Income Taxes (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Loss carryforwards - state	$ 35,007,000	$ 41,960,000
Enhanced oil recovery credit carryforwards	17,346,000	53,381,000
Tax credit carryover	34,837,000	34,829,000
Operating Loss Carryforwards, Expiration Dates	Our state NOLs expire in various years, starting in 2015, although most do not begin to expire until 2024.
Tax Credit Carryforward, Expiration Date	Jan. 01, 2025
Valuation Allowance, Amount	0
Tax refund due to change in tax accounting method	$ 10,600,000
Income Tax Examination, Description	We file consolidated and separate income tax returns in the U.S. federal jurisdiction and in many state jurisdictions.  The IRS concluded its examination of our 2006, 2007 and 2008 tax years during the fourth quarter of 2011 with no adjustments.  During the third quarter of 2012, the IRS concluded its audit of Encore Acquisition Company for the tax years 2008, 2009 and 2010 and Encore Operating LP for the tax years 2008 and 2009, with no significant adjustments. During the fourth quarter of 2012, the state of Mississippi concluded its audit of Denbury for the tax years 2004, 2005, 2006, and 2007, with no significant adjustments.  Our income tax returns for tax years ending 2009 through 2011 currently remain subject to examination by the appropriate taxing authorities. We have not paid any significant interest or penalties associated with our income taxes.