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USD ($)

USD ($) / shares
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&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt; &lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&lt;b&gt;3. Debt &lt;/b&gt;&lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&lt;b&gt;&lt;i&gt;Short-Term Line of Credit&lt;/i&gt;&lt;/b&gt;&lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The Company has an unsecured uncommitted money market line of credit (Line of Credit) with borrowing capacity of up to $40.0&amp;nbsp;million for a maximum of 30&amp;nbsp;days. As of March&amp;nbsp;31, 2011 and December&amp;nbsp;31, 2010 there were $13.5&amp;nbsp;million and $5.3&amp;nbsp;million in outstanding borrowings under the Line of Credit, respectively. Interest on amounts borrowed is charged at LIBOR plus a margin of approximately 1.4%. The $13.5&amp;nbsp;million of outstanding borrowings under the Line of Credit at March&amp;nbsp;31, 2011 had a weighted average interest rate of 1.7%. &lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&lt;b&gt;&lt;i&gt;Senior Secured Revolving Credit Facility &lt;/i&gt;&lt;/b&gt;&lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The Company has a senior secured revolving credit facility (Credit Agreement) with a borrowing base and lender commitments of $875&amp;nbsp;million. As of March&amp;nbsp;31, 2011 and December&amp;nbsp;31, 2010 there were $205&amp;nbsp;million and $170&amp;nbsp;million in outstanding borrowings under the Credit Agreement, respectively. The Company's total outstanding debt at March&amp;nbsp;31, 2011 under the Line of Credit and Credit Agreement was $219&amp;nbsp;million, and $23&amp;nbsp;million of letters of credit have been issued under the Credit Agreement, leaving $633&amp;nbsp;million in borrowing capacity available under the Credit Agreement. At March&amp;nbsp;31, 2011, the LIBOR and prime rate margins are between 1.75% and 2.75% based on the ratio of credit outstanding to the borrowing base, and the annual commitment fee on the unused portion of the Credit Agreement is 0.50%. &lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The maximum amount available is subject to semi-annual redeterminations of the borrowing base based on the value of the Company's proved oil and natural gas reserves in April and October of each year in accordance with the lenders' customary procedures and practices. The Company and the banks each have the unilateral right to one additional redetermination each year. The Credit Agreement is collateralized by the Company's oil and natural gas properties. &lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The Credit Agreement contains restrictive covenants that may limit the Company's ability to, among other things, incur additional indebtedness, sell assets, make loans to others, make investments, enter into mergers, enter into hedging contracts, incur liens and engage in certain other transactions without the prior consent of its lenders. The Credit Agreement contains restrictive covenants which, among other things, require the Company to maintain the following ratios: (i)&amp;nbsp;an interest coverage ratio, as defined, of 2.75 to 1.0 and (ii)&amp;nbsp;a minimum current ratio, as defined in the Credit Agreement, of 1.0 to 1.0. The Company is currently in compliance with all financial covenants and has complied with all financial covenants for all prior periods. &lt;/font&gt;&lt;/p&gt;
&lt;p style="FONT-FAMILY: times"&gt;&lt;font size="2"&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;On April&amp;nbsp;13, 2011, the Company entered into a First Amendment (Amendment) to its Credit Agreement. See Note&amp;nbsp;12 to the Condensed Financial Statements. &lt;/font&gt;&lt;/p&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;
</NonNumbericText><NonNumericTextHeader>3. Debt
Short-Term Line of Credit
&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The Company has an unsecured uncommitted money market line of credit (Line</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher SEC
 -Name Regulation S-X (SX)
 -Number 210
 -Section 02
 -Paragraph 19, 20, 22
 -Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name Statement of Financial Accounting Standard (FAS)
 -Number 129
 -Paragraph 2, 4

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