, 2012
Common Stock [Member]
Public Offering [Member]
|
Jan. 07, 2013
Common Stock [Member]
Public Offering [Member]
|
Dec. 05, 2011
Common Stock [Member]
Public Offering [Member]
|
Jul. 15, 2011
Common Stock [Member]
Public Offering [Member]
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Mar. 30, 2011
Common Stock [Member]
Public Offering [Member]
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May 25, 2010
Common Stock [Member]
Public Offering [Member]
|
May 25, 2010
Common Stock [Member]
Public Offering [Member]
|
May 19, 2010
Common Stock [Member]
Public Offering [Member]
|
Dec. 31, 2012
Common Stock [Member]
1999 Stock Option Plan [Member]
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Dec. 31, 2012
Common Stock [Member]
2005 Stock Incentive Plan [Member]
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Apr. 20, 2006
Common Stock [Member]
2005 Stock Incentive Plan [Member]
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Apr. 19, 2006
Common Stock [Member]
2005 Stock Incentive Plan [Member]
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Feb. 15, 2013
Utica Shale [Member]
acre
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Dec. 24, 2012
Utica Shale [Member]
acre
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Dec. 31, 2012
Utica Shale [Member]
acre
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Dec. 21, 2012
Utica Shale [Member]
acre
|
Dec. 19, 2012
Utica Shale [Member]
acre
|
Dec. 17, 2012
Utica Shale [Member]
acre
|
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| Common Stock Options, Restricted Stock, Warrants And Changes In Capitalization [Line Items] | ||||||||||||||||||||||||||||
| Number of shares available for grant (shares) | 883,000 | 3,000,000 | 1,904,606 | |||||||||||||||||||||||||
| Aggregate options granted (shares) | 627,337 | |||||||||||||||||||||||||||
| Number of options granted (shares) | 997,269 | |||||||||||||||||||||||||||
| Issuance of common stock in public offering, shares | 8,912,500 | 11,750,000 | 4,600,000 | 3,450,000 | 2,760,000 | 1,481,481 | ||||||||||||||||||||||
| Stock option, portion attributable to underwriters (shares) | 900,000 | 750,000 | 187,022 | |||||||||||||||||||||||||
| Stock option, portion available to underwriters (shares) | 1,650,000 | |||||||||||||||||||||||||||
| Share price (usd per share) | $ 38.00 | $ 38.00 | $ 29.00 | $ 28.75 | $ 32.00 | $ 13.50 | ||||||||||||||||||||||
| Proceeds from issuance of common stock, net of offering costs, and exercise of stock options | $ 427,900 | $ 357,640 | $ 427,091 | $ 307,154 | $ 21,879 | $ 325,800 | $ 427,900 | $ 460,700 | $ 128,000 | $ 94,700 | $ 84,300 | $ 21,600 | $ 325,800 | $ 460,700 | ||||||||||||||
| Gas and oil areage, undeveloped, net | 22,000 | 37,000 | 106,000 | 37,000 | 7,000 | 30,000 | ||||||||||||||||||||||
| Private placement offering units | 10,000 | |||||||||||||||||||||||||||
| Number of shares called by each warrant (shares) | 250 | |||||||||||||||||||||||||||
| Common stock, par value (usd per share) | $ 0.01 | $ 0.01 | $ 0.01 | $ 0.01 | $ 0.01 | |||||||||||||||||||||||
| Preferred stock dividend rate | 12.00% | 12.00% | 12.00% | 12.00% | 12.00% | |||||||||||||||||||||||
| Preferred stock divinded rate (for stock) | 15.00% | |||||||||||||||||||||||||||
| Warrants outstanding | 2,322,962 | |||||||||||||||||||||||||||
| Term of warrants | 10 years | |||||||||||||||||||||||||||
| Exercise price of warrants issued (usd per share) | 1.19 | |||||||||||||||||||||||||||
| Warrants expired | 8,875 | |||||||||||||||||||||||||||