Endeavour International 10-K 17 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Mar. 13, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Document type	'10-K	'	'
Document period end date	31-Dec-13	'	'
Amendment flag	'false	'	'
Document Fiscal Period Focus	'FY	'	'
Document Fiscal Year Focus	'2013	'	'
Current fiscal year end date	'--12-31	'	'
Entity central index key	'0001112412	'	'
Entity current reporting status	'Yes	'	'
Entity filer category	'Accelerated Filer	'	'
Entity registrant name	'Endeavour International Corporation	'	'
Entity voluntary filers	'No	'	'
Entity well known seasoned issuer	'No	'	'
Entity Common Stock, Shares Outstanding	'	50.5	'
Entity Public Float	'	'	$168.50

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$34,742	$59,185	[1]
Accounts receivable	65,171	46,181
Prepaid expenses and other current assets	60,318	39,067
Total Current Assets	160,231	144,433
Property and Equipment, Net ($368,660 and $349,433 not subject to amortization at 2013 and 2012, respectively)	1,072,151	1,003,441
Goodwill	259,238	262,764
Other Assets	33,222	49,906
Total Assets	1,524,842	1,460,544
Current Liabilities:	'	'
Accounts payable	38,033	60,153
Current maturities of debt	'	15,713
Deferred revenue	20,965	'
Monetary production payment, current portion	74,167	'
Accrued expenses and other	88,625	90,100
Total Current Liabilities	221,790	165,966
Long-Term Debt	870,878	843,793
Deferred Taxes	146,213	159,959
Monetary production payment, long-term portion	92,500	'
Other Liabilities	131,370	147,692
Total Liabilities	1,462,751	1,317,410
Commitments and Contingencies	'	'
Series C Convertible Preferred Stock [Abstract]	'	'
Series C preferred stock: Liquidation preference - 37,000 and 37,000 December 31, 2013 and 2012, respectively	43,703	43,703
Stockholders Equity:	'	'
Common stock; shares issued and outstanding - 46,981 and 46,691 shares at 2013 and 2012, respectively	47	47
Additional paid-in capital	510,062	493,803
Treasury stock, at cost - 72 and 72 shares at 2013 and 2012, respectively	-587	-587
Accumulated deficit	-491,134	-393,832
Total Stockholders Equity	18,388	99,431
Total Liabilities and Stockholders Equity	1,524,842	1,460,544
Series C Preferred Stock [Member]	'	'
Series C Convertible Preferred Stock [Abstract]	'	'
Series C preferred stock: Liquidation preference - 37,000 and 37,000 December 31, 2013 and 2012, respectively	43,703	43,703
Series B Preferred Stock [Member]	'	'
Stockholders Equity:	'	'
Series B preferred stock - Liquidation preference: $3,706 and $3,588 at 2013 and 2012, respectively	'	'
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parentheticals) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property and equipment not subject to amortization	$368,660	$349,433
Common stock shares issued	46,981	46,691
Common stock shares outstanding	46,981	46,691
Treasury Stock	72	72
Series C Preferred Stock [Member]	'	'
Preferred stock liquidation preference	37,000	37,000
Series B Preferred Stock [Member]	'	'
Preferred stock liquidation preference	$3,745	$3,588

Consolidated_Statement_of_Oper

Consolidated Statement of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Consolidated Statement of Operations	'	'		'
Revenues	$337,664	$219,058		$60,091
Cost of Operations:	'	'		'
Operating expenses	105,444	58,536		17,668
Depreciation, depletion and amortization	143,048	66,564	[1]	26,478	[1]
Impairment of oil and gas properties	9,566	53,072	[1]	65,706	[1]
General and administrative	19,124	21,085		17,853
Total Expenses	277,182	199,257		127,705
Income (Loss) From Operations	60,482	19,801		-67,614
Derivatives:	'	'		'
Unrealized gains (losses)	-1,843	5,141	[1]	8,378	[1]
Interest expense	-104,516	-84,122		-44,893
Loss on early extinguishment of debt	'	-21,661	[1]	-402	[1]
Letter of credit fees	-33,425	-21,903		'
Other income (expense)	-9,735	-9,254		597
Total Other Expense	-149,519	-131,799		-36,320
Loss Before Income Taxes	-89,037	-111,998		-103,934
Petroleum Revenue Tax ("PRT") Expense (Benefit)	6,689	16,973		5,553
Corporate Tax Expense (Benefit)	-247	-2,745		21,508
Income Tax Expense	6,442	14,228		27,061
Net Loss	-95,479	-126,226	[1]	-130,995	[1]
Preferred Stock Dividends:	1,823	1,823		1,974
Net Loss to Common Stockholders	($97,302)	($128,049)		($132,969)
Net Loss per Common Share - Basic and Diluted	($2.07)	($3.01)		($3.70)
Weighted Average Number of Common Shares Outstanding:	'	'		'
Basic and Diluted	47,088	42,533		35,957
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Consolidated_Statement_of_Cash

Consolidated Statement of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Cash Flows from Operating Activities:	'		'		'
Net loss	($95,479)		($126,226)	[1]	($130,995)	[1]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
Depreciation, depletion and amortization	143,048		66,564	[1]	26,478	[1]
Impairment of oil and gas properties	9,566		53,072	[1]	65,706	[1]
Deferred tax expense (benefit)	-14,255		-17,594	[1]	21,116	[1]
Unrealized (gains) losses on derivatives	1,843		-5,141	[1]	-8,378	[1]
Amortization of non-cash compensation	3,606		4,401	[1]	3,697	[1]
Amortization of loan costs and discount	22,359		14,179	[1]	12,234	[1]
Non-cash interest expense	7,082		8,684	[1]	12,811	[1]
Loss on early extinguishment of debt	'		21,661	[1]	402	[1]
Other	16,330		15,365	[1]	1,518	[1]
Changes in operating assets and liabilities:	'		'		'
Increase in receivables	-18,991		-24,319	[1]	-531	[1]
(Increase) decrease in other current assets	1,324		-592	[1]	-13,328	[1]
Increase (decrease) in liabilities	-18,985		28,559	[1]	-30,073	[1]
Net Cash Provided by (Used in) Operating Activities	57,448		38,613	[1]	-39,343	[1]
Cash Flows From Investing Activities:	'		'		'
Capital expenditures	-225,755		-246,925	[1]	-165,062	[1]
Acquisitions, net of cash acquired	-2,787		-238,854	[1]	-33,075	[1]
Proceeds from sales, net of cash	6,774		1,407	[1]	'
(Increase) decrease in restricted cash	'		-178	[1]	31,726	[1]
Net Cash Used in Investing Activities	-221,768		-484,550	[1]	-166,411	[1]
Cash Flows From Financing Activities:	'		'		'
Repayments of borrowings	'		-274,629	[1]	-103,225	[1]
Borrowings under debt agreements, net of debt discount	'		654,023	[1]	210,000	[1]
Proceeds from issuance of common stock	'		60,805	[1]	118,444	[1]
Proceeds from issuance of monetary production payment	175,000		'		'
Repayments of monetary production payment	-8,333		'		'
Payments for early extinguishment of debt	'		-7,248	[1]	'
Financing costs paid	-25,210		-32,204	[1]	-11,401	[1]
Other financing	-1,580		-1,661	[1]	-1,295	[1]
Net Cash Provided by Financing Activities	139,877		399,086	[1]	212,523	[1]
Net Increase (Decrease) in Cash and Cash Equivalents	-24,443		-46,851	[1]	6,769	[1]
Cash and Cash Equivalents, Beginning of Period	59,185	[1]	106,036	[1]	99,267	[1]
Cash and Cash Equivalents, End of Period	$34,742		$59,185	[1]	$106,036	[1]
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Consolidated_Statement_of_Stoc

Consolidated Statement of Stockholders' Equity (USD $)	Common Stock [Member]	Treasury Stock [Member]	Additional Paid In Capital [Member]	Accumulated Deficit [Member]	Total
In Thousands
Balance, at Dec. 31, 2010	$25	($587)	$287,995	($132,815)	$154,618
Preferred stock dividends	'	'	'	-1,974	-1,974
Common stock issuance	12	'	118,433	'	118,445
Series C preferred stock conversion	1	'	9,448	'	9,449
Amortization of deferred compensation	'	'	3,697	'	3,697
Net Income (Loss)	'	'	'	-130,995	-130,995
Balance, at Dec. 31, 2011	38	-587	420,412	-265,784	154,079
Preferred stock dividends	'	'	'	-1,823	-1,823
Common stock issuance	9	'	60,796	'	60,805
Series C preferred stock conversion	'	'	6,273	'	6,273
Amortization of deferred compensation	'	'	6,033	'	6,033
Other	'	'	290	'	290
Net Income (Loss)	'	'	'	-126,226	-126,226
Balance, at Dec. 31, 2012	47	-587	493,804	-393,833	99,431
Preferred stock dividends	'	'	'	-1,823	-1,823
Issuance of warrants	'	'	11,286	'	11,286
Series C preferred stock conversion	'	'	'	'	'
Amortization of deferred compensation	'	'	4,843	'	4,843
Other	'	'	129	1	130
Net Income (Loss)	'	'	'	-95,479	-95,479
Balance, at Dec. 31, 2013	$47	($587)	$510,062	($491,134)	$18,388

General

General	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
General	'
	Note 1 – General
	Description of Business
	Endeavour International Corporation is an independent oil and gas company engaged in the exploration, development, production and acquisition of energy reserves in the U.S. and U.K.  Endeavour was incorporated under the laws of the state of Nevada on January 13, 2000.  As used in these Notes to Consolidated Financial Statements, the terms “Endeavour,”  “Company,” “we,” “us,” “our” and similar terms refer to Endeavour International Corporation and, unless the context indicates otherwise, its consolidated subsidiaries.
	2014 Liquidity and Capital Resources
	As of December 31, 2013, we had $882.6 million in outstanding indebtedness.  Being highly leveraged, servicing our debt and other long-term obligations will continue to require a significant portion of our cash flow from operations and available cash on hand.  The combination of these debt servicing requirements, capital expenditures and the delay in cash flow resulting from the Rochelle mechanical issues may exceed the cash flow from our current operations.  During 2014, our primary uses of financial resources are expected to be:
		·	our capital expenditures, primarily related to our drilling activities in the U.K.;
		·	payments for abandonment obligations,
		·	payments due under our production payments; and
		·	interest payments on existing credit facilities and payments in support of our reimbursement agreement covering our abandonment obligations.
	We believe we will be able to fund operations for the foreseeable future including our capital expenditures and other expenditure requirements based on our projections of funds generated from operations, cash available and accessing the debt and equity markets.   Since year-end 2013, we have also completed several transactions to improve our liquidity position and extended the maturities of some of our debt and other obligations.    The completion of these recent financing activities is designed to provide sufficient liquidity to replace the interruption in production at Rochelle.  These transactions include:
		·	replacing certain credit facilities which would have expired in 2014;
		·	replacing reimbursement agreements covering certain of our abandonment liabilities in the U.K. which would have expired in 2014;
		·	issuing $12.5 million in common stock; and
		·	issuing $17.5 million in 6.5% convertible debt.
	See Note 26 “Subsequent Events” for additional discussion of each of these transactions.

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Summary Of Significant Accounting Policies	'
	Note 2 – Summary of Significant Accounting Policies
	Basis of Presentation and Use of Estimates
	The accompanying financial statements have been prepared on the accrual basis of accounting in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) and have been presented on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business.  In the opinion of management, all normal recurring adjustments considered necessary for a fair presentation have been included in these financial statements.  Certain amounts for prior periods have been reclassified to conform to the current presentation.
	These accounting principles require management to use estimates, judgments and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported herein.  While management regularly reviews its estimates, actual results could differ from those estimates.
	Management believes it is reasonably possible that the following material estimates affecting the financial statements could change in the coming year:
		·	estimates of proved oil and gas reserves;
		·	estimates as to the expected future cash flow from proved oil and gas properties;
		·	estimates of future dismantlement and restoration costs;
		·	estimates of fair values used in purchase accounting; and
		·	estimates of the fair value of derivative instruments.
	Principles of Consolidation
	The accompanying consolidated financial statements include all of the accounts of Endeavour and our consolidated subsidiaries.  All significant intercompany accounts and transactions have been eliminated.  Investments in entities over which we have significant influence, but not control, are carried at cost adjusted for equity in earnings or (losses) and distributions received.
	Cash and Cash Equivalents
	We consider all highly liquid instruments with an original maturity of 90 days or less at the time of purchase to be cash equivalents.
	Restricted Cash
	Restricted cash has historically included amounts held in escrow for drilling rig commitments, as collateral for lines of credit, and for acquisitions.
	Inventories
	Materials and supplies and oil inventories are valued at the lower of cost or market value (net realizable value).  Our inventories are stated on an average cost basis.
	Full Cost Accounting for Oil and Gas Operations
	Under the full cost method of accounting for oil and gas activities, all acquisition, exploration and development costs incurred for the purpose of finding oil and gas, are capitalized and accumulated in pools on a country-by-country basis.  Capitalized costs include the cost of drilling and equipping productive wells, such as the estimated costs of dismantling and abandoning these assets, dry hole costs, lease acquisition costs, seismic and other geological and geophysical costs, delay rentals, costs related to such activities, certain directly-related employee costs and a portion of interest expense.   Employee costs associated with production and other operating activities and general corporate activities are expensed in the period incurred.
	Capitalized costs are limited on a country-by-country basis (the ceiling test).  Under the ceiling test, if the capitalized cost of the full cost pool, net of deferred taxes, exceeds the ceiling limitation, the excess is charged as an impairment expense.  The ceiling test limitation is calculated as the present value, discounted 10%, of:
		·	the future net cash flows related to estimated production of proved reserves, utilizing the average, first-day-of-the-month price for commodities;
		·	the effect of derivative instruments that qualify as cash flow hedges;
		·	the lower of cost or estimated fair value of unproved properties; and
		·	the expected income tax effects of the above items.
	We utilize a single cost center for each country where we have operations for amortization purposes.  Any sales or other conveyances of properties are treated as adjustments to the cost of oil and gas properties with no gain or loss recognized unless the operations are suspended in the entire cost center or the conveyance is significant in nature.    Proved properties are amortized on a country-by-country basis using the units of production method (“UOP”).  The amortization base in the UOP calculation includes the sum of proved property, net of accumulated DD&A, estimated future development costs (future costs to access and develop proved reserves), and asset retirement costs, less related salvage value.
	Unproved property costs include the costs associated with unevaluated properties and properties under development and are not initially included in the full cost amortization base (where proved reserves exist) until the project is evaluated.  These costs include unproved leasehold acreage, seismic data, wells and production facilities in progress and wells pending determination, together with interest costs capitalized for these projects. Seismic data costs are associated with specific unevaluated properties where the seismic data is acquired for the purpose of evaluating acreage or trends covered by a leasehold interest owned by us.
	Significant unproved properties are assessed periodically for possible impairment or reduction in value.  If a reduction in value has occurred, these property costs are considered impaired and are transferred to the related full cost pool.  Geological and geophysical costs included in unproved properties are transferred to the full cost amortization base along with the associated leasehold costs on a specific project basis. Costs associated with wells in progress and wells pending determination are transferred to the amortization base once a determination is made whether or not proved reserves can be assigned to the property.  Costs of dry holes are transferred to the amortization base immediately upon determination that the well is unsuccessful.  Unproved properties whose acquisition costs are not individually significant are aggregated and the portion of such costs estimated to be ultimately nonproductive, based on experience, are amortized to the full cost pool over an average holding period.
	In countries where the existence of proved reserves has not yet been determined, unevaluated property costs remain capitalized in unproved property cost centers until proved reserves have been established, exploration activities cease or impairment and reduction in value occurs.  If exploration activities result in the establishment of a proved reserve base, amounts in the unproved property cost center are reclassified as proved properties and become subject to amortization and the application of the ceiling test.  When it is determined that the value of unproved property costs have been permanently diminished (in part or in whole) based on the impairment evaluation and future exploration plans, the unproved property cost centers related to the area of interest are impaired, and accumulated costs charged against earnings.
	Other Property and Equipment
	Other oil and gas assets, computer equipment and furniture and fixtures are recorded at cost, less accumulated depreciation.  The assets are depreciated using the straight-line method over their estimated useful lives of two to five years.
	Capitalized Interest
	We capitalize interest on expenditures for significant exploration and development projects while activities are in progress to bring the assets to their intended use.  Capitalized interest is calculated by multiplying our weighted-average interest rate on debt by the amount of qualifying costs and is limited to gross interest expense.
	Business Combinations
	Assets and liabilities acquired through a business combination are recorded at estimated fair value.  We use all available information to make these fair value determinations, including information commonly considered by our engineers in valuing individual oil and gas properties and sales prices for similar assets.  Estimated deferred taxes are based on available information concerning the tax basis of the acquired company’s assets and liabilities and carry forwards at the merger date.
	Any excess of the acquisition cost of the acquired business over the fair value amounts assigned to assets and liabilities is recorded as goodwill.  The amount of goodwill recorded in any particular business combination can vary significantly depending upon the fair values attributed to assets acquired and liabilities assumed relative to the total acquisition cost.
	Goodwill and Intangible Assets
	We assess the carrying amount of goodwill and other indefinite-lived intangible assets by testing the asset for impairment annually at year-end, or more frequently if events or changes in circumstances indicate that the asset might be impaired.  The impairment test requires allocating goodwill and all other assets and liabilities to reporting units.  The fair value of each reporting unit is determined and compared to the book value of the reporting unit.  An impairment loss is recognized to the extent that the carrying amount exceeds the reporting unit’s fair value.
	Dismantlement, Restoration and Environmental Costs
	We recognize liabilities for asset retirement obligations associated with tangible long-lived assets, such as producing well sites, offshore production platforms, and natural gas processing plants, with a corresponding increase in the related long-lived asset.  The asset retirement cost is depreciated along with the property and equipment in the full cost pool.  The asset retirement obligation is recorded at fair value and accretion expense, recognized over the life of the property, increases the liability to its expected settlement value.  If the fair value of the estimated asset retirement obligation changes, an adjustment is recorded for both the asset retirement obligation and the asset retirement cost.
	Revenue Recognition
	We use the entitlements method to account for sales of gas production.  We may receive more or less than our entitled share of production.  Under the entitlements method, if we receive more than our entitled share of production, the imbalance is treated as a liability at the market price at the time the imbalance occurred.  If we receive less than our entitled share, the imbalance is recorded as an asset at the lower of the current market price or the market price at the time the imbalance occurred.  Oil revenues are recorded when production is transported by pipeline or the production is shipped out of our storage tanks.  Oil revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred, title has transferred and collectability of the revenue is probable.
	Significant Customers
	Our sales in the U.K. are to a limited number of customers.  For the year ended December 31, 2013, our sales to Shell U.K. Limited accounted for more than 10% of revenue.  Our sales in the U.S. are sold through our arrangements with the operators of the fields, with the majority of the sales being to J-W Operating Company.
	Derivative Instruments and Hedging Activities
	From time to time, we may utilize derivative financial instruments to hedge cash flows from operations or to hedge the fair value of financial instruments.  We also have embedded derivatives related to our debt instruments and convertible preferred stock.
	We may use derivative financial instruments with respect to a portion of our oil and gas production or a portion of our variable rate debt to achieve a more predictable cash flow by reducing our exposure to price fluctuations.  These transactions are likely to be swaps, collars or options and to be entered into with major financial institutions or commodities trading institutions.  Derivative financial instruments are intended to:
		·	reduce our exposure to declines in the market prices of crude oil and natural gas that we produce and sell;
		·	reduce our exposure to increases in interest rates, and
		·	manage cash flows in support of our annual capital expenditure budget.
	We record all derivatives at fair market value in our Consolidated Balance Sheets at the end of each period.  The accounting for the fair market value, and the changes from period to period, depends on the intended use of the derivative and the resulting designation.  This evaluation is determined at each derivative’s inception and begins with the decision to account for the derivative as a hedge, if applicable.  The accounting for changes in the fair value of a derivative instrument that is not accounted for as a hedge is included in other (income) expense as an unrealized gain or loss.  At December 31, 2013 and 2012, we had  no outstanding derivatives that were accounted for as a hedge.
	Concentrations of Credit and Market Risk
	Financial instruments that potentially subject us to concentrations of credit risk consist principally of cash deposits at financial institutions.  At various times during the year, we may exceed the federally insured limits.  To mitigate this risk, we place our cash deposits only with high credit quality institutions.  Management believes the risk of loss is minimal.
	As an independent oil and gas producer, our revenue, profitability and future rate of growth are substantially dependent upon prevailing prices for oil and gas, which are dependent upon numerous factors beyond our control, such as economic, political and regulatory developments and competition from other sources of energy.  The energy markets have historically been very volatile, and there can be no assurance that oil and gas prices will not be subject to wide fluctuations in the future.  A substantial or extended decline in oil and gas prices could have a material adverse effect on our financial position, results of operations, cash flows and our access to capital and on the quantities of oil and gas reserves that may be economically produced.
	Foreign Currency Translation
	The U.S. dollar is the functional currency for all of our existing operations, as a majority of all revenue and financing transactions in these operations are denominated in U.S. dollars.  For foreign operations with the U.S. dollar as the functional currency, monetary assets and liabilities are remeasured into U.S. dollars at the exchange rate on the balance sheet date.  Nonmonetary assets and liabilities are translated into U.S. dollars at historical exchange rates.  Income and expense items are translated at exchange rates prevailing during each period.  Adjustments are recognized currently as a component of foreign currency gain or loss and deferred income taxes.  To the extent that business transactions are not denominated in U.S. dollars, we are exposed to foreign currency exchange rate risk.
	Income Taxes
	We use the liability method of accounting for income taxes under which deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities, and their respective tax bases.  Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled.  The effect on deferred tax assets and liabilities of a change in tax rates is recognized as part of the provision for income taxes in the period that includes the enactment date.  Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion of, or all of, the deferred tax assets will not be realized.
	Share-Based Payments
	We recognize all share-based payments to employees, including grants of employee stock options, based on their fair values.  The share-based compensation cost is measured at the grant date, based on the calculated fair value of the award, and is recognized as general and administrative expense over the employee’s requisite service period (generally the vesting period of the equity award).
	It is our policy to use authorized but unissued shares of stock when stock options are exercised.  At December 31, 2013, we had approximately 1.8 million additional shares available for issuance pursuant to our existing stock incentive plans.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Business Combinations	'
	Note 3 – Business Combinations
	On December 23, 2011, we entered into a Sale and Purchase Agreement (the “Purchase Agreement”), through our wholly owned subsidiary EEUK, with ConocoPhillips (U.K.) Limited, ConocoPhillips Petroleum Limited and ConocoPhillips (U.K.) Lambda Limited, subsidiaries of ConocoPhillips (collectively, the “Sellers”), to acquire their interest in three producing U.K. oil fields in the Central North Sea.
	On May 31, 2012, we closed the Alba field portion of the acquisition, which consisted of an additional 23.43% interest in the Alba field.  This increased our total working interest in the Alba field to 25.68%.  The Alba Acquisition was closed for aggregate cash consideration of approximately $229.6 million.
	Upon the closing of the Alba Acquisition, the net proceeds from the offering of our 2018 Notes were released from escrow.  We used approximately $205 million of the net proceeds from the sale of the Senior Notes due 2018 together with approximately $24 million of borrowings under our Revolving Credit Facility with Cyan, as administrative agent and the other lenders party thereto, to fund the cash consideration for the acquisition of the Alba field portion of the COP Acquisition.  Additional information on these related financing transactions is discussed in Note 10.
	The acquisition of the additional interest in the Alba field was accounted for using the business combination method.  The following summarizes the allocation of the purchase price for the Alba Acquisition:
	Purchase Price	$	255,400
	Purchase Price adjustments for estimated after-tax cash flows from the acquired asset and
	interest costs from effective date of January 1, 2011 to closing		-25,823
	Total purchase price	$	229,577
	Allocation of purchase price:
	Property and equipment	$	191,507
	Goodwill		47,353
	Current assets		24,632
	Current liabilities		-12,815
	Deferred tax liability		-6,999
	Other long-term liabilities		-14,101
	Total purchase price	$	229,577
	Goodwill was the excess of the consideration transferred over the net assets recognized and represents the future economic benefits arising from assets acquired that could not be individually identified and separately recognized.  The assessments of the fair values of oil and gas properties acquired were based on projections of expected future net cash flows, discounted to present value.
	Revenues and income from operations associated with the acquired interest in the Alba field for the period from May 31, 2012 through December 31, 2012 were $119.7 million and $13.7 million, respectively.
	After substantial effort and extensions, we and the Sellers were unable to reach the unanimous agreement and consent required to transfer the interests in the two remaining U.K. oil fields and the Purchase Agreement terminated in accordance with its terms on December 14, 2012.  As previously disclosed, we paid a $10 million deposit in connection with the acquisition of the interests in the two remaining fields, which the Sellers retained.

Prepaid_Expenses_And_Other_Cur

Prepaid Expenses And Other Current Assets	12 Months Ended
	Dec. 31, 2013
Prepaid Expenses And Other Current Assets [Abstract]	'
Prepaid Expenses And Other Current Assets	'
	Note 4 – Prepaid Expenses and Other Current Assets
	Prepaid expenses and other current assets consisted of the following:
		December 31,
		2013		2012
	Prepaid well and drilling costs	$	24	$	2,843
	Prepaid insurance		3,707		3,330
	Inventory		5,117		5,127
	Deferred tax asset		26,583		26,161
	Deferred financing costs - current portion		22,134		—
	Other		2,753		1,606
		$	60,318	$	39,067

Property_And_Equipment

Property And Equipment	12 Months Ended
	Dec. 31, 2013
Property and Equipment [Abstract]	'
Property And Equipment	'
	Note 5 – Property and Equipment
	Property and equipment included the following:
		December 31,
		2013			2012
	Oil and gas properties under the full cost method:
	Subject to amortization	$	1,084,669		$	915,801
	Not subject to amortization:
	Acquired in 2013		52,748			-
	Acquired in 2012		138,641			141,837
	Acquired in 2011		99,740			107,510
	Acquired prior to 2011		77,531			100,086
			1,453,329			1,265,234
	Computers, furniture and fixtures		8,734			8,863
	Total property and equipment		1,462,063			1,274,097
	Accumulated depreciation, depletion and amortization		-389,912			-270,656
	Net property and equipment	$	1,072,151		$	1,003,441
	The costs not subject to amortization include
		·		values assigned to unproved reserves acquired,
		·		exploration costs such as drilling costs for projects awaiting approved development plans or the determination of whether or not proved reserves can be assigned, and
		·		other seismic and geological and geophysical costs.
	These costs are transferred to the amortization base when it is determined whether or not proved reserves can be assigned to such properties.  This analysis is dependent upon well performance, results of infield drilling, approval of development plans, drilling results and development of identified projects and periodic assessment of reserves.  We expect acquisition costs and exploration costs excluded from amortization to be transferred to the amortization base over the next three years due to a combination of well performance and results of infield drilling relating to currently producing assets and the drilling and development of identified projects, such as the Rochelle field.  Because of the nature of offshore oil and gas activities, development activities, including sanctioning and regulatory approvals, may take a significant amount of time to implement.  Even though our expectation is that most costs not subject to amortization are to be transferred to the amortization base over the next three years, it is not uncommon for the cycle times to be longer.  We have one U.K. field, Columbus, where costs have been excluded from amortization for greater than five years; however, we continue to work on the development planning for the field.
	The following is a summary of our oil and gas properties not subject to amortization as of December 31, 2013:
	Costs Incurred in the Year Ended December 31,
			2013			2012		2011		Prior to 2011		Total
	Acquisition costs		$	384		$	48,409	$	48,995	$	35,409	$	133,197
	Exploration costs			35,584			77,200		47,656		42,122		202,562
	Capitalized interest			16,780			13,032		3,089		—		32,901
	Total oil and gas properties not
	subject to amortization		$	52,748		$	138,641	$	99,740	$	77,531	$	368,660
	During 2013,  2012 and 2011, we capitalized $12.4 million, $17.9 million and $13.3 million, respectively, in certain directly related employee costs.  During 2013,  2012 and 2011, we capitalized $24.0 million, $26.9 million and $14.7 million, respectively, in interest.
	During 2013,  2012 and 2011,  we recorded $9.6 million, $53.1 million and $65.7 million, respectively, of impairment through the application of the full cost ceiling test.  The primary reason for the 2013 impairment was the evaluation of certain of our U.S. assets not subject to amortization which we no longer intend to pursue and accordingly are included in the full cost pool.  We did not have an impairment of our U.K. oil and gas properties through the application of the full cost ceiling test at the end of 2013.  The 2012 impairment was primarily due to the decline in U.S. oil and gas prices.  The 2011 impairment was primarily related to declines in U.S. gas prices and the impact of our determination that the likely economic returns in the future would not warrant further investment in our test wells in the Alabama area.  Our decision to discontinue activities in that area resulted in the reclassification of related amounts as being evaluated for full cost accounting purposes.
	Assets Acquisitions and Divestitures
	Marcellus and Haynesville
	On October 26, 2012, we completed a nonmonetary exchange with our domestic co-venturer whereby we exchanged our Bull Bayou Haynesville and Willow Springs Cotton Valley properties for all of the co-venturer’s upstream and midstream interests in the Pennsylvania Marcellus area.  In parallel, we secured a third party gas gathering agreement for the Daniel Project in Cameron County, Pennsylvania.  We operated and controlled the Marcellus assets while retaining a 50% position in our remaining producing Haynesville acreage.
	On November 8, 2013, we closed on a purchase and sale agreement and formed a joint venture partnership with Samson Exploration LLC (“Samson”), which included a sale of 50% of our upstream and midstream assets in the Pennsylvania Marcellus area to Samson.  The agreement provides for the joint development of the Marcellus assets and includes a financing component.  This joint venture provides the necessary capital for the next development phase in the core Daniel Field in Cameron County, Pennsylvania.
	Business Combination
	On May 31, 2012, we closed the Alba Acquisition, which consisted of an additional 23.43% interest in the Alba field.  This increased our total working interest in the Alba field to 25.68%.  The Alba Acquisition was closed for aggregate cash consideration of approximately $229.6 million.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2013
Goodwill [Abstract]	'
Goodwill	'
	Note 6 – Goodwill
	In connection with several business acquisitions, we recorded goodwill for the excess of the purchase price over the value assigned to individual assets acquired and liabilities assumed.  Changes to goodwill for the year ended December 31, 2013 and 2012 were related to the Alba Acquisition as follows:
		December 31,
		2013		2012
	Balance at beginning of year	$	262,764	$	211,886
	Purchase price adjustment		-3,526		50,878
	Balance at end of year	$	259,238	$	262,764

Other_Assets

Other Assets	12 Months Ended
	Dec. 31, 2013
Other Assets [Abstract]	'
Other Assets	'
	Note 7 – Other Assets
	Other long-term assets consisted of the following at December 31:
		2013		2012
	Debt issuance costs	$	20,856	$	30,599
	Deferred issuance costs related to reimbursement agreements		—		11,290
	Deposits related to SM Energy litigation		6,000		6,000
	Other		6,366		2,017
		$	33,222	$	49,906
	Debt issuance costs and deferred issuance costs related to our reimbursement agreements are amortized over the life of the related obligation.
	As discussed in Note 21, we are in litigation concerning the terminated acquisition of properties from SM Energy.  We paid $6.0 million in a deposit upon executing the acquisition agreement with SM Energy, and SM Energy has retained the deposit, which we believe we are entitled to recover.

Accrued_Expenses_And_Other_Cur

Accrued Expenses And Other Current Liabilities	12 Months Ended
	Dec. 31, 2013
Accrued Expenses And Other Current Liabilities [Abstract]	'
Accrued Expenses And Other Current Liabilities	'
	Note 8 – Accrued Expenses and Other Current Liabilities
	We had the following accrued expenses and other current liabilities outstanding:
		December 31,
		2013		2012
	Foreign taxes payable	$	2,875	$	18,989
	Accrued interest		29,512		25,932
	Preferred dividends		1,774		1,617
	Accrued compensation		3,210		1,882
	Current portion of asset retirement obligations		48,895		36,255
	Other		2,359		5,425
		$	88,625	$	90,100

Deferred_Revenue

Deferred Revenue	12 Months Ended
	Dec. 31, 2013
Deferred Revenue [Abstract]	'
Deferred Revenue	'
	Note 9 – Deferred Revenue
	For certain of our U.K. fields, we sell production on a monthly basis; however, the production remains in the field’s storage tanks.  The inventory associated with these sales remains on our balance sheet and the revenue is deferred until the production is shipped out of our storage tanks.
	In February and September 2013, we entered into forward sale agreements with one of our established purchasers for payments of approximately $22.5 million each.  This effectively hedged a portion of production from our U.K. North Sea assets by locking in pricing for in excess of 200,000 barrels of oil each, over a six month delivery period.  Payment for these agreements was received in March and September 2013.  The February forward sale commitment was fulfilled in June 2013 and the September forward sale commitment is expect to be fulfilled by the end of the first quarter of 2014.  The forward sale liabilities are included in deferred revenue until the purchaser takes possession of the inventory from the field’s storage tanks.

Debt_Obligations

Debt Obligations	12 Months Ended
	Dec. 31, 2013
Debt Obligations [Abstract]	'
Debt Obligations	'
	Note 10 – Debt Obligations
	Our debt consisted of the following at December 31:
		2013		2012
	Senior notes, 12% fixed rate, due 2018	$	554,000	$	554,000
	Convertible senior notes, 5.5% fixed rate, due 2016		135,000		135,000
	Revolving credit facility, 13% fixed rate, due 2014		115,163		115,163
	Convertible bonds, 11.5% until March 31, 2014 and 7.5% thereafter, due 2016		78,437		70,029
			882,600		874,192
	Less:  debt discount, net of premium		-11,722		-14,686
	Less:  current maturities		—		-15,713
	Long-term debt	$	870,878	$	843,793
	Senior Notes
	On February 23, 2012, we closed the private placement of $350 million aggregate principal amount of 12% first priority notes due 2018 (the “First Priority Notes”) and $150 million aggregate principal amount of 12% second priority notes due 2018 (the “Second Priority Notes,” and, together with the First Priority Notes, the “2018 Notes”).  Each series of 2018 Notes issued in February 2012 was priced at 96% of par, at a yield to maturity of 12.975% for the First Priority Notes and 12.954% for the Second Priority Notes, for an aggregate $20 million discount.  We also paid approximately $21 million in other financing costs related to the 2018 Notes.
	On May 31, 2012, concurrent with the closing of the Alba Acquisition, the net proceeds were used to fund the acquisition and repay all outstanding amounts under a senior term loan (“Senior Term Loan”).
	On October 15, 2012 we completed a private placement of an additional $54 million aggregate principal amount of our First Priority Notes, due 2018, priced at 109% of par.  In connection with the offering of the First Priority Notes, we received net proceeds of $57.9 million.  The new first priority notes and those first priority notes initially issued in February 2012 are treated as a single class of debt securities under the same indenture.  We utilized a portion of the proceeds from the October 2012 offering to retire the $25 million outstanding under our 12% senior subordinated notes due 2014.  We used the remainder of the net proceeds to finance a portion of the construction, improvement and other capital costs related to our U.S. and U.K. properties.
	Revolving Credit Facility
	On April 12, 2012, we entered into a $100 million Revolving Credit Facility, with Cyan, as administrative agent, and borrowed $40 million, subsequently increased to $115 million.
	On January 24, 2014, we repaid the balance outstanding under the Revolving Credit Facility with proceeds from the Term Loan Facility.  Following the repayment, the Revolving Credit Facility was terminated and all of the liens on the collateral securing our obligations were released.  For additional discussion of the Term Loan Facility, see Note 26 “Subsequent Events.”
	5.5% Convertible Senior Notes
	In July 2011, we issued $135 million aggregate principal amount of our 5.5% convertible senior notes due July 15, 2016 (the “5.5% Convertible Senior Notes”).  Interest on these notes is payable semiannually at a rate of 5.5% per annum.  The 5.5% Convertible Senior Notes are convertible into shares of our common stock at an initial conversion rate of 54.019 shares (equivalent to $18.51 per share) of common stock per $1,000 principal amount of the notes, subject to certain anti-dilution adjustments.  In addition, following certain Make-Whole Fundamental Changes, as defined, we will increase the conversion rate for a holder who elects to convert its 5.5% Convertible Senior Notes.
	The 5.5% Convertible Senior Notes are unsecured but guaranteed by our existing material domestic subsidiaries. We may not redeem the 5.5% Convertible Senior Notes prior to their maturity.  The indenture governing the 5.5% Convertible Senior Notes provides for customary events of default.
	If we undergo a “fundamental change” as defined, the holders of the 5.5% Convertible Senior Notes have the right, subject to certain conditions, to redeem the 5.5% Convertible Senior Notes and accrued interest.  The 5.5% Convertible Senior Notes may become immediately due upon the occurrence of certain events of default, as defined.
	11.5% Convertible Bonds
	In January 2008, we issued 11.5% convertible bonds (the “11.5% Convertible Bonds”) for gross proceeds of $40 million pursuant to a private offering to a sophisticated investor in Norway.  The net proceeds from the issuance of the 11.5% Convertible Bonds were used to repay a portion of our outstanding indebtedness.  The 11.5% Convertible Bonds currently bear interest at a rate of 11.5% per annum and 7.5%  per annum on and after March 31, 2014.  Interest is compounded quarterly and added to the outstanding principal balance each quarter.  The bonds have a maturity date of January 24, 2016.
	The bonds are convertible into shares of our common stock at a conversion price of $16.52 per $1,000 of principal, which represents a conversion rate of approximately 61 shares of our common stock per $1,000 of principal.  The conversion price will be adjusted in accordance with the terms of the bonds upon occurrence of certain events, including payment of common stock dividends, common stock splits or issuance of common stock at a price below the then current market price. The holders of the 11.5% Convertible Bonds may exercise a put right, and the occurrence of the conversion price reset if such put right is not exercised, on January 24, 2016.
	If we undergo a “change of control” as defined, the holders of the bonds have the right, subject to certain conditions, to redeem the bonds and accrued interest.  The bonds may become immediately due upon the occurrence of certain events of default, as defined.
	Two derivatives are associated with the conversion and change in control features of the 11.5% Convertible Bonds.  At December 31, 2013, the combined fair market value of these derivatives is $5.7 million, reflecting a $1.3 million increase during 2013 that was recorded in unrealized gains (losses) on derivatives.
	Five Year Debt Maturities
	Principal maturities of debt at December 31, 2013 are as follows:
	2014 (balance repaid in full with proceeds from the Term Loan Facility)	$	115,163
	2015		—
	2016		213,437
	2017		—
	2018		554,000
	Thereafter		—
	Fair Value
	The fair value of our outstanding debt obligations was $868.4 million and $869.5 million at December 31, 2013 and 2012, respectively.  The fair values of long-term debt were determined based upon external market quotes for our 2018 Notes and 5.5% Convertible Senior Notes and discounted cash flows for other debt, which results in a Level 3 fair-value measurement.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Taxes [Abstract]	'
Income Taxes	'
	Note 11 – Income Taxes
	The income (loss) before income taxes and the components of the income tax expense (benefit) recognized on the Consolidated Statement of Income are as follows:
	(Amounts in thousands)	U.K.			U.S.			Other		Total
	Year Ended December 31, 2013:
	Net income (loss) before taxes	$	-35,273		$	-44,591		$	-9,173	$	-89,037
	PRT tax current expense		20,667			—			—		20,667
	PRT tax deferred benefit		-13,978			—			—		-13,978
	PRT tax expense		6,689			—			—		6,689
	Corporate current expense		—			—			30		30
	Corporate deferred benefit		-277			—			—		-277
	Corporate tax expense (benefit)		-277			—			30		-247
	Total tax expense		6,412			—			30		6,442
	Net income (loss) after taxes	$	-41,685		$	-44,591		$	-9,203	$	-95,479
	Year Ended December 31, 2012:
	Net income (loss) before taxes	$	-22,959		$	-91,383		$	2,344	$	-111,998
	PRT tax current expense		31,796			—			—		31,796
	PRT tax deferred benefit		-14,823			—			—		-14,823
	PRT tax expense		16,973			—			—		16,973
	Corporate current expense		—			—			26		26
	Corporate deferred benefit		-11,358			—			—		-11,358
	Deferred tax expense related to U.K. tax law change		8,587			—			—		8,587
	Corporate tax expense (benefit)		-2,771			—			26		-2,745
	Total tax expense		14,202			—			26		14,228
	Net income (loss) after taxes	$	-37,161		$	-91,383		$	2,318	$	-126,226
	Year Ended December 31, 2011:
	Net income (loss) before taxes	$	-9,806		$	-99,409		$	5,281	$	-103,934
	PRT tax current expense		5,926	—		—			—		5,926
	PRT tax deferred benefit		-373			—			—		-373
	PRT tax expense		5,553			—			—		5,553
	Corporate current expense		—			4			15		19
	Corporate deferred benefit		-3,935			—			—		-3,935
	Deferred tax expense related to U.K. tax law change		25,424			—			—		25,424
	Corporate tax expense		21,489			4			15		21,508
	Total tax (benefit) expense		27,042			4			15		27,061
	Net income (loss) after taxes	$	-36,848		$	-99,413		$	5,266	$	-130,995
	Effective Tax Rate Reconciliation
	The following table presents the principal reasons for the difference between our effective tax rates and the United States federal statutory income tax rate of 35%.
		Year Ended December 31,
		2013			2012			2011
	Federal income tax benefit at statutory rate	$	-31,163		$	-39,199		$	-36,378
	Taxation of foreign operations		21,998			5,859			3,254
	Effect of out-of-period adjustment		—			6,997			—
	Change in valuation allowance – U.S.		15,343			30,329			24,604
	U.K. tax increase from tax law and rate changes		—			8,587			25,424
	Deemed foreign dividend of wholly owned subsidiaries		—			—			8,572
	Disallowed executive compensation		247			1,655			1,585
	Other		17			—			—
	Total Income Tax Expense	$	6,442		$	14,228		$	27,061
	Effective Income Tax Rate		-7%			-13%			-26%
	During 2013,  2012 and 2011, we incurred taxes primarily related to our operations in the U.K.  In 2013,  2012 and 2011, we had losses before taxes of $44.6 million, $91.4 million and $99.4 million, respectively, in the U.S. and we did not record any income tax benefits on these losses as there was no assurance that we could generate any future U.S. taxable earnings.  As a result, we  recorded a valuation allowance on the full amount of all deferred tax assets generated in the U.S.
	Deferred Tax Assets and Liabilities
	Deferred income taxes result from the net tax effects of temporary timing differences between the carrying amounts of assets and liabilities reflected on the financial statements and the amounts recognized for income tax purposes.  The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities are as follows at December 31:
		2013			2012
	Deferred tax asset:
	Deferred compensation	$	2,401		$	2,268
	Asset retirement obligation		84,941			87,787
	Net operating loss and capital loss carryforward		423,374			334,121
	Unrealized loss on embedded derivative instruments		1,265			1,084
	Property, plant and equipment		14,086			19,596
	Inventory / other		2,185			8,089
	Total deferred tax assets		528,252			452,945
	Less valuation allowance		-103,171			-84,691
	Total deferred tax assets after valuation allowance		425,081			368,254
Deferred tax liability:
Property, plant and equipment		-526,274			-478,719
Petroleum revenue tax, net of tax benefit		-17,967			-22,703
Debt discount		-471			-630
Total deferred tax liabilities		-544,712			-502,052
Net deferred tax liability	$	-119,631		$	-133,798
Tax Attributes
At December 31, 2013, we had the following tax attributes available to reduce future income taxes:
			As of December 31,
			2013					2012
	Types of Tax Attributes		Years of Expiration		Carry-forward Amount			Years of Expiration	Carry-forward Amount
U.K.
Corporate tax	NOL		Indefinite		$	638,466		Indefinite	$	500,789
Supplemental Corporate tax	NOL		Indefinite			455,318		Indefinite		378,602
U.S.
Corporate Income tax	NOL		2023 - 2033			232,745		2023 - 2032		177,206
State Income tax	NOL		2014 - 2033			83,613
Capital gains tax	Capital loss		2015			1,848		2015		1,848
As of December 31, 2013, the U.K. tax attributes shown above have been recognized for financial statement reporting purposes to reduce deferred tax liability.
Valuation Allowances and Unrecognized Tax Benefits
Recognition of the benefits of the deferred tax assets requires that we generate future taxable income.  In the U.S., there can be no assurance that we will generate any earnings or any specific level of earnings in future years.  Therefore, we have established a valuation allowance for deferred tax assets of approximately $103.0 million and $84.7 million as of December 31, 2013 and 2012, respectively, primarily related to our U.S. operations.  During 2013, the valuation allowance in the U.S. increased $18.3 million, $2.9 million for net revisions and $15.4 million due to net operating losses, and increased $.2 million for net operating losses in other jurisdictions.  During 2012, the valuation allowance in the U.S. increased $29.1 million due to net operating losses and decreased $3.0 million in other jurisdictions.  During 2011, the valuation allowance in the U.S. increased $24.6 million due to net operating losses and decreased $3.9 million in other jurisdictions.  For U.S. federal income tax purposes, certain limitations are imposed on an entity’s ability to utilize its net operating losses (“NOLs”) in future periods if a change of control, as defined for federal income tax purposes, has taken place.  In general terms, the limitation on utilization of NOLs and other tax attributes during any one year is determined by the value of an acquired entity at the date of the change of control multiplied by the then-existing long-term, tax-exempt interest rate.  We have determined that, for federal income tax purposes, a change of control occurred during 2004 and 2007, however, we do not believe such limitations will significantly impact our ability to utilize the NOL.  The timing of NOL utilization will be determined by our future net income.
Uncertain Tax Positions
At December 31, 2013, we have an unrecognized tax benefit of $6.8 million relating to various U.K. tax matters.  Any interest and penalties that may be incurred as part of this liability would be recognized as a component of interest expense and other expense, respectively.  As of December 31, 2013,  no interest or penalty expense had been incurred.
The following represents a reconciliation of the change in our unrecognized tax benefits, for the year ended December 31, 2013.
		Year Ended
		December 31,
		2013			2012			2011
Balance at the beginning of the year	$	6,820		$	-		$	-
Increase in unrecognized tax benefits from current period tax position		-			6,820			-
Balance at the end of the year	$	6,820		$	6,820		$	-
As of December 31, 2013, we believe that no current tax positions that have resulted in unrecognized tax benefits will significantly increase or decrease within the next year.  If recognized, a $1 million tax benefit would have resulted to impact our effective tax rate.
The following tax years remain subject to examination:
Tax Jurisdiction
U.K.	2012 - 2013
All others	2010 - 2013
Foreign Earnings and Credits
As of December 31, 2013, we had de minimus unremitted earnings in our foreign subsidiaries.  If these unremitted earnings had been dividend to the U.S., the U.S. NOLs not subject to the limitations mentioned above would be fully available to offset any incremental U.S. federal income tax.  Further, the foreign tax credits associated with the unremitted earnings would be sufficient to offset any incremental U.S. tax liabilities associated with the dividend.

Monetary_Production_Payment

Monetary Production Payment	12 Months Ended
	Dec. 31, 2013
Monetary Production Payment [Abstract]	'
Monetary Production Payment	'
	Note 12 – Monetary Production Payment
	Our monetary production payment liability, net of repayments, consisted of the following at December 31, 2013:
		December 31,
		2013			2012
	Monetary production payment	$	166,667		$	—
	Less:  current portion		74,167			—
	Long-term monetary production payment	$	92,500		$	—
	During 2013, we entered into various monetary production payment arrangements (collectively  , the “Monetary Production Payments”) covering the proceeds of sale from a portion of EEUK’s entitlement to production from its interests in the certain fields located in the U.K. sector of the North Sea.  Pursuant to the Monetary Production Payments, our obligations will cease upon the earlier of the repayment of amounts outstanding or production from the applicable licences permanently ceasing.  We issued the Monetary Production Payments in the following manner:
		·		In March through May 2013, a total of $125.0 million, with an effective interest rate of 10.0%, associated with production from our interests in the Alba and Bacchus fields.
		·		In August 2013, $25 million, with an effective interest rate of 8.75%, associated with production from our interests in the Alba and Bacchus fields.
		·		In December 2013, $25 million, with an effective interest rate of 9.75%, associated with production from our interests in the Rochelle field.
	Principal and interest payments are payable within 20 days after the end of each calendar quarter.  In January 2014, we made a principal payment of $5.0 million and payments for the next three quarters are expected to be $5.8 million each.  In January and April 2015, the principal payments will be $51.7 million each.  The final three payments range from $10 million to $18 million, with the final payment to be made in January 2016.
	Our obligations under the Monetary Production Payments are secured by first priority liens over our interests in the applicable license and related joint operating agreements and sales proceeds accounts.  Our obligations are also secured by second priority liens over certain of our other licenses, joint operating agreements and assets.  The second priority liens are subordinated to the security granted to the holders of our revolving credit facility dated April 12, 2012 pursuant to an intercreditor agreement.
	In connection with the initial Monetary Production Payment, we issued warrants to purchase a total of 3,440,000 shares of our common stock at an exercise price of $3.014 per share, expiring on April 30, 2018, and warrants to purchase a total of 560,000 shares of our common stock at an exercise price of $3.685 per share, expiring on May 21, 2018.  We have incurred $26.6 million in costs related to the issuance of the Monetary Production Payments, including $7.6 million related to the fair market value of the warrants issued.
	Both warrant agreements are subject to customary anti-dilution provisions and include a cashless exercise provision entitling the investors to surrender a portion of the underlying common stock that has a value equal to the aggregate exercise price in lieu of paying cash upon exercise of a warrant.

Other_Liabilities

Other Liabilities	12 Months Ended
	Dec. 31, 2013
Other Liabilities [Abstract]	'
Other Liabilities	'
	Note 13 – Other Liabilities
	Other liabilities included the following:
		December 31,
		2013		2012
	Asset retirement obligations	$	121,534	$	139,821
	Long-term derivative liabilities		9,245		7,402
	Other		591		469
	Total Other Liabilities	$	131,370	$	147,692
	Our asset retirement obligations relate to obligation of the plugging and abandonment of oil and gas properties.  The asset retirement obligation is recorded at fair value and accretion expense, recognized over the life of the property, increases the liability to its expected settlement value.  If the fair value of the estimated asset retirement obligation changes, an adjustment is recorded for both the asset retirement obligation and the asset retirement cost.  The following table provides a rollforward of the asset retirement obligations for the year ended December 31, 2013 and 2012:
		Year Ended
		December 31,
		2013		2012
	Carrying amount of asset retirement obligations, as of beginning of period	$	176,076	$	47,258
	Increase (decrease) due to revised estimates		-10,304		102,447
	Accretion expense (included in DD&A expense)		23,793		7,542
	Impact of foreign currency exchange rate changes		3,205		3,019
	Payment of asset retirement obligations		-27,690		-8,521
	Liabilities incurred and assumed		5,349		24,331
	Carrying amount of asset retirement obligations, as of end of year		170,429		176,076
	Less: current portion of asset retirement obligations		-48,895		-36,255
	Long-term asset retirement obligations	$	121,534	$	139,821

Equity

Equity	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Equity	'
	Note 14 –  Equity
	The activity in shares of our common and preferred stock during 2013,  2012 and 2011 included the following:
			Year Ended December 31, 2013
			2013		2012	2011
	Common Stock:
	Outstanding at the beginning of the year		46,691		37,663	24,784
	Issuance of common stock		—		8,625	11,531
	Exercise of stock options		23		—	93
	Conversion of preferred stock		—		—	914
	Issuance of stock based compensation		267		403	341
	Outstanding at the end of the year		46,981		46,691	37,663
	Series B Preferred Stock:
	Outstanding at the end of the year		20		20	20
	Series C Convertible Preferred Stock:
	Outstanding at the beginning of the year		37		37	45
	Conversion to common stock		—		—	-8
	Outstanding at the end of the year		37		37	37
	Treasury Stock:
	Outstanding at the end of the year		-72		-72	-72
	Common Stock
	The Common Stock is $0.001 par value common stock, and 125,000,000 shares are authorized.
	In January 2013, in connection with our entry into the LOC Procurement Agreement, we issued warrants to purchase a total of 1,000,000 shares of our common stock at an exercise price of $7.31 per share to the investor.  The warrants expire on January 9, 2018 and are subject to customary anti-dilution provisions.  Additional information concerning the LOC Procurement Agreement can be found in Note 22.
	In March 2013 we entered into warrant agreements through which we issued 3,440,000 warrants to purchase shares of our common stock at an exercise price of $3.014 per share, expiring on April 30, 2018, and warrants to purchase a total of 560,000 shares of our common stock at an exercise price of $3.685 per share, expiring on May 21, 2018.  The Warrant Agreements were entered into in connection with our Monetary Production Payment, additional discussion of which can be found in Note 12.  Both warrant agreements are subject to customary anti-dilution provisions and include a cashless exercise provision which entitles investors to surrender a portion of the underlying common stock that has a value equal to the aggregate exercise price in lieu of paying cash upon exercise of a warrant.
	In June 2012, we completed an underwritten public offering of 8.6 million shares of common stock at a price of $7.50 per common share ($7.13 per common share, net of underwriting discounts) for net proceeds of $60.8 million.
	In May 2012, we entered into warrant agreements through which we issued certain investors warrants to purchase a total of 2,000,000 shares of our common stock at an exercise price of $10.50 per share.  The Warrant Agreements were entered into in connection with the May 31, 2012 reimbursement agreement (see Note 19 for additional discussion of this reimbursement agreement). The terms of each of the Warrant Agreements are substantially identical.  The warrants expire on January 24, 2016 and are subject to customary anti-dilution provisions.  We also agreed to provide the investors with customary resale registration rights as soon as reasonably practicable.
	In March 2011, we completed an underwritten public offering of 11.5 million shares of common stock at a price of $11.00 per common share ($10.34 per common share, net of underwriting discounts) for net proceeds of $118.4 million.  In April 2011, we used a portion of the offering proceeds to redeem all $81.25 million of our outstanding 6% senior notes.
	See Note 26 “Subsequent Events” for a discussion of common stock and warrants issued in 2014.
	Series C Convertible Preferred Stock
	We have 37,000 shares of Series C convertible preferred stock (the “Series C Preferred Stock”) outstanding, convertible into 4.2 million shares of common stock.  The Series C Preferred Stock is convertible into common stock at any time at the option of the holders at a conversion price of $8.75, plus accrued but unpaid dividends.  The Series C Preferred Stock ranks senior to any of our other existing or future shares of capital stock.  Dividends on the Series C Preferred Stock are:
		·		cumulative;
		·		compounded quarterly based on the original issue price;
		·		payable in cash or common stock, at 4.5% or 4.92%, respectively; and
		·		payable to the preferred stock investors prior to payment of any other dividend on any other shares of our capital stock.
	The Series C Preferred Stock also participates on an as-converted basis with respect to any dividends paid on the common stock.
	The Series C Preferred Stock is redeemable for a cash payment of an amount equal to 102% of the sum of the liquidation preference of $1,000 per share plus accrued but unpaid dividends.  If we call the Series C Preferred Stock for redemption, the holders have the right to convert their shares into a newly issued preferred stock identical in all respects to the Series C Preferred Stock except that such newly issued preferred stock will not bear a dividend.
	Upon the tenth anniversary of the initial issuance of the Series C Preferred Stock, we must redeem all of the Series C Preferred Stock for an amount equal to the Liquidation Preference plus accrued and unpaid dividends payable by us in cash or common stock at our election.  Issuance by us of common stock for such redemption is subject to the Equity Conditions and to the market value of the outstanding shares of common stock immediately prior to such redemption equaling at least $500 million.
	In the event of a change of control of Endeavour, we will be required to offer to redeem all of the Series C Preferred Stock for the greater of: (i) the amount equal to which such holder would be entitled to receive had the holder converted such Series C Preferred Stock into common stock; (ii) 115% of the sum of the Liquidation Preference plus accrued and unpaid dividends; and (iii) the amount resulting in an internal rate of return to such holder of 15% from the date of issuance of such Series C Preferred Stock through the date that Endeavour pays the redemption price for such shares.
	During 2011, holders of a portion of our Series C Preferred Stock converted 8,000 preferred shares, with a face value of $8 million, into 0.9 million shares of our common stock.
	Series B Preferred Stock
	In September 2002, we authorized and designated 500,000 shares of preferred stock, as Series B preferred stock par value $.001 per share (the “Series B Preferred Stock”).
	The Series B Preferred Stock is entitled to dividends of 8% of the original issuing price per share per annum, which are cumulative prior to any dividends on the common stock and on parity with the payment of any dividend or other distribution on any other series of preferred stock that has similar characteristics.  The holders of each share of Series B Preferred Stock are entitled to be paid out of available funds prior to any distributions to holders of common stock in the amount of $100.00 per outstanding share plus all accrued dividends.  We may, upon approval of our Board, redeem all or a portion of the outstanding shares of Series B Preferred Stock at a cost of the liquidation preference and all accrued and unpaid dividends.

StockBased_Compensation_Arrang

Stock-Based Compensation Arrangements	12 Months Ended
	Dec. 31, 2013
Stock-Based Compensation Arrangements [Abstract]	'
Stock-Based Compensation Arrangements	'
	Note 15 – Stock-Based Compensation Arrangements
	We grant restricted stock, performance units and stock options to employees and directors as incentive compensation.  The restricted stock and options generally vest over three years.  The vesting of these shares and options is dependent upon the continued service of the grantees with Endeavour.  Upon the occurrence of a change in control, each outstanding share of restricted stock and stock option will immediately vest.
	At December 31, 2013, total compensation cost related to nonvested awards not yet recognized was approximately $5.0 million and is expected to be recognized over a weighted average period of less than three years.  For the year ended December 31, 2013, we included approximately $1.2 million of stock-based compensation in capitalized G&A in property and equipment.
	Stock Options
	The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model.  We have not granted any options during the last three years.  Information relating to stock options, including notional stock options, is summarized as follows:
					Weighted			Weighted
			Number of		Average			Average
			Shares		Exercise			Contractual		Aggregate
			Underlying		Price per			Life in		Intrinsic
			Options		Share			Years		Value
	Balance outstanding January 1, 2013		188		$	6.72
	Exercised		-23			3.78
	Forfeited		-45			5.98
	Balance outstanding  - December 31, 2013		120		$	7.55		4.3		$	55
	Currently exercisable - December 31, 2013		120		$	7.55		4.3		$	55
	Information relating to stock options outstanding at December 31, 2013 is summarized as follows:
			Options Outstanding							Options Exercisable
	Range of Exercise Prices		Number of Options Outstanding		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price Per Share			Number Exercisable		Weighted Average Exercise Price Per Share
	Less than $5.00		37		5		$	3.78		37		$	3.78
	$5.00 - $8.00		—		—			—		—			—
	Greater than $8.00		83		4			9.23		83			9.23
	Total		120		4.3		$	7.55		120		$	7.55
	Restricted Stock
	At December 31, 2013, our employees and directors held 0.6 million restricted shares of our common stock that vest over the service period of up to three years.  The restricted stock awards were valued based on the closing price of our common stock on the measurement date, typically the date of grant, and compensation expense is recorded on a straight-line basis over the restricted share vesting period.
	Status of the restricted shares as of December 31, 2013 and the changes during the year ended December 31, 2013 are presented below:
						Weighted
						Average Grant
						Date Fair
			Number of			Value per
			Shares			Share
	Balance outstanding - January 1, 2013			754		$	10.11
	Granted			562			5.23
	Vested			-393			9.90
	Forfeited			-295			6.98
	Balance outstanding - December 31, 2013			628		$	7.44
	Total grant date fair value of shares vesting during the period		$	3,892
	Non-Cash stock-based compensation is recorded in G&A expenses or capitalized G&A as follows:
			Year Ended
			31-Dec-13
		2013			2012			2011
	G&A Expenses	$	3,607		$	4,641		$	2,988
	Capitalized G&A		1,236			1,634			1,051
	Total non-cash stock-based compensation	$	4,843		$	6,275		$	4,039
	Performance-Based Share Awards
	Certain of our officers and employees receive a target number of performance shares under individual Performance Unit Award Agreements.  The performance shares will be earned as the relative total shareholder return ranking is measured among a designated peer group at the end of a three-year performance period.  Payouts will be based on a predetermined schedule at the end of the performance period.  The shares issued may range from 0% to 200% of the number of Performance Units specified in the agreements. The fair value of each performance-based award is estimated on the date of grant using a Monte Carlo simulation model.
	Status of the performance-based share awards as of December 31, 2013 and the changes during the year ended December 31, 2013 are presented below:
					Weighted
					Average Grant
					Date Fair
			Number of		Value per
			Shares		Share
	Balance outstanding - January 1, 2013		358		$	16.72
	Granted		562			7.41
	Forfeited		-213			11.07
	Balance outstanding - December 31, 2013		707		$	11.01

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Note 16 – Earnings per Share
	Basic income (loss) per common share is computed by dividing net income (loss) to common stockholders by the weighted average number of common shares outstanding for the period.  Diluted income (loss) per share includes the effect of our outstanding stock options, warrants and shares issuable pursuant to convertible debt, convertible preferred stock and certain stock incentive plans under the treasury stock method, if including such instruments is dilutive.
	For each of the periods presented, shares associated with stock options, warrants, convertible debt, convertible preferred stock and certain stock incentive plans are not included when their inclusion would be antidilutive (i.e., reduce the net loss per share).  The common shares potentially issuable arising from these instruments excluded from weighted average diluted shares outstanding consisted of:
		For the Year Ended December 31,
		2013	2012	2011
	Options, warrants and stock-based compensation	7,981	2,111	111
	Convertible debt	12,041	11,532	11,078
	Convertible preferred stock	4,229	4,229	4,229
	Common shares potentially issuable	24,251	17,872	15,418

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Disclosures [Abstract]	'
Supplemental Cash Flow Information	'
	Note 17 – Supplementary Cash Flow Disclosures
	Cash paid during the period for interest and income taxes was as follows:
		Year Ended December 31,
		2013		2012		2011
	Interest paid	$	94,941	$	66,365	$	31,928
	Income taxes paid	$	57,132	$	426	$	9,427
	The cash paid for income taxes for the year ended December 31, 2013 includes $17 million related to 2012 that was not payable until 2013.  In addition, we paid $40 million in 2013 of which $21.5 million we expect to be refunded during 2014.
	Non-Cash Investing and Financing Transactions
	During 2012, we completed a nonmonetary exchange of our Bull Bayou Haynesville and Willow Springs Cotton Valley properties for all of J-W’s upstream and midstream interests in the Pennsylvania Marcellus area.  The exchanged properties were recorded on a carryover basis.
	As discussed in Note 12, in 2011, a combined 8,000 shares of our Series C Preferred Stock were converted into 0.9 million shares of our common stock.
	In 2013,  2012 and 2011, we recorded $7.1 million, $8.7 million and $12.8 million, respectively, in non-cash interest expense that was added to the principal balance of the 11.5% Convertible Bonds, the $50 million Subordinated Notes and the Senior Term Loan.

Financial_Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2013
Financial Instruments [Abstract]	'
Financial Instruments	'
	Note 18 – Financial Instruments
		31-Dec-13				31-Dec-12
		Fair Value		Carrying Value		Fair Value		Carrying Value
	Liabilities:
	Debt	$	868,406	$	870,878	$	869,488	$	859,506
	Derivative instruments		9,245		9,245		7,402		7,402
	The carrying amounts reflected in the consolidated balance sheets for cash and equivalents, short-term receivables and short-term payables approximate their fair value due to the short maturity of the instruments.  The fair values of commodity derivative instruments and interest rate swaps were determined based upon quotes obtained from brokers.  The fair values of long-term debt were determined based upon quotes obtained from brokers for our senior notes and discounted cash flows for our other debt.

Related_Parties_Transactions

Related Parties Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Note 19 – Related Party Transactions
	The Founding Partner and Chief Investment Officer, Ashok Nayyar, of Cyan Partners, LP became a member of our Board of Directors in September 2012.  In September 2012, we increased the amount available for borrowing under the Revolving Credit Facility to $125 million and borrowed $15 million of the additional capacity.  As of December 2013, we had utilized the full capacity under the Revolving Credit Facility.  In connection with the amendments to the Revolving Credit Facility during 2013, we agreed to pay a fee of $1.25 million to Cyan Partners, LP.  Mr. Nayyar resigned from our Board of Directors in March 2013.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Measurements [Abstract]	'
Fair Value Measurements	'
	Note 20 – Fair Value Measurements
	We measure the fair value of financial assets and liabilities on a recurring basis, defining fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.  The fair value is based on assumptions that market participants would use when pricing an asset or liability, including assumptions about risk and the risks inherent in valuation techniques and the inputs to valuations.  This includes not only the credit standing of counterparties involved and the impact of credit enhancements but also the impact of our own nonperformance risk on our liabilities.  Fair value measurements are classified and disclosed in one of the following categories:
	Level  1:Fair value is based on actively-quoted market prices, if available.
	Level  2:In the absence of actively-quoted market prices, we seek price information from external sources, including broker quotes and industry publications.  Substantially all of these inputs are observable in the marketplace during the entire term of the instrument, can be derived from observable data, or supported by observable levels at which transactions are executed in the marketplace.
	Level  3:If valuations require inputs that are both significant to the fair value measurement and less observable from objective sources, we must estimate prices based on available historical and near-term future price information and certain statistical methods that reflect our market assumptions.
	We apply fair value measurements to certain assets and liabilities including commodity derivative instruments and embedded derivatives relating to conversion and change in control features in certain of our debt instruments.  We seek to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.
	Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement.  The following table summarizes the valuation of our investments and financial instruments by pricing levels as of December 31, 2013 and 2012:
		Quoted Market Prices				Significant Other			Significant
		in Active Markets -				Observable Inputs -			Unobservable Inputs -			Total
		Level 1				Level 2			Level 3			Fair Value
	As of December 31, 2013:
	Embedded derivatives		$	—			$	—		$	-9,245		$	-9,245
	Total derivative liabilities		$	—			$	—		$	-9,245		$	-9,245
	As of December 31, 2012:
	Embedded derivatives			—				—			-7,402			-7,402
	Total derivative liabilities		$	—			$	—		$	-7,402		$	-7,402
	We use a derivative valuation model to derive the value of our embedded derivative features.  Key inputs into this valuation model are our current stock price, risk-free interest rates, the stock volatility and our implied credit spread. The first three aforementioned inputs are based on observable market data and are considered Level 2 inputs while the last two aforementioned inputs are unobservable and thus require management’s judgment and are considered Level 3 inputs.  A similar 5% decrease or increase in the stock volatility has an inverse effect to the change in the liability and would result in an approximately $0.5 million decrease or increase, respectively.
	The following is a reconciliation of changes in fair value of net derivative assets and liabilities classified as Level 3:
		Year Ended
		December 31,
		2013			2012
	Balance at beginning of period	$	-7,402		$	-15,858
	Total gains or losses (realized/unrealized)
	Included in earnings		-1,843			8,456
	Balance at end of period	$	-9,245		$	-7,402
	Changes in unrealized gains (losses) relating to derivatives assets and liabilities
	still held at the end of the period	$	-1,843		$	8,665
	Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
	Certain assets and liabilities are reported at fair value on a nonrecurring basis in our consolidated balance sheets.  The following methods and assumptions were used to estimate the fair values:
	Goodwill - Goodwill is tested annually at year end for impairment.  The first step of that process is to compare the fair value of the reporting unit to which goodwill has been assigned to the carrying amount of the associated net assets and goodwill.  Significant Level 3 inputs may be used in the determination of the fair value of the reporting unit, including present values of expected cash flows from operations.
	When we are required to measure fair value, and there is not a market observable price for the asset or liability, or a market observable price for a similar asset or liability, we generally utilize an income valuation approach.  This approach utilizes management’s best assumptions regarding expectations of projected cash flows, and discounts the expected cash flows using a commensurate risk adjusted discount rate.  Such evaluations involve a significant amount of judgment since the results are based on expected future events or conditions, such as sales prices; estimates of future oil and gas production; development and operating costs and the timing thereof; economic and regulatory climates and other factors.  Our estimates of future net cash flows are inherently imprecise because they reflect management’s expectation of future conditions that are often outside of management’s control.  However, assumptions used reflect a market participant’s view of long-term prices, costs and other factors, and are consistent with assumptions used in our business plans and investment decisions.

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2013
Derivative Instruments [Abstract]	'
Derivative Instruments	'
	Note 21 – Derivative Instruments
	We had embedded derivatives related to debt instruments at December 31, 2013 and 2012.  The fair market value of these derivative instruments is included in our balance sheet as follows:
		December 31,
		2013		2012
	Derivatives not designated as hedges:
	Embedded derivatives related to debt and equity instruments:
	Other liabilities - long-term	$	-9,245	$	-7,402
	The effect of the derivatives not designated as hedges on our results of operations was as follows:
		Year Ended December 31,
		2013		2012		2011
	Derivatives not designated as hedges:
	Oil and gas commodity derivatives:
	Unrealized gains (losses)	$	—	$	-3,524	$	-3,050
	Embedded derivatives related to debt and equity instruments:
	Unrealized gains (losses)	$	-1,843	$	8,665	$	11,428

Commitments_And_Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies [Abstract]	'
Commitments and Contingencies	'
	Note 22 – Commitments and Contingencies
	General
	The oil and gas industry is subject to regulation by federal, state and local authorities.  In particular, oil and gas production operations and economics are affected by environmental protection statutes, tax statutes and other laws and regulations relating to the petroleum industry.  We believe we are in compliance with all federal, state and local laws, regulations applicable to Endeavour and its properties and operations, the violation of which would have a material adverse effect on us or our financial condition.
	Commitments Related to Asset Retirement Obligations
	We have several agreements related to abandonment liabilities for certain of our U.K. oil and gas properties.  Under these agreements, unaffiliated third parties pledged cash to secure letters of credit covering certain of our abandonment liabilities and we agreed to reimburse the pledged cash in the event that the letters of credit are drawn and pledged cash is utilized to satisfy the commitment.  We have no cash collateral associated with these agreements and the commitments under the agreements are not recorded as liabilities.  The associated abandonment obligations are recorded in other long-term liabilities as part of our asset retirement obligations.  Fees and expenses related to these agreements are included in “Letter of credit fees” in other expenses on our condensed consolidated statement of operations.
	Decommissioning Security Agreements
	Procurement Agreement
	On January 9, 2013, we entered into a LOC Procurement agreement (the “Procurement Agreement”) with an unaffiliated third party entity, which matures on July 9, 2014.  The Procurement Agreement was entered into in connection with the unaffiliated third party’s entry into a credit support arrangement with a providing bank.  Pursuant to this credit support arrangement, the third party pledged cash, contributed by one of our shareholders, to secure letters of credit in the amount of $33.0 million.  The letters of credit secure decommissioning obligations in connection with certain of our U.K. license agreements.
	Under the Procurement Agreement, we agreed:
		·		to reimburse the third party in the event that the letters of credit are drawn and the pledged cash must be paid to the letter of credit provider;
		·		pay a quarterly fee computed at a rate of 9% per year on the outstanding amount of each letter of credit, along with an initial fee equal to 1% on the initial outstanding amount of each letter of credit;
		·		pay a fee of 2% on the outstanding amount of each letter of credit upon termination; and
		·		pay a fee of 0.65% per year on the aggregate balance of any outstanding letters of credit.
	The Procurement Agreement contains customary representations, warranties and non-financial covenants.  We also issued warrants to purchase a total of 1,000,000 shares of our common stock at an exercise price of $7.31 per share to the investor.  The warrants expire on January 9, 2018 and are subject to customary anti-dilution provisions.
	Concurrent with our entry into the LOC Procurement Agreement, we terminated the IVRRH Reimbursement Agreement dated May 23, 2012, which secured letters of credit.  Upon termination of the IVRRH Reimbursement Agreement, we paid all outstanding and accrued fees totaling approximately $3.8 million.
	Concurrent our entry into the Combined Procurement Agreement on January 24, 2014, the LOC Procurement Agreement was terminated, and we paid all outstanding and accrued fees totaling approximately $0.201 million.  Additional discussion of the Combined Procurement Agreement and the LOC Procurement Agreement termination can be found in Note 26 “Subsequent Events.”
	Reimbursement Agreements
	During the second quarter of 2012, we entered into two reimbursement agreements related to abandonment liabilities for certain of our U.K. oil and gas properties.  Under these agreements, unaffiliated third parties pledged cash to secure letters of credit covering certain of our abandonment liabilities and we agreed to reimburse the pledged cash in the event that the letters of credit are drawn and pledged cash is utilized to satisfy the commitment.  We have no cash collateral associated with the reimbursement agreements and the commitments under the reimbursement agreements are not recorded as liabilities.  The associated abandonment obligations are recorded in other long-term liabilities as part of our asset retirement obligations.  Fees and expenses related to the reimbursement agreements are included in other expenses on our condensed consolidated statement of operations.
	The first reimbursement agreement, covered approximately $33 million and was related to our decommissioning obligations at the IVRRH, Renee and Rubie (collectively “IVRRH”) fields where we are currently paying certain asset retirement costs.  In connection with this reimbursement agreement, we issued warrants to purchase two million shares of our common stock, with an exercise price of $10.50 per share, to the investors.  With the execution of the Procurement Agreement, on January 10, 2013, we terminated the IVRRH Reimbursement Agreement and paid all outstanding and accrued fees totaling approximately $3.8 million.
	The second reimbursement agreement covers approximately $120 million related to our decommissioning obligations for the Alba field (the “Alba Reimbursement Agreement) and matures on June 30, 2014.  We pay a fee of 13% per year, payable quarterly, computed based on the outstanding amount of each letter of credit.  Our obligations under the Alba Reimbursement Agreement are secured on a pari passu basis with our obligations under the Revolving Credit Facility by a first lien on substantially all of our assets.  As of December 31, 2013, we do not expect to begin decommissioning activities for the Alba field for many years.  The timing of decommissioning activities will be determined by the ultimate performance and life of the reservoir, which is not expected to occur until 2029 or later.
	With the execution of the Combined Procurement Agreement, on January 24, 2014, we terminated the Alba Reimbursement and paid all outstanding and accrued fees totaling approximately $  122 million.  Additional discussion of the Combined Procurement Agreement and the termination of the Alba Reimbursement Agreement can be found in Note 26 “Subsequent Events.”
	Terminated Acquisition of Marcellus Assets
	On July 17, 2011, we entered into agreements with SM Energy Company and certain other sellers named therein (“SM Energy”) for the purchase of oil and gas leases, producing properties, geophysical data, a pipeline and related assets in the Marcellus shale play in Pennsylvania for aggregate consideration of approximately $110 million (the “SM Purchase Agreements”).  We terminated the agreements on December 14, 2011, based on our conclusion that (i) the title defects we identified, after analyzing SM Energy’s responses to the notice of defects and valuation of the defects; and (ii) the condition of the pipeline was not in compliance with applicable regulatory standards.
	SM Energy filed a lawsuit against us in Texas state court on December 20, 2011 alleging that we breached the SM Purchase Agreements by terminating them and refusing to close on the transactions.  SM Energy seeks the award of unspecified actual damages, including costs and reasonable attorney’s fees, and specific performance.  On January 17, 2012, we filed an answer and counterclaim denying the allegations and seeking the return of our $6 million deposit, which we believe we are entitled to recover pursuant to the terms of the SM Purchase Agreements, and for the damages that we suffered as a result of SM Energy’s misrepresentations.  The case is presently scheduled for trial to commence in the second quarter of 2014.  We intend to contest the case vigorously.
	Operating Leases
	At December 31, 2013, we have leases for office space and equipment with lease payments as follows:
	2014		$	1,723
	2015			1,743
	2016			1,516
	2017			255
	Thereafter			—

Segment_And_Geographic_Informa

Segment And Geographic Information	12 Months Ended
	Dec. 31, 2013
Segment And Geographic Information [Abstract]	'
Segment And Geographic Information	'
	Note 23 – Segment and Geographic Information
	We have determined we have one reportable operating segment being the acquisition, exploration and development of oil and gas properties.  Our operations are conducted in geographic areas as follows:
		2013				2012				2011
		Revenue		Long-lived Assets			Revenue	Long-lived Assets		Revenue		Long-lived Assets
	United States	$	8,368	$	113,888	$	11,877	$	123,977	$	18,337	$	139,236
	United Kingdom		329,296		1,247,248		207,181		1,189,870		41,754		650,943
	Other		—		3,475		—		2,264		—		1,287
	Total	$	337,664	$	1,364,611	$	219,058	$	1,316,111	$	60,091	$	791,466
	Total International	$	329,296	$	1,250,723	$	207,181	$	1,192,134	$	41,754	$	652,230

Quarterly_Financial_Data

Quarterly Financial Data	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Quarterly Financial Data	'
	Note 24 – Quarterly Financial Data (Unaudited)
			First Quarter		Second Quarter		Third Quarter		Fourth Quarter
			2013 (1)
	Revenues		$	57,672	$	126,165	$	36,901	$	116,926
	Operating expenses			49,453		94,908		44,899		87,922
	Operating profit (loss)			8,219		31,257		-7,998		29,004
	Net loss to common stockholders			-14,502		-14,341		-40,341		-28,118
	Net loss  per common share - basic and diluted			-0.31		-0.3		-0.86		-0.6
			2012 (2)  (3)
	Revenues		$	15,166	$	23,003	$	83,275	$	97,615
	Operating expenses			33,867		41,359		64,174		59,857
	Operating profit (loss)			-18,701		-18,356		19,101		37,758
	Net loss to common stockholders			-35,718		-51,264		-34,158		-6,910
	Net loss  per common share - basic and diluted			-0.94		-1.31		-0.73		-0.15
	-1	Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.
	-2	Includes impairments of oil and gas properties of $15.7 million,  $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.
	-3	Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxes
		in prior periods that was not material to the current year operations.

Guarantor_Subsidiaries

Guarantor Subsidiaries	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Guarantor Subsidiaries	'
	Note 25 –  Guarantor Subsidiaries
	Certain of our wholly-owned domestic subsidiaries have, jointly and severally, fully and unconditionally guaranteed the 2018 Notes.  Pursuant to SEC regulations, we have presented in columnar format the condensed consolidating financial information for Endeavour International Corporation, the guarantor subsidiaries on a combined basis, and all non-guarantor subsidiaries on a combined basis.
	The subsidiary guarantees are unsecured obligations of each subsidiary guarantor and rank equally in right of payment with all senior indebtedness of that subsidiary guarantor and senior in right of payment to all subordinated indebtedness of that subsidiary guarantor.  The subsidiary guarantees are effectively subordinated to any secured indebtedness of the subsidiary guarantor with respect to the assets securing the indebtedness.  In addition, the subsidiary guarantees may be released in certain customary circumstances, including (i) the sale of all or substantially all of the properties or assets of a guarantor, (ii) the sale of the capital stock of a guarantor, (iii) the designation of a guarantor as an “Unrestricted Subsidiary,” (iv) upon legal defeasance of the 2018 Notes or satisfaction and discharge of the indentures governing the 2018 Notes, (v) upon the liquidation or dissolution of the guarantor or (vi) if the guarantor ceases to guarantee other of our indebtedness and ceases to be a material subsidiary, each of which is subject to important limitations in the indentures governing the 2018 Notes.
	Condensed consolidating financial statements for our guarantor subsidiaries and non-guarantor subsidiaries are presented in the following tables:
	As of December 31, 2013
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
	Cash and cash equivalents	$	-	$	2,417	$	32,325	$	-	$	34,742
	Accounts receivable		-		1,832		63,339		-		65,171
	Current receivables due from affiliates		853,900		20,783		45,982		-920,665		-
	Prepaid expenses and other		-		594		59,724		-		60,318
	Current Assets		853,900		25,626		201,370		-920,665		160,231
	Property, plant and equipment, net		-		87,313		984,838		-		1,072,151
	Goodwill		-		-		259,238		-		259,238
	Long-term receivables due from affiliates		-		500,000		8		-500,008		-
	Investments in subsidiaries		57,662		219,066		-		-276,728		-
	Other assets		20,518		6,056		6,648		-		33,222
	Total Assets	$	932,080	$	838,061	$	1,452,102	$	-1,697,401	$	1,524,842
	Accounts payable	$	-	$	1,214	$	36,819	$	-	$	38,033
	Deferred revenue		-		-		20,965		-		20,965
	Monetary production payment, current portion		-		-		74,167		-		74,167
	Current liabilities due to affiliates		648		899,853		20,171		-920,672		-
	Accrued expenses and other		27,474		3,352		57,799		-		88,625
	Current Liabilities		28,122		904,419		209,921		-920,672		221,790
	Long-term debt		678,850		-		192,028		-		870,878
	Long-term liabilities due to affiliates		-		-		500,000		-500,000		-
	Deferred taxes		-		-		146,213		-		146,213
	Monetary production payment, long-term portion		-		-		92,500		-		92,500
	Other liabilities		3,535		602		127,234		-		131,370
	Total Liabilities		710,507		905,021		1,267,896		-1,420,672		1,462,751
	Series C convertible preferred stock		43,703		-		-		-		43,703
	Stockholders' equity		177,870		-66,960		184,206		-276,728		18,388
	Total Liabilities and Equity	$	932,080	$	838,061	$	1,452,102	$	-1,697,401	$	1,524,842
	As of December 31, 2012
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
	Cash and cash equivalents	$	-	$	27,800	$	31,385	$	-	$	59,185
	Accounts receivable		-		2,695		43,486		-		46,181
	Current receivables due from affiliates		950,210		36,725		71,964		-1,058,899		-
	Prepaid expenses and other		-		508		38,559		-		39,067
	Current Assets		950,210		67,728		185,394		-1,058,899		144,433
	Property, plant and equipment, net		-		92,692		910,749		-		1,003,441
	Goodwill		-		-		262,764		-		262,764
	Long-term receivables due from affiliates		-		599,000		-		-599,000		-
	Investments in subsidiaries		57,662		120,058		-		-177,720		-
	Other assets		25,200		6,085		18,621		-		49,906
	Total Assets	$	1,033,072	$	885,563	$	1,377,528	$	-1,835,619	$	1,460,544
	Accounts payable	$	-	$	2,622	$	57,531	$	-	$	60,153
	Current maturities of debt		-		-		15,713		-		15,713
	Deferred revenue		-		-		-		-		-
	Monetary production payment deposit		-		-		-		-		-
	Current liabilities due to affiliates		34,509		987,664		36,726		-1,058,899		-
	Accrued expenses and other		27,548		1,517		61,035		-		90,100
	Current Liabilities		62,057		991,803		171,005		-1,058,899		165,966
	Long-term debt		676,413		-		167,380		-		843,793
	Long-term liabilities due to affiliates		-		-		599,000		-599,000		-
	Deferred taxes		-		-		159,959		-		159,959
	Monetary production payment, long-term portion		-		-		-		-		-
	Other liabilities		3,033		561		144,098		-		147,692
	Total Liabilities		741,503		992,364		1,241,442		-1,657,899		1,317,410
	Series C convertible preferred stock		43,703		-		-		-		43,703
	Stockholders' equity		247,866		-106,801		136,086		-177,720		99,431
	Total Liabilities and Equity	$	1,033,072	$	885,563	$	1,377,528	$	-1,835,619	$	1,460,544
	For the Year Ended December 31, 2013
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
Revenue	$	-	$	8,368	$	329,296	$	-	$	337,664
Operating expenses		-		7,399		98,045		-		105,444
DD&A expense		-		4,249		138,799		-		143,048
Impairment of oil and gas properties		-		9,566		-		-		9,566
G&A expenses		2,502		7,764		8,858		-		19,124
Income (loss) from Operations		-2,502		-20,610		83,594		-		60,482
Derivatives:
Unrealized losses		-503		-		-1,340		-		-1,843
Interest expense		-81,400		2,988		-86,105		60,001		-104,516
Letter of credit fees		-		-		-33,425		-		-33,425
Other income (expense)		-27		57,463		-7,170		-60,001		-9,735
Income (loss) before taxes		-84,432		39,841		-44,446		-		-89,037
Income tax expense		-		-		6,442		-		6,442
Net income (loss)		-84,432		39,841		-50,888		-		-95,479
Preferred stock dividends		1,823		-		-		-		1,823
Net income (loss) to common shareholders	$	-86,255	$	39,841	$	-50,888	$	-	$	-97,302
For the Year Ended December 31, 2012
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
Revenue	$	-	$	11,877	$	207,181	$	-	$	219,058
Operating expenses		-		6,968		51,568		-		58,536
DD&A expense		-		8,603		57,961		-		66,564
Impairment of oil and gas properties		-		53,072		-		-		53,072
G&A expenses		2,629		9,887		8,569		-		21,085
Income (loss) from Operations		-2,629		-66,653		89,083		-		19,801
Derivatives:
Unrealized gains (losses)		-705		-		5,846		-		5,141
Interest expense		-54,241		-951		-67,673		38,743		-84,122
Letter of credit fees		-		-		-21,903		-		-21,903
Loss on early extinguishment of debt		-		-		-21,661		-		-21,661
Other income (expense)		-		33,796		-4,307		-38,743		-9,254
Loss before taxes		-57,575		-33,808		-20,615		-		-111,998
Income tax expense		-		-		21,225		-6,997		14,228
Net loss		-57,575		-33,808		-41,840		6,997		-126,226
Preferred stock dividends		1,823		-		-		-		1,823
Net loss to common shareholders	$	-59,398	$	-33,808	$	-41,840	$	6,997	$	-128,049
For the Year Ended December 31, 2011
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
Revenue	$	-	$	18,337	$	41,754	$	-	$	60,091
Operating expenses		-		9,046		8,622		-		17,668
DD&A expense		-		11,490		14,988		-		26,478
Impairment of oil and gas properties		-		65,706		-		-		65,706
G&A expenses		2,198		10,789		4,866		-		17,853
Income (loss) from Operations		-2,198		-78,694		13,278		-		-67,614
Derivatives:
Unrealized gains (losses)		-2,642		-		11,020		-		8,378
Interest expense		-10,623		-3,964		-38,894		8,588		-44,893
Loss on early extinguishment of debt		-402		-		-		-		-402
Unrealized foreign currency gains (losses)		-		-	-	2,189	-	-	-	2,188
Other income (expense)		-211		-678		7,885		-8,588		-1,591
Loss before taxes		-16,076		-83,336		-4,522		-		-103,934
Income tax expense		-		3		27,058		-		27,061
Net loss		-16,076		-83,339		-31,580		-		-130,995
Preferred stock dividends		1,974		-		-		-		1,974
Net loss to common shareholders	$	-18,050	$	-83,339	$	-31,580	$	-	$	-132,969
For the Year Ended December 31, 2013
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-84,432	$	39,841	$	-50,888	$	—	$	-95,479
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		4,249		138,799		—		143,048
Impairment of oil and gas properties		—		9,566		—		—		9,566
Deferred tax benefit		—		—		-14,255		—		-14,255
Unrealized (gains) losses on derivatives		503		—		1,340		—		1,843
Amortization of non-cash compensation		622		—		—		2,984		3,606
Amortization of loan costs and discount		7,826		—		14,533		—		22,359
Non-cash interest expense		—		-12,958		20,040		—		7,082
Other		44		12,942		3,344		—		16,330
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		863		-19,854		—		-18,991
(Increase) decrease in other current assets		—		-14,252		15,576		—		1,324
Increase (decrease) in liabilities		—		-13,628		-24,395		19,038		-18,985
Net Cash Provided by (Used in)
Operating Activities		-75,437		26,623		84,240		22,022		57,448
Cash Flows From Investing Activities:
Capital expenditures		—		-15,111		-211,881		1,237		-225,755
Acquisitions, net of cash acquired		—		65		-2,852		—		-2,787
Proceeds from sales, net of cash		—		6,712		62		—		6,774
Net Cash Used in Investing Activities		—		-8,335		-214,670		1,237		-221,768
Cash Flows From Financing Activities:
Repayments of borrowings		—		—		—		—		—
Borrowings under debt agreements, net
of debt discount		—		—		—		—		—
Exercise of stock options		—		—		—		—		—
Borrowings from affiliates		—		—		—		—		—
Proceeds from issuance of MPP		—		—		175,000		—		175,000
Proceeds from issuance of common stock		—		—		—		—		—
Repayments of MPP		—		—		-8,333				-8,333
Payments for early extinguishment of debt		—		—		—		—		—
Financing costs paid		-700		-500		-35,296		11,286		-25,210
Intercompany cash management		77,874		-43,329		—		-34,545		—
Other financing		-1,737		157		—		—		-1,580
Net Cash Provided by (Used in)
Financing Activities		75,437		-43,672		131,371		-23,259		139,877
Net Change in Cash and Cash Equivalents		—		-25,383		940		—		-24,443
Cash and Cash Equivalents, Beginning
of Period		—		27,800		31,385		—		59,185
Cash and Cash Equivalents, End of Period	$	—	$	2,417	$	32,325	$	—	$	34,742
For the Year Ended December 31, 2012 (2)
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-57,575	$	-33,808	$	-41,840	$	6,997	$	-126,226
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		8,603		57,961		—		66,564
Impairment of oil and gas properties		—		53,072		—		—		53,072
Deferred tax benefit		—		—		-10,597		-6,997		-17,594
Unrealized (gains) losses on derivatives		705		—		-5,846		—		-5,141
Amortization of non-cash compensation		854		—		—		3,547		4,401
Amortization of loan costs and discount		6,908		5		7,266		—		14,179
Non-cash interest expense		445		—		8,239		—		8,684
Loss on early extinguishment of debt		—		—		21,661		—		21,661
Other		283		173		14,909		—		15,365
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		1,495		-25,814		—		-24,319
(Increase) decrease in other current assets		—		-9,223		8,631		—		-592
Increase (decrease) in liabilities		—		88,635		-21,617		-38,459		28,559
Net Cash Provided by (Used in)
Operating Activities		-48,380		108,952		12,953		-34,912		38,613
Cash Flows From Investing Activities:
Capital expenditures		—		-39,794		-207,131		—		-246,925
Acquisitions, net of cash acquired		—		-2,372		-236,482		—		-238,854
Proceeds from sales, net of cash		—		—		1,407		—		1,407
Issuance of note receivable to affiliate		—		-500,000		—		500,000		—
Increase in restricted cash		—		-50		-128		—		-178
Net Cash Used in Investing Activities		—		-542,216		-442,334		500,000		-484,550
Cash Flows From Financing Activities:
Repayments of borrowings		-32,457		—		-242,172		—		-274,629
Borrowings under debt agreements, net
of debt discount		538,860		—		115,163		—		654,023
Borrowings from affiliates		—		—		500,000		-500,000		—
Proceeds from issuance of MPP		—		—		—		—		—
Proceeds from issuance of common stock		60,805		—		—		—		60,805
Dividends paid		—		—		—		—		—
Payments for early extinguishment of debt		—		—		-7,248		—		-7,248
Financing costs paid		-24,141		—		-8,063		—		-32,204
Intercompany cash management		-493,026		458,114		—		34,912		—
Other financing		-1,661		—		—		—		-1,661
Net Cash Provided by (Used in)
Financing Activities		48,380		458,114		357,680		-465,088		399,086
Net Change in Cash and Cash Equivalents		—		24,849		-71,700		—		-46,851
Cash and Cash Equivalents, Beginning
of Period		—		2,951		103,085		—		106,036
Cash and Cash Equivalents, End of Period	$	—	$	27,800	$	31,385	$	—	$	59,185
For the Year Ended December 31, 2011 (2)
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-16,076	$	-83,339	$	-31,580	$	—	$	-130,995
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		11,490		14,988		—		26,478
Impairment of oil and gas properties		—		65,706		—		—		65,706
Deferred tax benefit		—		—		21,116		—		21,116
Unrealized (gains) losses on derivatives		2,642		—		-11,020		—		-8,378
Amortization of non-cash compensation		624		—		—		3,073		3,697
Amortization of loan costs and discount		1,049		-403		11,588		—		12,234
Non-cash interest expense		880		—		11,931		—		12,811
Loss on early extinguishment of debt		402		—		—		—		402
Other		-82		105		1,495		—		1,518
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		-1,597		1,066		—		-531
(Increase) decrease in other current assets		34		2,872		-16,234		—		-13,328
Increase (decrease) in liabilities		—		-39,135		11,732		-2,670		-30,073
Net Cash Provided by (Used in)
Operating Activities		-10,527		-44,301		15,082		403		-39,343
Cash Flows From Investing Activities:
Capital expenditures		—		-80,279		-84,783		—		-165,062
Acquisitions, net of cash acquired		—		-8,027		-25,048		—		-33,075
Increase in restricted cash		—		—		31,726		—		31,726
Net Cash Used in Investing Activities		—		-88,306		-78,105		—		-166,411
Cash Flows From Financing Activities:
Repayments of borrowings		-101,250		—		-1,975		—		-103,225
Borrowings under debt agreements, net
of debt discount		135,000		—		75,000		—		210,000
Proceeds from issuance of common stock		118,444		—		—		—		118,444
Dividends paid		—		—		—		—		—
Financing costs paid		-5,926		—		-5,475		—		-11,401
Intercompany cash management		-134,457		134,860		—		-403		—
Other financing		-1,284		-11		—		—		-1,295
Net Cash Provided by (Used in)
Financing Activities		10,527		134,849		67,550		-403		212,523
Net Change in Cash and Cash Equivalents		—		2,242		4,527		—		6,769
Cash and Cash Equivalents, Beginning
of Period		—		709		98,558		—		99,267
Cash and Cash Equivalents, End of Period	$	—	$	2,951	$	103,085	$	—	$	106,036
	-1		The $7.0 million adjustment reflects the correction of an immaterial error in deferred income taxes that was corrected to beginning stockholder’s equity as of January 1, 2010 in the separate financials of the non-guarantor subsidiaries but reflected in the current year statement of operations for Endeavour.
	-2		Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.”  There was no impact to Consolidated balances.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Note 26– Subsequent Events
	Term Loan Facility
	On January 24, 2014, we entered into a credit agreement for a $255 million senior secured first lien term loan facility (“Term Loan Facility”) whereby the lenders advanced $125 million and the Combined Procurement Agreement, discussed below.  The proceeds of the credit agreement were used to repay the outstanding amounts under our Revolving Credit Facility.  The repayment included a prepayment fee and accrued interest of approximately $2.0 million.  Subsequent to the repayment, the Revolving Credit Facility was terminated and all of the liens on our collateral obligations were released.  For additional discussion of the Revolving Credit Facility, see Note 10 “Debt Obligations.”
	The Term Loan Facility bears quarterly interest of LIBOR plus 7.00% annually (provided LIBOR equals at least 1.25% annually) and will mature on the earlier of (a) November 30, 2017 and (b) the date 91 days prior to the maturity of the company’s 5.5% convertible senior notes due 2016 and 11.5% convertible notes due 2016, provided the notes have not been converted, cancelled, extinguished, extended or refinanced prior to that date with a maturity date prior to March 1, 2018.
	Borrowings under the Term Loan Facility are unconditionally guaranteed by us and each of our current and future restricted subsidiaries.  The credit agreement contains covenants and provisions with respect to events of default that are substantially similar to the covenants in the indentures governing our 2018 Notes including, but not limited to, restrictions on our ability to: (i) pay distributions or repurchase or redeem the our capital stock or subordinated debt; (ii) make certain investments; (iii) incur additional indebtedness (iv) create or incur certain liens; (v) sell assets; (vi) consolidate, merge or transfer all or substantially all of our assets; (vii) enter into agreements that restrict distributions from our restricted subsidiaries to the Company; (viii) engage in transactions with affiliates; and (ix) create unrestricted subsidiaries.  In addition, the Term Loan Facility contains various financial and technical covenants, including:
		·	a minimum interest coverage ratio of 1.50:1.0;
		·	a maximum leverage ratio of 5.0:1.0; and
		·	a minimum asset coverage ratio of 2.0:1.0.
	Entry into Procurement Agreement
	On January 24, 2014, we also entered into a letter of credit procurement agreement (the “Combined Procurement Agreement”) with an unaffiliated third party (Payee), where we agreed to reimburse the Payee for any expense incurred by it in connection with the posting of cash collateral to secure letters of credit issued for our account in the amount of approximately £78 million (approximately $130 million as of January 24, 2014).  The letters of credit secure decommissioning obligations in connection with certain of our U.K. licences and have been outstanding and unchanged since 2006.  The Combined Procurement Agreement was entered into to replace the Alba Reimbursement Agreement and the LOC Procurement Agreement.
	Due to a change in the U.K. tax treatment for decommissioning, we have amended our Decommissioning Securities Agreement for the Alba field.  The new tax law, which allows companies to treat decommissioning on an after-tax basis (including PRT), enables us to reduce our current letter of credit amount on the Alba field from $120 million to approximately $55 million.
	Under the Combined Procurement Agreement, we agreed to pay a quarterly fee computed at a rate of LIBOR plus 7.00% per year (provided that LIBOR shall equal at least 1.25% per year) on aggregate balance of posted cash collateral.
	Similar to the Term Loan Facility, posted cash collateral under the Combined Procurement Agreement was issued with an original issue discount of 98.5% and matures on the earlier of (a) November 30, 2017 and (b) the date 91 days prior to the maturity of the Company’s 5.5% convertible senior notes due 2016 and 11.5% convertible notes due 2016, if such notes have not been converted, cancelled, extinguished, extended or refinanced in full prior to such date, with a resulting maturity date not earlier than March 1, 2018.  The Combined Procurement Agreement contains customary representations, warranties and non-financial covenants.  We and each of our current and future restricted subsidiaries have unconditionally guaranteed EEUK’s obligations under the Combined Procurement Agreement.
	Securities Purchase Agreement
	In February 2014, we entered into a securities purchase agreement (the “Securities Purchase Agreement”) relating to the issuance of up to $55 million in common stock, warrants and convertible notes.  We closed on an initial $30 million in late February and early March 2014, comprised of:
		·	2.9 million shares of our common stock;
		·	warrants to purchase 0.7 million shares of our common stock at an exercise price of $5.292 per share, expiring on February 28, 2019; and
		·	$17.5 million in aggregate principal of 6.5% convertible note (the “6.5% Convertible Notes).”
	The purchasers also have a  90-day option (the “Purchasers’ Option”) to purchase up to $25,000,000 of additional common stock, warrants and convertible debt on the same terms as the initial issuance.   To the extent the issuance of additional securities would result in the issuance of over 20% of the Company’s outstanding common stock, such issuance will be subject to the receipt of stockholder approval in accordance with applicable New York Stock Exchange rules.  The Purchasers’ Option may be extended in connection with the receipt of stockholder approval at the our 2014 annual meeting, in certain circumstances.
	The 6.5% Convertible Notes will mature one day following the earlier of (i) November 30, 2017 and (ii) 91 days prior to the maturity date of our outstanding 5.5% Convertible Senior Notes due 2016 and our 11.5% Convertible Bonds due 2016, if such securities have not been converted, cancelled or extinguished prior to such date or extended or refinanced in full prior to such date with a resulting maturity date not earlier than March 1, 2018.  Interest is payable on the 6.5% Convertible Notes on quarterly, commencing on June 1, 2014.  The notes are subject to customary events of default.
	The 6.5% Convertible Notes are:
		·	convertible at any time;
		·	convertible initially at a rate 214.5002 shares of our common stock per $1,000 principal amount of 6.5% Convertible Notes (equivalent to an initial conversion price of approximately $4.662 per share of our common stock);
		·	subject to certain anti-dilution adjustments;
		·	general unsecured and unsubordinated obligations; and
		·	equally ranked in right of payment with all of our existing and future unsubordinated indebtedness and senior in right of payment to any of our future indebtedness that is expressly subordinated to the 6.5% Convertible Notes.

Supplemental_Oil_And_Gas_Discl

Supplemental Oil And Gas Disclosures	12 Months Ended
	Dec. 31, 2013
Supplemental Oil And Gas Disclosures [Abstract]	'
Supplemental Oil And Gas Disclosures	'
	Note 27 - Supplemental Oil and Gas Disclosures (Unaudited)
	Capitalized Costs Relating to Oil and Gas Producing Activities
			United Kingdom			United States		Total
	December 31, 2013:
	Proved		$	1,043,927		$	40,741	$	1,084,668
	Unproved			295,083			73,578		368,661
	Total capitalized costs			1,339,010			114,319		1,453,329
	Accumulated depreciation, depletion and amortization			-355,366			-27,429		-382,795
	Net capitalized costs		$	983,644		$	86,890	$	1,070,534
	December 31, 2012:
	Proved		$	876,536		$	39,265	$	915,801
	Unproved			273,298			76,135		349,433
	Total capitalized costs			1,149,834			115,400		1,265,234
	Accumulated depreciation, depletion and amortization			-241,338			-24,269		-265,607
	Net capitalized costs		$	908,496		$	91,131	$	999,627
	Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities
				United Kingdom			United States		Total
	Year Ended December 31, 2013:
	Acquisition costs:
	Proved		$	—		$	—	$	—
	Unproved			2,323			463		2,786
	Exploration costs			39,202			11,644		50,846
	Development costs			146,685			3,088		149,773
	Total costs incurred		$	188,210		$	15,195	$	203,405
	Year Ended December 31, 2012:
	Acquisition costs:
	Proved		$	143,004		$	1,176	$	144,180
	Unproved			46,878			1,156		48,034
	Exploration costs			46,730			15,397		62,127
	Development costs			302,038			8,099		310,137
	Total costs incurred		$	538,650		$	25,828	$	564,478
	Year Ended December 31, 2011:
	Acquisition costs:
	Proved		$	2,595		$	—	$	2,595
	Unproved			46,107			2,840		48,947
	Exploration costs			51,820			75,880		127,700
	Development costs			79,898			10,560		90,458
	Total costs incurred		$	180,420		$	89,280	$	269,700
	Results of Operations for Oil and Gas Producing Activities
			United Kingdom	United States		Total
	Year Ended December 31, 2013:
	Revenues	$	329,296	$	8,368	$	337,664
	Production expenses		98,045		7,399		105,444
	DD&A		137,739		3,242		140,981
	Impairment of oil and gas properties		—		9,566		9,566
	Income tax expense (benefit)		57,977		-4,144		53,833
	Results of activities	$	35,535	$	-7,695	$	27,840
	Year Ended December 31, 2012:
	Revenues	$	207,181	$	11,877	$	219,058
	Production expenses		51,568		6,968		58,536
	DD&A		56,813		7,574		64,387
	Impairment of oil and gas properties		—		53,072		53,072
	Income tax expense (benefit)		61,256		-19,508		41,748
	Results of activities	$	37,544	$	-36,229	$	1,315
	Year Ended December 31, 2011:
	Revenues	$	41,754	$	18,337	$	60,091
	Production expenses		8,622		9,046		17,668
	DD&A		14,312		10,713		25,025
	Impairment of oil and gas properties		—		65,706		65,706
	Income tax expense (benefit)		11,104		-23,495		-12,391
	Results of activities	$	7,716	$	-43,633	$	-35,917
	Oil and Gas Reserves
	Proved reserves are estimated quantities of oil, gas and natural gas liquids that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Proved developed reserves are proved reserves that can reasonably be expected to be recovered through existing wells with existing equipment and operating methods.  The reserve volumes presented are estimates only and should not be construed as being exact quantities.  These reserves may or may not be recovered and may increase or decrease as a result of our future operations and changes in economic conditions.  Our oil and gas reserves were audited by independent reserve engineers at December 31, 2013,  2012 and 2011.  Total proved reserves decreased from 25.7 MMBOE at December 31, 2012 to 23.5 MMBOE at December 31, 2013, primarily due to production sold during the year.
		United Kingdom		United States		Total
Proved Oil Reserves (MBbls):
Proved reserves at January 1, 2011		3,664		59		3,723
Production		-373		-7		-380
Extensions and discoveries		303		—		303
Revisions of previous estimates		466		-11		455
Proved reserves at December 31, 2011		4,060		41		4,101
Production		-1,994		-3		-1,997
Purchases of reserves		11,071		—		11,071
Sales of reserves in place		—		-19		-19
Extensions and discoveries		1,992		—		1,992
Revisions of previous estimates		-1,396		-13		-1,409
Proved reserves at December 31, 2012		13,733		6		13,739
Production		-3,017		-1		-3,018
Purchases of reserves		—		—		—
Sales of reserves in place		—		—		—
Extensions and discoveries		—		—		—
Revisions of previous estimates		1,624		-3		1,621
Proved reserves at December 31, 2013		12,340		2		12,342
Proved Developed Oil Reserves (MBbls):
At December 31, 2011		1,270		41		1,311
At December 31, 2012		5,261		6		5,267
At December 31, 2013		5,659		2		5,661
		United Kingdom		United States		Total
Proved Gas Reserves (MMcf):
Proved reserves at January 1, 2011		56,177		31,777		87,954
Production		-94		-5,076		-5,170
Purchases of reserves		90		—		90
Extensions and discoveries		—		46,100		46,100
Revisions of previous estimates		-5,450		-11,823		-17,273
Proved reserves at December 31, 2011		50,723		60,978		111,701
Production		-91		-5,206		-5,297
Purchases of reserves		1,409		998		2,407
Sales of reserves in place		—		-5,213		-5,213
Extensions and discoveries		473		—		473
Revisions of previous estimates		4,387		-36,867		-32,480
Proved reserves at December 31, 2012		56,901		14,690		71,591
Production		-1,194		-2,636		-3,830
Purchases of reserves		—		—		—
Sales of reserves in place		—		-4,200		-4,200
Extensions and discoveries		—		—		—
Revisions of previous estimates		-309		3,921		3,612
Proved reserves at December 31, 2013		55,398		11,775		67,173
Proved Developed Gas Reserves (MMcf):
At December 31, 2011		795		22,704		23,499
At December 31, 2012		3,147		14,690		17,837
At December 31, 2013		18,384		9,792		28,176
		United Kingdom		United States		Total
Proved Reserves (MBOE):
Proved reserves at January 1, 2011		13,027		5,355		18,382
Production		-389		-853		-1,242
Extensions and discoveries		—		7,683		7,683
Purchase of proved reserves, in place		318		—		318
Revisions of previous estimates		-442		-1,981		-2,423
Proved reserves at December 31, 2011		12,514		10,204		22,718
Production		-2,009		-871		-2,880
Extensions and discoveries		2,071		—		2,071
Purchase of proved reserves, in place		11,306		166		11,472
Sale of reserves		—		-888		-888
Revisions of previous estimates		-665		-6,157		-6,822
Proved reserves at December 31, 2012		23,217		2,454		25,671
Production		-3,216		-440		-3,656
Extensions and discoveries		—		—		—
Purchase of proved reserves, in place		—		—		—
Sale of reserves		—		-700		-700
Revisions of previous estimates		1,572		651		2,223
Proved reserves at December 31, 2013		21,573		1,965		23,538
Proved Developed Reserves (MBOE):
At December 31, 2011		1,402		3,825		5,227
At December 31, 2012		5,785		2,454		8,239
At December 31, 2013		8,723		1,634		10,357
Standardized Measure of Discounted Future Net Cash Flows
Future cash inflows and future production and development costs are determined by applying average 12-month pricing for the year.  Oil, gas and condensate prices are escalated only for fixed and determinable amounts under provisions in some contracts.  Estimated future income taxes are computed using current statutory income tax rates where production occurs.  The resulting future net cash flows are reduced to present value amounts by applying a 10% annual discount factor.
At December 31, 2013 and 2012, the prices used to determine the estimates of future cash inflows  were as follows:
		December 31,
		2013				2012
		Oil		Gas		Oil	Gas
		($/Barrel)		($/Mcf)		($/Barrel)	($/Mcf)
United Kingdom		104.45		10.38		111.13	9.34
United States		97.71		2.94		94.71	2.75
Estimated future cash inflows are reduced by estimated future development, production, abandonment and dismantlement costs based on year-end cost levels, assuming continuation of existing economic conditions, and by estimated future income tax expense.  Income tax expense, both U.S. and foreign, is calculated by applying the existing statutory tax rates, including any known future changes, to the pretax net cash flows giving effect to any permanent differences and reduced by the applicable tax basis.  The effect of tax credits is considered in determining the income tax expense.
The standardized measure of discounted future net cash flows is not intended to present the fair market value of our oil and gas reserves.  An estimate of fair value would also take into account, among other things, the recovery of reserves in excess of proved reserves, anticipated future changes in prices and costs, an allowance for return on investment and the risks inherent in reserve estimates.
Standardized Measure of Discounted Future Net Cash Flows
		United Kingdom			United States		Total
December 31, 2013:
Future cash inflows		$	1,862,137			34,852	$	1,896,989
Future production costs			-571,347			-12,202		-583,549
Future development costs			-593,958			-605		-594,563
Future income tax expense			-133,495			—		-133,495
Future net cash flows (undiscounted)			563,337			22,045		585,382
Annual discount of 10% for estimated timing			43,152			6,548		49,700
Standardized measure of future net cash flows		$	520,185			15,497	$	535,682
December 31, 2012:
Future cash inflows		$	2,035,208		$	31,258	$	2,066,466
Future production costs			-568,414			-10,101		-578,515
Future development costs			-581,277			-896		-582,173
Future income tax expense			-277,436			—		-277,436
Future net cash flows (undiscounted)			608,081			20,261		628,342
Annual discount of 10% for estimated timing			122,780			6,584		129,364
Standardized measure of future net cash flows		$	485,301		$	13,677	$	498,978
Principal Sources of Change in the Standardized Measure of Discounted Future Net Cash Flows
		2013			2012		2011
Standardized measure, beginning of period		$	498,978		$	264,872	$	111,297
Net changes in prices and production costs			-33,792			-33,520		147,776
Future development costs incurred			140,436			172,462		76,721
Net changes in estimated future development costs			88,008			-193,359		-9,261
Revisions of previous quantity estimates			—			-56,525		-36,421
Extensions and discoveries			-132,092			102,386		68,452
Accretion of discount			78,151			42,589		18,801
Changes in income taxes, net			104,891			-74,778		-136,157
Sale of oil and gas produced, net of production costs			-232,220			-165,547		-44,556
Purchased reserves			—			457,033		26,340
Sales of reserves in place			-4,074			-6,971		—
Change in production, timing and other			27,396			-9,664		41,880
Standardized measure, end of period		$	535,682		$	498,978	$	264,872

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation and Use of Estimates
	The accompanying financial statements have been prepared on the accrual basis of accounting in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) and have been presented on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business.  In the opinion of management, all normal recurring adjustments considered necessary for a fair presentation have been included in these financial statements.  Certain amounts for prior periods have been reclassified to conform to the current presentation.
	These accounting principles require management to use estimates, judgments and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported herein.  While management regularly reviews its estimates, actual results could differ from those estimates.
	Management believes it is reasonably possible that the following material estimates affecting the financial statements could change in the coming year:
		·	estimates of proved oil and gas reserves;
		·	estimates as to the expected future cash flow from proved oil and gas properties;
		·	estimates of future dismantlement and restoration costs;
		·	estimates of fair values used in purchase accounting; and
		·	estimates of the fair value of derivative instruments.
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying consolidated financial statements include all of the accounts of Endeavour and our consolidated subsidiaries.  All significant intercompany accounts and transactions have been eliminated.  Investments in entities over which we have significant influence, but not control, are carried at cost adjusted for equity in earnings or (losses) and distributions received.
Cash And Cash Equivalents	'
	Cash and Cash Equivalents
	We consider all highly liquid instruments with an original maturity of 90 days or less at the time of purchase to be cash equivalents.
Restricted Cash	'
	Restricted Cash
	Restricted cash has historically included amounts held in escrow for drilling rig commitments, as collateral for lines of credit, and for acquisitions.
Inventories	'
	Inventories
	Materials and supplies and oil inventories are valued at the lower of cost or market value (net realizable value).  Our inventories are stated on an average cost basis.
Full Cost Accounting For Oil And Gas Operations	'
	Full Cost Accounting for Oil and Gas Operations
	Under the full cost method of accounting for oil and gas activities, all acquisition, exploration and development costs incurred for the purpose of finding oil and gas, are capitalized and accumulated in pools on a country-by-country basis.  Capitalized costs include the cost of drilling and equipping productive wells, such as the estimated costs of dismantling and abandoning these assets, dry hole costs, lease acquisition costs, seismic and other geological and geophysical costs, delay rentals, costs related to such activities, certain directly-related employee costs and a portion of interest expense.   Employee costs associated with production and other operating activities and general corporate activities are expensed in the period incurred.
	Capitalized costs are limited on a country-by-country basis (the ceiling test).  Under the ceiling test, if the capitalized cost of the full cost pool, net of deferred taxes, exceeds the ceiling limitation, the excess is charged as an impairment expense.  The ceiling test limitation is calculated as the present value, discounted 10%, of:
		·	the future net cash flows related to estimated production of proved reserves, utilizing the average, first-day-of-the-month price for commodities;
		·	the effect of derivative instruments that qualify as cash flow hedges;
		·	the lower of cost or estimated fair value of unproved properties; and
		·	the expected income tax effects of the above items.
	We utilize a single cost center for each country where we have operations for amortization purposes.  Any sales or other conveyances of properties are treated as adjustments to the cost of oil and gas properties with no gain or loss recognized unless the operations are suspended in the entire cost center or the conveyance is significant in nature.    Proved properties are amortized on a country-by-country basis using the units of production method (“UOP”).  The amortization base in the UOP calculation includes the sum of proved property, net of accumulated DD&A, estimated future development costs (future costs to access and develop proved reserves), and asset retirement costs, less related salvage value.
	Unproved property costs include the costs associated with unevaluated properties and properties under development and are not initially included in the full cost amortization base (where proved reserves exist) until the project is evaluated.  These costs include unproved leasehold acreage, seismic data, wells and production facilities in progress and wells pending determination, together with interest costs capitalized for these projects. Seismic data costs are associated with specific unevaluated properties where the seismic data is acquired for the purpose of evaluating acreage or trends covered by a leasehold interest owned by us.
	Significant unproved properties are assessed periodically for possible impairment or reduction in value.  If a reduction in value has occurred, these property costs are considered impaired and are transferred to the related full cost pool.  Geological and geophysical costs included in unproved properties are transferred to the full cost amortization base along with the associated leasehold costs on a specific project basis. Costs associated with wells in progress and wells pending determination are transferred to the amortization base once a determination is made whether or not proved reserves can be assigned to the property.  Costs of dry holes are transferred to the amortization base immediately upon determination that the well is unsuccessful.  Unproved properties whose acquisition costs are not individually significant are aggregated and the portion of such costs estimated to be ultimately nonproductive, based on experience, are amortized to the full cost pool over an average holding period.
	In countries where the existence of proved reserves has not yet been determined, unevaluated property costs remain capitalized in unproved property cost centers until proved reserves have been established, exploration activities cease or impairment and reduction in value occurs.  If exploration activities result in the establishment of a proved reserve base, amounts in the unproved property cost center are reclassified as proved properties and become subject to amortization and the application of the ceiling test.  When it is determined that the value of unproved property costs have been permanently diminished (in part or in whole) based on the impairment evaluation and future exploration plans, the unproved property cost centers related to the area of interest are impaired, and accumulated costs charged against earnings.
Other Property And Equipment	'
	Other Property and Equipment
	Other oil and gas assets, computer equipment and furniture and fixtures are recorded at cost, less accumulated depreciation.  The assets are depreciated using the straight-line method over their estimated useful lives of two to five years.
Capitalized Interest	'
	Capitalized Interest
	We capitalize interest on expenditures for significant exploration and development projects while activities are in progress to bring the assets to their intended use.  Capitalized interest is calculated by multiplying our weighted-average interest rate on debt by the amount of qualifying costs and is limited to gross interest expense.
Business Combinations	'
	Business Combinations
	Assets and liabilities acquired through a business combination are recorded at estimated fair value.  We use all available information to make these fair value determinations, including information commonly considered by our engineers in valuing individual oil and gas properties and sales prices for similar assets.  Estimated deferred taxes are based on available information concerning the tax basis of the acquired company’s assets and liabilities and carry forwards at the merger date.
	Any excess of the acquisition cost of the acquired business over the fair value amounts assigned to assets and liabilities is recorded as goodwill.  The amount of goodwill recorded in any particular business combination can vary significantly depending upon the fair values attributed to assets acquired and liabilities assumed relative to the total acquisition cost.
Goodwill And Intangible Assets	'
	Goodwill and Intangible Assets
	We assess the carrying amount of goodwill and other indefinite-lived intangible assets by testing the asset for impairment annually at year-end, or more frequently if events or changes in circumstances indicate that the asset might be impaired.  The impairment test requires allocating goodwill and all other assets and liabilities to reporting units.  The fair value of each reporting unit is determined and compared to the book value of the reporting unit.  An impairment loss is recognized to the extent that the carrying amount exceeds the reporting unit’s fair value.
Dismantlement, Restoration And Environmental Costs	'
	Dismantlement, Restoration and Environmental Costs
	We recognize liabilities for asset retirement obligations associated with tangible long-lived assets, such as producing well sites, offshore production platforms, and natural gas processing plants, with a corresponding increase in the related long-lived asset.  The asset retirement cost is depreciated along with the property and equipment in the full cost pool.  The asset retirement obligation is recorded at fair value and accretion expense, recognized over the life of the property, increases the liability to its expected settlement value.  If the fair value of the estimated asset retirement obligation changes, an adjustment is recorded for both the asset retirement obligation and the asset retirement cost.
Revenue Recognition	'
	Revenue Recognition
	We use the entitlements method to account for sales of gas production.  We may receive more or less than our entitled share of production.  Under the entitlements method, if we receive more than our entitled share of production, the imbalance is treated as a liability at the market price at the time the imbalance occurred.  If we receive less than our entitled share, the imbalance is recorded as an asset at the lower of the current market price or the market price at the time the imbalance occurred.  Oil revenues are recorded when production is transported by pipeline or the production is shipped out of our storage tanks.  Oil revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred, title has transferred and collectability of the revenue is probable.
Significant Customers	'
	Significant Customers
	Our sales in the U.K. are to a limited number of customers.  For the year ended December 31, 2013, our sales to Shell U.K. Limited accounted for more than 10% of revenue.  Our sales in the U.S. are sold through our arrangements with the operators of the fields, with the majority of the sales being to J-W Operating Company.
Derivative Instruments And Hedging Activities	'
	Derivative Instruments and Hedging Activities
	From time to time, we may utilize derivative financial instruments to hedge cash flows from operations or to hedge the fair value of financial instruments.  We also have embedded derivatives related to our debt instruments and convertible preferred stock.
	We may use derivative financial instruments with respect to a portion of our oil and gas production or a portion of our variable rate debt to achieve a more predictable cash flow by reducing our exposure to price fluctuations.  These transactions are likely to be swaps, collars or options and to be entered into with major financial institutions or commodities trading institutions.  Derivative financial instruments are intended to:
		·	reduce our exposure to declines in the market prices of crude oil and natural gas that we produce and sell;
		·	reduce our exposure to increases in interest rates, and
		·	manage cash flows in support of our annual capital expenditure budget.
	We record all derivatives at fair market value in our Consolidated Balance Sheets at the end of each period.  The accounting for the fair market value, and the changes from period to period, depends on the intended use of the derivative and the resulting designation.  This evaluation is determined at each derivative’s inception and begins with the decision to account for the derivative as a hedge, if applicable.  The accounting for changes in the fair value of a derivative instrument that is not accounted for as a hedge is included in other (income) expense as an unrealized gain or loss.  At December 31, 2013 and 2012, we had  no outstanding derivatives that were accounted for as a hedge.
Conscentrations of Credit and Market Risk	'
	Concentrations of Credit and Market Risk
	Financial instruments that potentially subject us to concentrations of credit risk consist principally of cash deposits at financial institutions.  At various times during the year, we may exceed the federally insured limits.  To mitigate this risk, we place our cash deposits only with high credit quality institutions.  Management believes the risk of loss is minimal.
	As an independent oil and gas producer, our revenue, profitability and future rate of growth are substantially dependent upon prevailing prices for oil and gas, which are dependent upon numerous factors beyond our control, such as economic, political and regulatory developments and competition from other sources of energy.  The energy markets have historically been very volatile, and there can be no assurance that oil and gas prices will not be subject to wide fluctuations in the future.  A substantial or extended decline in oil and gas prices could have a material adverse effect on our financial position, results of operations, cash flows and our access to capital and on the quantities of oil and gas reserves that may be economically produced.
Foreign Currency Translation	'
	Foreign Currency Translation
	The U.S. dollar is the functional currency for all of our existing operations, as a majority of all revenue and financing transactions in these operations are denominated in U.S. dollars.  For foreign operations with the U.S. dollar as the functional currency, monetary assets and liabilities are remeasured into U.S. dollars at the exchange rate on the balance sheet date.  Nonmonetary assets and liabilities are translated into U.S. dollars at historical exchange rates.  Income and expense items are translated at exchange rates prevailing during each period.  Adjustments are recognized currently as a component of foreign currency gain or loss and deferred income taxes.  To the extent that business transactions are not denominated in U.S. dollars, we are exposed to foreign currency exchange rate risk.
Income Taxes	'
	Income Taxes
	We use the liability method of accounting for income taxes under which deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities, and their respective tax bases.  Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled.  The effect on deferred tax assets and liabilities of a change in tax rates is recognized as part of the provision for income taxes in the period that includes the enactment date.  Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion of, or all of, the deferred tax assets will not be realized.
Share-Based Payments	'
	Share-Based Payments
	We recognize all share-based payments to employees, including grants of employee stock options, based on their fair values.  The share-based compensation cost is measured at the grant date, based on the calculated fair value of the award, and is recognized as general and administrative expense over the employee’s requisite service period (generally the vesting period of the equity award).
	It is our policy to use authorized but unissued shares of stock when stock options are exercised.  At December 31, 2013, we had approximately 1.8 million additional shares available for issuance pursuant to our existing stock incentive plans.

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Schedule Of Purchase Price Allocation	'
	Purchase Price	$	255,400
	Purchase Price adjustments for estimated after-tax cash flows from the acquired asset and
	interest costs from effective date of January 1, 2011 to closing		-25,823
	Total purchase price	$	229,577
	Allocation of purchase price:
	Property and equipment	$	191,507
	Goodwill		47,353
	Current assets		24,632
	Current liabilities		-12,815
	Deferred tax liability		-6,999
	Other long-term liabilities		-14,101
	Total purchase price	$	229,577

Recovered_Sheet1

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Prepaid Expenses And Other Current Assets [Abstract]	'
Schedule Of Prepaid Expenses And Other Current Assets	'
		December 31,
		2013		2012
	Prepaid well and drilling costs	$	24	$	2,843
	Prepaid insurance		3,707		3,330
	Inventory		5,117		5,127
	Deferred tax asset		26,583		26,161
	Deferred financing costs - current portion		22,134		—
	Other		2,753		1,606
		$	60,318	$	39,067

Property_And_Equipment_Tables

Property And Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property and Equipment [Abstract]	'
Schedule Of Property And Equipment	'
		December 31,
		2013			2012
	Oil and gas properties under the full cost method:
	Subject to amortization	$	1,084,669		$	915,801
	Not subject to amortization:
	Acquired in 2013		52,748			-
	Acquired in 2012		138,641			141,837
	Acquired in 2011		99,740			107,510
	Acquired prior to 2011		77,531			100,086
			1,453,329			1,265,234
	Computers, furniture and fixtures		8,734			8,863
	Total property and equipment		1,462,063			1,274,097
	Accumulated depreciation, depletion and amortization		-389,912			-270,656
	Net property and equipment	$	1,072,151		$	1,003,441
Oil And Gas Properties Not Subject To Amortization	'
	Costs Incurred in the Year Ended December 31,
			2013			2012		2011		Prior to 2011		Total
	Acquisition costs		$	384		$	48,409	$	48,995	$	35,409	$	133,197
	Exploration costs			35,584			77,200		47,656		42,122		202,562
	Capitalized interest			16,780			13,032		3,089		—		32,901
	Total oil and gas properties not
	subject to amortization		$	52,748		$	138,641	$	99,740	$	77,531	$	368,660

Goodwill_Tables

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill [Abstract]	'
Schedule Of Goodwill	'
		December 31,
		2013		2012
	Balance at beginning of year	$	262,764	$	211,886
	Purchase price adjustment		-3,526		50,878
	Balance at end of year	$	259,238	$	262,764

Other_Assets_Tables

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Other Assets [Abstract]	'
Schedule Of Other Long-Term Assets	'
		2013		2012
	Debt issuance costs	$	20,856	$	30,599
	Deferred issuance costs related to reimbursement agreements		—		11,290
	Deposits related to SM Energy litigation		6,000		6,000
	Other		6,366		2,017
		$	33,222	$	49,906

Accrued_Expenses_And_Other_Cur1

Accrued Expenses And Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Accrued Expenses And Other Current Liabilities [Abstract]	'
Schedule Of Accrued Expenses And Other Current Liabilities	'
		December 31,
		2013		2012
	Foreign taxes payable	$	2,875	$	18,989
	Accrued interest		29,512		25,932
	Preferred dividends		1,774		1,617
	Accrued compensation		3,210		1,882
	Current portion of asset retirement obligations		48,895		36,255
	Other		2,359		5,425
		$	88,625	$	90,100

Debt_Obligations_Tables

Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Obligations [Abstract]	'
Schedule Of Debt	'
		2013		2012
	Senior notes, 12% fixed rate, due 2018	$	554,000	$	554,000
	Convertible senior notes, 5.5% fixed rate, due 2016		135,000		135,000
	Revolving credit facility, 13% fixed rate, due 2014		115,163		115,163
	Convertible bonds, 11.5% until March 31, 2014 and 7.5% thereafter, due 2016		78,437		70,029
			882,600		874,192
	Less:  debt discount, net of premium		-11,722		-14,686
	Less:  current maturities		—		-15,713
	Long-term debt	$	870,878	$	843,793
Schedule Of Debt Maturities	'
	2014 (balance repaid in full with proceeds from the Term Loan Facility)	$	115,163
	2015		—
	2016		213,437
	2017		—
	2018		554,000
	Thereafter		—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Taxes [Abstract]	'
Schedule Of Components Of Income Tax Expense (Benefit)	'
	(Amounts in thousands)	U.K.			U.S.			Other		Total
	Year Ended December 31, 2013:
	Net income (loss) before taxes	$	-35,273		$	-44,591		$	-9,173	$	-89,037
	PRT tax current expense		20,667			—			—		20,667
	PRT tax deferred benefit		-13,978			—			—		-13,978
	PRT tax expense		6,689			—			—		6,689
	Corporate current expense		—			—			30		30
	Corporate deferred benefit		-277			—			—		-277
	Corporate tax expense (benefit)		-277			—			30		-247
	Total tax expense		6,412			—			30		6,442
	Net income (loss) after taxes	$	-41,685		$	-44,591		$	-9,203	$	-95,479
	Year Ended December 31, 2012:
	Net income (loss) before taxes	$	-22,959		$	-91,383		$	2,344	$	-111,998
	PRT tax current expense		31,796			—			—		31,796
	PRT tax deferred benefit		-14,823			—			—		-14,823
	PRT tax expense		16,973			—			—		16,973
	Corporate current expense		—			—			26		26
	Corporate deferred benefit		-11,358			—			—		-11,358
	Deferred tax expense related to U.K. tax law change		8,587			—			—		8,587
	Corporate tax expense (benefit)		-2,771			—			26		-2,745
	Total tax expense		14,202			—			26		14,228
	Net income (loss) after taxes	$	-37,161		$	-91,383		$	2,318	$	-126,226
	Year Ended December 31, 2011:
	Net income (loss) before taxes	$	-9,806		$	-99,409		$	5,281	$	-103,934
	PRT tax current expense		5,926	—		—			—		5,926
	PRT tax deferred benefit		-373			—			—		-373
	PRT tax expense		5,553			—			—		5,553
	Corporate current expense		—			4			15		19
	Corporate deferred benefit		-3,935			—			—		-3,935
	Deferred tax expense related to U.K. tax law change		25,424			—			—		25,424
	Corporate tax expense		21,489			4			15		21,508
	Total tax (benefit) expense		27,042			4			15		27,061
	Net income (loss) after taxes	$	-36,848		$	-99,413		$	5,266	$	-130,995
Schedule Of Effective Income Tax Rate Reconciliation	'
		Year Ended December 31,
		2013			2012			2011
	Federal income tax benefit at statutory rate	$	-31,163		$	-39,199		$	-36,378
	Taxation of foreign operations		21,998			5,859			3,254
	Effect of out-of-period adjustment		—			6,997			—
	Change in valuation allowance – U.S.		15,343			30,329			24,604
	U.K. tax increase from tax law and rate changes		—			8,587			25,424
	Deemed foreign dividend of wholly owned subsidiaries		—			—			8,572
	Disallowed executive compensation		247			1,655			1,585
	Other		17			—			—
	Total Income Tax Expense	$	6,442		$	14,228		$	27,061
	Effective Income Tax Rate		-7%			-13%			-26%
Schedule Of Deferred Tax Assets And Liabilities	'
		2013			2012
	Deferred tax asset:
	Deferred compensation	$	2,401		$	2,268
	Asset retirement obligation		84,941			87,787
	Net operating loss and capital loss carryforward		423,374			334,121
	Unrealized loss on embedded derivative instruments		1,265			1,084
	Property, plant and equipment		14,086			19,596
	Inventory / other		2,185			8,089
	Total deferred tax assets		528,252			452,945
	Less valuation allowance		-103,171			-84,691
	Total deferred tax assets after valuation allowance		425,081			368,254
	Deferred tax liability:
	Property, plant and equipment		-526,274			-478,719
	Petroleum revenue tax, net of tax benefit		-17,967			-22,703
	Debt discount		-471			-630
	Total deferred tax liabilities		-544,712			-502,052
	Net deferred tax liability	$	-119,631		$	-133,798
Schedule Of Tax Attributes Available To Reduce Future Income Taxes	'
				As of December 31,
				2013					2012
		Types of Tax Attributes		Years of Expiration		Carry-forward Amount			Years of Expiration	Carry-forward Amount
	U.K.
	Corporate tax	NOL		Indefinite		$	638,466		Indefinite	$	500,789
	Supplemental Corporate tax	NOL		Indefinite			455,318		Indefinite		378,602
	U.S.
	Corporate Income tax	NOL		2023 - 2033			232,745		2023 - 2032		177,206
	State Income tax	NOL		2014 - 2033			83,613
	Capital gains tax	Capital loss		2015			1,848		2015		1,848
Schedule Of Change In Unrecognized Tax Benefits	'
			Year Ended
			December 31,
			2013			2012			2011
	Balance at the beginning of the year	$	6,820		$	-		$	-
	Increase in unrecognized tax benefits from current period tax position		-			6,820			-
	Balance at the end of the year	$	6,820		$	6,820		$	-
Schedule Of Tax Years Subject To Examination	'
	Tax Jurisdiction
	U.K.	2012 - 2013
	All others	2010 - 2013

Monetary_Production_Payment_Ta

Monetary Production Payment (Tables)	12 Months Ended
	Dec. 31, 2013
Monetary Production Payment [Abstract]	'
Schedule Of Monetary Production Payment Liability	'
		December 31,
		2013		2012
	Monetary production payment	$	166,667	$	—
	Less:  current portion		74,167		—
	Long-term monetary production payment	$	92,500	$	—

Other_Liabilities_Tables

Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Other Liabilities [Abstract]	'
Schedule Of Other Liabilities	'
		December 31,
		2013		2012
	Asset retirement obligations	$	121,534	$	139,821
	Long-term derivative liabilities		9,245		7,402
	Other		591		469
	Total Other Liabilities	$	131,370	$	147,692
Schedule Of Asset Retirement Obligations	'
		Year Ended
		December 31,
		2013		2012
	Carrying amount of asset retirement obligations, as of beginning of period	$	176,076	$	47,258
	Increase (decrease) due to revised estimates		-10,304		102,447
	Accretion expense (included in DD&A expense)		23,793		7,542
	Impact of foreign currency exchange rate changes		3,205		3,019
	Payment of asset retirement obligations		-27,690		-8,521
	Liabilities incurred and assumed		5,349		24,331
	Carrying amount of asset retirement obligations, as of end of year		170,429		176,076
	Less: current portion of asset retirement obligations		-48,895		-36,255
	Long-term asset retirement obligations	$	121,534	$	139,821

Equity_Tables

Equity (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Schedule Of Common And Preferred Stock Activity	'
		Year Ended December 31, 2013
		2013	2012	2011
	Common Stock:
	Outstanding at the beginning of the year	46,691	37,663	24,784
	Issuance of common stock	—	8,625	11,531
	Exercise of stock options	23	—	93
	Conversion of preferred stock	—	—	914
	Issuance of stock based compensation	267	403	341
	Outstanding at the end of the year	46,981	46,691	37,663
	Series B Preferred Stock:
	Outstanding at the end of the year	20	20	20
	Series C Convertible Preferred Stock:
	Outstanding at the beginning of the year	37	37	45
	Conversion to common stock	—	—	-8
	Outstanding at the end of the year	37	37	37
	Treasury Stock:
	Outstanding at the end of the year	-72	-72	-72

StockBased_Compensation_Arrang1

Stock-Based Compensation Arrangements (Tables)	12 Months Ended
	Dec. 31, 2013
Stock-Based Compensation Arrangements [Abstract]	'
Schedule Of Outstanding Stock Options	'
					Weighted			Weighted
			Number of		Average			Average
			Shares		Exercise			Contractual		Aggregate
			Underlying		Price per			Life in		Intrinsic
			Options		Share			Years		Value
	Balance outstanding January 1, 2013		188		$	6.72
	Exercised		-23			3.78
	Forfeited		-45			5.98
	Balance outstanding  - December 31, 2013		120		$	7.55		4.3		$	55
	Currently exercisable - December 31, 2013		120		$	7.55		4.3		$	55
Schedule Of Stock Options Outstanding By Exercise Price	'
			Options Outstanding							Options Exercisable
	Range of Exercise Prices		Number of Options Outstanding		Weighted Average Remaining Contractual Life		Weighted Average Exercise Price Per Share			Number Exercisable		Weighted Average Exercise Price Per Share
	Less than $5.00		37		5		$	3.78		37		$	3.78
	$5.00 - $8.00		—		—			—		—			—
	Greater than $8.00		83		4			9.23		83			9.23
	Total		120		4.3		$	7.55		120		$	7.55
Schedule Of Restricted Shares Granted	'
						Weighted
						Average Grant
						Date Fair
			Number of			Value per
			Shares			Share
	Balance outstanding - January 1, 2013			754		$	10.11
	Granted			562			5.23
	Vested			-393			9.90
	Forfeited			-295			6.98
	Balance outstanding - December 31, 2013			628		$	7.44
	Total grant date fair value of shares vesting during the period		$	3,892
Schedule Of General And Administrative Expenses	'
			Year Ended
			31-Dec-13
		2013			2012			2011
	G&A Expenses	$	3,607		$	4,641		$	2,988
	Capitalized G&A		1,236			1,634			1,051
	Total non-cash stock-based compensation	$	4,843		$	6,275		$	4,039
Schedule Of Performance-Based Share Awards	'
					Weighted
					Average Grant
					Date Fair
			Number of		Value per
			Shares		Share
	Balance outstanding - January 1, 2013		358		$	16.72
	Granted		562			7.41
	Forfeited		-213			11.07
	Balance outstanding - December 31, 2013		707		$	11.01

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Schedule Of Common Shares Potentially Issuable	'
		For the Year Ended December 31,
		2013	2012	2011
	Options, warrants and stock-based compensation	7,981	2,111	111
	Convertible debt	12,041	11,532	11,078
	Convertible preferred stock	4,229	4,229	4,229
	Common shares potentially issuable	24,251	17,872	15,418

Supplementary_Cash_Flow_Disclo

Supplementary Cash Flow Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Disclosures [Abstract]	'
Schedule Of Supplemental Cash Flow Information	'
		Year Ended December 31,
		2013		2012		2011
	Interest paid	$	94,941	$	66,365	$	31,928
	Income taxes paid	$	57,132	$	426	$	9,427

Financial_Instruments_Tables

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Financial Instruments [Abstract]	'
Financial Instruments Disclosure [Table Text Block]	'
		31-Dec-13				31-Dec-12
		Fair Value		Carrying Value		Fair Value		Carrying Value
	Liabilities:
	Debt	$	868,406	$	870,878	$	869,488	$	859,506
	Derivative instruments		9,245		9,245		7,402		7,402

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Measurements [Abstract]	'
Schedule Of Valuations Of Investments And Financial Instruments	'
		Quoted Market Prices				Significant Other			Significant
		in Active Markets -				Observable Inputs -			Unobservable Inputs -			Total
		Level 1				Level 2			Level 3			Fair Value
	As of December 31, 2013:
	Embedded derivatives		$	—			$	—		$	-9,245		$	-9,245
	Total derivative liabilities		$	—			$	—		$	-9,245		$	-9,245
	As of December 31, 2012:
	Embedded derivatives			—				—			-7,402			-7,402
	Total derivative liabilities		$	—			$	—		$	-7,402		$	-7,402
Schedule Of Reconciliation Of Fair Value Of Derivative Assets And Liabilities	'
		Year Ended
		December 31,
		2013			2012
	Balance at beginning of period	$	-7,402		$	-15,858
	Total gains or losses (realized/unrealized)
	Included in earnings		-1,843			8,456
	Balance at end of period	$	-9,245		$	-7,402
	Changes in unrealized gains (losses) relating to derivatives assets and liabilities
	still held at the end of the period	$	-1,843		$	8,665

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments [Abstract]	'
Schedule Of Fair Market Value Of Derivative Instruments Included On The Balance Sheet	'
		December 31,
		2013		2012
	Derivatives not designated as hedges:
	Embedded derivatives related to debt and equity instruments:
	Other liabilities - long-term	$	-9,245	$	-7,402
Schedule Of Effect Of Derivatives Not Designated As Hedges On Results Of Operations	'
		Year Ended December 31,
		2013		2012		2011
	Derivatives not designated as hedges:
	Oil and gas commodity derivatives:
	Unrealized gains (losses)	$	—	$	-3,524	$	-3,050
	Embedded derivatives related to debt and equity instruments:
	Unrealized gains (losses)	$	-1,843	$	8,665	$	11,428

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies [Abstract]	'
Schedule Of Future Minimum Rental Payments	'
	2014	$	1,723
	2015		1,743
	2016		1,516
	2017		255
	Thereafter		—

Segment_And_Geographic_Informa1

Segment And Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment And Geographic Information [Abstract]	'
Schedule Of Operations By Geographic Area	'
		2013				2012				2011
		Revenue		Long-lived Assets			Revenue	Long-lived Assets		Revenue		Long-lived Assets
	United States	$	8,368	$	113,888	$	11,877	$	123,977	$	18,337	$	139,236
	United Kingdom		329,296		1,247,248		207,181		1,189,870		41,754		650,943
	Other		—		3,475		—		2,264		—		1,287
	Total	$	337,664	$	1,364,611	$	219,058	$	1,316,111	$	60,091	$	791,466
	Total International	$	329,296	$	1,250,723	$	207,181	$	1,192,134	$	41,754	$	652,230

Quarterly_Financial_Data_Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]	'
Schedule Of Quarterly Financial Data	'
			First Quarter		Second Quarter		Third Quarter		Fourth Quarter
			2013 (1)
	Revenues		$	57,672	$	126,165	$	36,901	$	116,926
	Operating expenses			49,453		94,908		44,899		87,922
	Operating profit (loss)			8,219		31,257		-7,998		29,004
	Net loss to common stockholders			-14,502		-14,341		-40,341		-28,118
	Net loss  per common share - basic and diluted			-0.31		-0.3		-0.86		-0.6
			2012 (2)  (3)
	Revenues		$	15,166	$	23,003	$	83,275	$	97,615
	Operating expenses			33,867		41,359		64,174		59,857
	Operating profit (loss)			-18,701		-18,356		19,101		37,758
	Net loss to common stockholders			-35,718		-51,264		-34,158		-6,910
	Net loss  per common share - basic and diluted			-0.94		-1.31		-0.73		-0.15
	-1	Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.
	-2	Includes impairments of oil and gas properties of $15.7 million,  $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.
	-3	Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxes
		in prior periods that was not material to the current year operations.

Guarantor_Subsidiaries_Tables

Guarantor Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Schedule Of Condensed Financial Statements	'
	As of December 31, 2013
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
	Cash and cash equivalents	$	-	$	2,417	$	32,325	$	-	$	34,742
	Accounts receivable		-		1,832		63,339		-		65,171
	Current receivables due from affiliates		853,900		20,783		45,982		-920,665		-
	Prepaid expenses and other		-		594		59,724		-		60,318
	Current Assets		853,900		25,626		201,370		-920,665		160,231
	Property, plant and equipment, net		-		87,313		984,838		-		1,072,151
	Goodwill		-		-		259,238		-		259,238
	Long-term receivables due from affiliates		-		500,000		8		-500,008		-
	Investments in subsidiaries		57,662		219,066		-		-276,728		-
	Other assets		20,518		6,056		6,648		-		33,222
	Total Assets	$	932,080	$	838,061	$	1,452,102	$	-1,697,401	$	1,524,842
	Accounts payable	$	-	$	1,214	$	36,819	$	-	$	38,033
	Deferred revenue		-		-		20,965		-		20,965
	Monetary production payment, current portion		-		-		74,167		-		74,167
	Current liabilities due to affiliates		648		899,853		20,171		-920,672		-
	Accrued expenses and other		27,474		3,352		57,799		-		88,625
	Current Liabilities		28,122		904,419		209,921		-920,672		221,790
	Long-term debt		678,850		-		192,028		-		870,878
	Long-term liabilities due to affiliates		-		-		500,000		-500,000		-
	Deferred taxes		-		-		146,213		-		146,213
	Monetary production payment, long-term portion		-		-		92,500		-		92,500
	Other liabilities		3,535		602		127,234		-		131,370
	Total Liabilities		710,507		905,021		1,267,896		-1,420,672		1,462,751
	Series C convertible preferred stock		43,703		-		-		-		43,703
	Stockholders' equity		177,870		-66,960		184,206		-276,728		18,388
	Total Liabilities and Equity	$	932,080	$	838,061	$	1,452,102	$	-1,697,401	$	1,524,842
	As of December 31, 2012
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
	Cash and cash equivalents	$	-	$	27,800	$	31,385	$	-	$	59,185
	Accounts receivable		-		2,695		43,486		-		46,181
	Current receivables due from affiliates		950,210		36,725		71,964		-1,058,899		-
	Prepaid expenses and other		-		508		38,559		-		39,067
	Current Assets		950,210		67,728		185,394		-1,058,899		144,433
	Property, plant and equipment, net		-		92,692		910,749		-		1,003,441
	Goodwill		-		-		262,764		-		262,764
	Long-term receivables due from affiliates		-		599,000		-		-599,000		-
	Investments in subsidiaries		57,662		120,058		-		-177,720		-
	Other assets		25,200		6,085		18,621		-		49,906
	Total Assets	$	1,033,072	$	885,563	$	1,377,528	$	-1,835,619	$	1,460,544
	Accounts payable	$	-	$	2,622	$	57,531	$	-	$	60,153
	Current maturities of debt		-		-		15,713		-		15,713
	Deferred revenue		-		-		-		-		-
	Monetary production payment deposit		-		-		-		-		-
	Current liabilities due to affiliates		34,509		987,664		36,726		-1,058,899		-
	Accrued expenses and other		27,548		1,517		61,035		-		90,100
	Current Liabilities		62,057		991,803		171,005		-1,058,899		165,966
	Long-term debt		676,413		-		167,380		-		843,793
	Long-term liabilities due to affiliates		-		-		599,000		-599,000		-
	Deferred taxes		-		-		159,959		-		159,959
	Monetary production payment, long-term portion		-		-		-		-		-
	Other liabilities		3,033		561		144,098		-		147,692
	Total Liabilities		741,503		992,364		1,241,442		-1,657,899		1,317,410
	Series C convertible preferred stock		43,703		-		-		-		43,703
	Stockholders' equity		247,866		-106,801		136,086		-177,720		99,431
	Total Liabilities and Equity	$	1,033,072	$	885,563	$	1,377,528	$	-1,835,619	$	1,460,544
	For the Year Ended December 31, 2013
		Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
	Revenue	$	-	$	8,368	$	329,296	$	-	$	337,664
	Operating expenses		-		7,399		98,045		-		105,444
	DD&A expense		-		4,249		138,799		-		143,048
	Impairment of oil and gas properties		-		9,566		-		-		9,566
G&A expenses		2,502		7,764		8,858		-		19,124
Income (loss) from Operations		-2,502		-20,610		83,594		-		60,482
Derivatives:
Unrealized losses		-503		-		-1,340		-		-1,843
Interest expense		-81,400		2,988		-86,105		60,001		-104,516
Letter of credit fees		-		-		-33,425		-		-33,425
Other income (expense)		-27		57,463		-7,170		-60,001		-9,735
Income (loss) before taxes		-84,432		39,841		-44,446		-		-89,037
Income tax expense		-		-		6,442		-		6,442
Net income (loss)		-84,432		39,841		-50,888		-		-95,479
Preferred stock dividends		1,823		-		-		-		1,823
Net income (loss) to common shareholders	$	-86,255	$	39,841	$	-50,888	$	-	$	-97,302
For the Year Ended December 31, 2012
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
Revenue	$	-	$	11,877	$	207,181	$	-	$	219,058
Operating expenses		-		6,968		51,568		-		58,536
DD&A expense		-		8,603		57,961		-		66,564
Impairment of oil and gas properties		-		53,072		-		-		53,072
G&A expenses		2,629		9,887		8,569		-		21,085
Income (loss) from Operations		-2,629		-66,653		89,083		-		19,801
Derivatives:
Unrealized gains (losses)		-705		-		5,846		-		5,141
Interest expense		-54,241		-951		-67,673		38,743		-84,122
Letter of credit fees		-		-		-21,903		-		-21,903
Loss on early extinguishment of debt		-		-		-21,661		-		-21,661
Other income (expense)		-		33,796		-4,307		-38,743		-9,254
Loss before taxes		-57,575		-33,808		-20,615		-		-111,998
Income tax expense		-		-		21,225		-6,997		14,228
Net loss		-57,575		-33,808		-41,840		6,997		-126,226
Preferred stock dividends		1,823		-		-		-		1,823
Net loss to common shareholders	$	-59,398	$	-33,808	$	-41,840	$	6,997	$	-128,049
For the Year Ended December 31, 2011
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations		Consolidated
Revenue	$	-	$	18,337	$	41,754	$	-	$	60,091
Operating expenses		-		9,046		8,622		-		17,668
DD&A expense		-		11,490		14,988		-		26,478
Impairment of oil and gas properties		-		65,706		-		-		65,706
G&A expenses		2,198		10,789		4,866		-		17,853
Income (loss) from Operations		-2,198		-78,694		13,278		-		-67,614
Derivatives:
Unrealized gains (losses)		-2,642		-		11,020		-		8,378
Interest expense		-10,623		-3,964		-38,894		8,588		-44,893
Loss on early extinguishment of debt		-402		-		-		-		-402
Unrealized foreign currency gains (losses)		-		-	-	2,189	-	-	-	2,188
Other income (expense)		-211		-678		7,885		-8,588		-1,591
Loss before taxes		-16,076		-83,336		-4,522		-		-103,934
Income tax expense		-		3		27,058		-		27,061
Net loss		-16,076		-83,339		-31,580		-		-130,995
Preferred stock dividends		1,974		-		-		-		1,974
Net loss to common shareholders	$	-18,050	$	-83,339	$	-31,580	$	-	$	-132,969
For the Year Ended December 31, 2013
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-84,432	$	39,841	$	-50,888	$	—	$	-95,479
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		4,249		138,799		—		143,048
Impairment of oil and gas properties		—		9,566		—		—		9,566
Deferred tax benefit		—		—		-14,255		—		-14,255
Unrealized (gains) losses on derivatives		503		—		1,340		—		1,843
Amortization of non-cash compensation		622		—		—		2,984		3,606
Amortization of loan costs and discount		7,826		—		14,533		—		22,359
Non-cash interest expense		—		-12,958		20,040		—		7,082
Other		44		12,942		3,344		—		16,330
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		863		-19,854		—		-18,991
(Increase) decrease in other current assets		—		-14,252		15,576		—		1,324
Increase (decrease) in liabilities		—		-13,628		-24,395		19,038		-18,985
Net Cash Provided by (Used in)
Operating Activities		-75,437		26,623		84,240		22,022		57,448
Cash Flows From Investing Activities:
Capital expenditures		—		-15,111		-211,881		1,237		-225,755
Acquisitions, net of cash acquired		—		65		-2,852		—		-2,787
Proceeds from sales, net of cash		—		6,712		62		—		6,774
Net Cash Used in Investing Activities		—		-8,335		-214,670		1,237		-221,768
Cash Flows From Financing Activities:
Repayments of borrowings		—		—		—		—		—
Borrowings under debt agreements, net
of debt discount		—		—		—		—		—
Exercise of stock options		—		—		—		—		—
Borrowings from affiliates		—		—		—		—		—
Proceeds from issuance of MPP		—		—		175,000		—		175,000
Proceeds from issuance of common stock		—		—		—		—		—
Repayments of MPP		—		—		-8,333				-8,333
Payments for early extinguishment of debt		—		—		—		—		—
Financing costs paid		-700		-500		-35,296		11,286		-25,210
Intercompany cash management		77,874		-43,329		—		-34,545		—
Other financing		-1,737		157		—		—		-1,580
Net Cash Provided by (Used in)
Financing Activities		75,437		-43,672		131,371		-23,259		139,877
Net Change in Cash and Cash Equivalents		—		-25,383		940		—		-24,443
Cash and Cash Equivalents, Beginning
of Period		—		27,800		31,385		—		59,185
Cash and Cash Equivalents, End of Period	$	—	$	2,417	$	32,325	$	—	$	34,742
For the Year Ended December 31, 2012 (2)
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-57,575	$	-33,808	$	-41,840	$	6,997	$	-126,226
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		8,603		57,961		—		66,564
Impairment of oil and gas properties		—		53,072		—		—		53,072
Deferred tax benefit		—		—		-10,597		-6,997		-17,594
Unrealized (gains) losses on derivatives		705		—		-5,846		—		-5,141
Amortization of non-cash compensation		854		—		—		3,547		4,401
Amortization of loan costs and discount		6,908		5		7,266		—		14,179
Non-cash interest expense		445		—		8,239		—		8,684
Loss on early extinguishment of debt		—		—		21,661		—		21,661
Other		283		173		14,909		—		15,365
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		1,495		-25,814		—		-24,319
(Increase) decrease in other current assets		—		-9,223		8,631		—		-592
Increase (decrease) in liabilities		—		88,635		-21,617		-38,459		28,559
Net Cash Provided by (Used in)
Operating Activities		-48,380		108,952		12,953		-34,912		38,613
Cash Flows From Investing Activities:
Capital expenditures		—		-39,794		-207,131		—		-246,925
Acquisitions, net of cash acquired		—		-2,372		-236,482		—		-238,854
Proceeds from sales, net of cash		—		—		1,407		—		1,407
Issuance of note receivable to affiliate		—		-500,000		—		500,000		—
Increase in restricted cash		—		-50		-128		—		-178
Net Cash Used in Investing Activities		—		-542,216		-442,334		500,000		-484,550
Cash Flows From Financing Activities:
Repayments of borrowings		-32,457		—		-242,172		—		-274,629
Borrowings under debt agreements, net
of debt discount		538,860		—		115,163		—		654,023
Borrowings from affiliates		—		—		500,000		-500,000		—
Proceeds from issuance of MPP		—		—		—		—		—
Proceeds from issuance of common stock		60,805		—		—		—		60,805
Dividends paid		—		—		—		—		—
Payments for early extinguishment of debt		—		—		-7,248		—		-7,248
Financing costs paid		-24,141		—		-8,063		—		-32,204
Intercompany cash management		-493,026		458,114		—		34,912		—
Other financing		-1,661		—		—		—		-1,661
Net Cash Provided by (Used in)
Financing Activities		48,380		458,114		357,680		-465,088		399,086
Net Change in Cash and Cash Equivalents		—		24,849		-71,700		—		-46,851
Cash and Cash Equivalents, Beginning
of Period		—		2,951		103,085		—		106,036
Cash and Cash Equivalents, End of Period	$	—	$	27,800	$	31,385	$	—	$	59,185
For the Year Ended December 31, 2011 (2)
	Endeavour International Corporation		Combined Guarantor Subsidiaries		Combined Non-Guarantor Subsidiaries		Eliminations (1)		Consolidated
Cash Flows from Operating Activities:
Net loss	$	-16,076	$	-83,339	$	-31,580	$	—	$	-130,995
Adjustments to reconcile net loss to
net cash provided by (used in) operations
DD&A expense		—		11,490		14,988		—		26,478
Impairment of oil and gas properties		—		65,706		—		—		65,706
Deferred tax benefit		—		—		21,116		—		21,116
Unrealized (gains) losses on derivatives		2,642		—		-11,020		—		-8,378
Amortization of non-cash compensation		624		—		—		3,073		3,697
Amortization of loan costs and discount		1,049		-403		11,588		—		12,234
Non-cash interest expense		880		—		11,931		—		12,811
Loss on early extinguishment of debt		402		—		—		—		402
Other		-82		105		1,495		—		1,518
Changes in operating assets and liabilities:
(Increase) decrease in receivables		—		-1,597		1,066		—		-531
(Increase) decrease in other current assets		34		2,872		-16,234		—		-13,328
Increase (decrease) in liabilities		—		-39,135		11,732		-2,670		-30,073
Net Cash Provided by (Used in)
Operating Activities		-10,527		-44,301		15,082		403		-39,343
Cash Flows From Investing Activities:
Capital expenditures		—		-80,279		-84,783		—		-165,062
Acquisitions, net of cash acquired		—		-8,027		-25,048		—		-33,075
Increase in restricted cash		—		—		31,726		—		31,726
Net Cash Used in Investing Activities		—		-88,306		-78,105		—		-166,411
Cash Flows From Financing Activities:
Repayments of borrowings		-101,250		—		-1,975		—		-103,225
Borrowings under debt agreements, net
of debt discount		135,000		—		75,000		—		210,000
Proceeds from issuance of common stock		118,444		—		—		—		118,444
Dividends paid		—		—		—		—		—
Financing costs paid		-5,926		—		-5,475		—		-11,401
Intercompany cash management		-134,457		134,860		—		-403		—
Other financing		-1,284		-11		—		—		-1,295
Net Cash Provided by (Used in)
Financing Activities		10,527		134,849		67,550		-403		212,523
Net Change in Cash and Cash Equivalents		—		2,242		4,527		—		6,769
Cash and Cash Equivalents, Beginning
of Period		—		709		98,558		—		99,267
Cash and Cash Equivalents, End of Period	$	—	$	2,951	$	103,085	$	—	$	106,036
	-1		The $7.0 million adjustment reflects the correction of an immaterial error in deferred income taxes that was corrected to beginning stockholder’s equity as of January 1, 2010 in the separate financials of the non-guarantor subsidiaries but reflected in the current year statement of operations for Endeavour.
Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.”  There was no impact to Consolidated balances.

Supplemental_Oil_And_Gas_Discl1

Supplemental Oil And Gas Disclosures (Tables)	12 Months Ended
	Dec. 31, 2013
Supplemental Oil And Gas Disclosures [Abstract]	'
Capitalized Costs Related To Oil And Gas Producing Activities	'
	Capitalized Costs Relating to Oil and Gas Producing Activities
			United Kingdom			United States		Total
	December 31, 2013:
	Proved		$	1,043,927		$	40,741	$	1,084,668
	Unproved			295,083			73,578		368,661
	Total capitalized costs			1,339,010			114,319		1,453,329
	Accumulated depreciation, depletion and amortization			-355,366			-27,429		-382,795
	Net capitalized costs		$	983,644		$	86,890	$	1,070,534
	December 31, 2012:
	Proved		$	876,536		$	39,265	$	915,801
	Unproved			273,298			76,135		349,433
	Total capitalized costs			1,149,834			115,400		1,265,234
	Accumulated depreciation, depletion and amortization			-241,338			-24,269		-265,607
	Net capitalized costs		$	908,496		$	91,131	$	999,627
Costs Incurred In Oil And Gas Property Acquisition, Exploration And Development Activities	'
	Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities
				United Kingdom			United States		Total
	Year Ended December 31, 2013:
	Acquisition costs:
	Proved		$	—		$	—	$	—
	Unproved			2,323			463		2,786
	Exploration costs			39,202			11,644		50,846
	Development costs			146,685			3,088		149,773
	Total costs incurred		$	188,210		$	15,195	$	203,405
	Year Ended December 31, 2012:
	Acquisition costs:
	Proved		$	143,004		$	1,176	$	144,180
	Unproved			46,878			1,156		48,034
	Exploration costs			46,730			15,397		62,127
	Development costs			302,038			8,099		310,137
	Total costs incurred		$	538,650		$	25,828	$	564,478
	Year Ended December 31, 2011:
	Acquisition costs:
	Proved		$	2,595		$	—	$	2,595
	Unproved			46,107			2,840		48,947
	Exploration costs			51,820			75,880		127,700
	Development costs			79,898			10,560		90,458
	Total costs incurred		$	180,420		$	89,280	$	269,700
Results Of Operatings For Oil And Gas Producing Activities	'
	Results of Operations for Oil and Gas Producing Activities
			United Kingdom	United States		Total
	Year Ended December 31, 2013:
	Revenues	$	329,296	$	8,368	$	337,664
	Production expenses		98,045		7,399		105,444
	DD&A		137,739		3,242		140,981
	Impairment of oil and gas properties		—		9,566		9,566
	Income tax expense (benefit)		57,977		-4,144		53,833
	Results of activities	$	35,535	$	-7,695	$	27,840
	Year Ended December 31, 2012:
	Revenues	$	207,181	$	11,877	$	219,058
	Production expenses		51,568		6,968		58,536
	DD&A		56,813		7,574		64,387
	Impairment of oil and gas properties		—		53,072		53,072
	Income tax expense (benefit)		61,256		-19,508		41,748
	Results of activities	$	37,544	$	-36,229	$	1,315
	Year Ended December 31, 2011:
	Revenues	$	41,754	$	18,337	$	60,091
	Production expenses		8,622		9,046		17,668
	DD&A		14,312		10,713		25,025
	Impairment of oil and gas properties		—		65,706		65,706
	Income tax expense (benefit)		11,104		-23,495		-12,391
	Results of activities	$	7,716	$	-43,633	$	-35,917
Schedule Of Oil And Gas Reserves	'
			United Kingdom		United States		Total
	Proved Oil Reserves (MBbls):
	Proved reserves at January 1, 2011		3,664		59		3,723
	Production		-373		-7		-380
	Extensions and discoveries		303		—		303
	Revisions of previous estimates		466		-11		455
	Proved reserves at December 31, 2011		4,060		41		4,101
	Production		-1,994		-3		-1,997
	Purchases of reserves		11,071		—		11,071
	Sales of reserves in place		—		-19		-19
	Extensions and discoveries		1,992		—		1,992
	Revisions of previous estimates		-1,396		-13		-1,409
	Proved reserves at December 31, 2012		13,733		6		13,739
	Production		-3,017		-1		-3,018
	Purchases of reserves		—		—		—
	Sales of reserves in place		—		—		—
	Extensions and discoveries		—		—		—
	Revisions of previous estimates		1,624		-3		1,621
	Proved reserves at December 31, 2013		12,340		2		12,342
	Proved Developed Oil Reserves (MBbls):
	At December 31, 2011		1,270		41		1,311
	At December 31, 2012		5,261		6		5,267
	At December 31, 2013		5,659		2		5,661
			United Kingdom		United States		Total
	Proved Gas Reserves (MMcf):
	Proved reserves at January 1, 2011		56,177		31,777		87,954
	Production		-94		-5,076		-5,170
	Purchases of reserves		90		—		90
	Extensions and discoveries		—		46,100		46,100
	Revisions of previous estimates		-5,450		-11,823		-17,273
	Proved reserves at December 31, 2011		50,723		60,978		111,701
	Production		-91		-5,206		-5,297
	Purchases of reserves		1,409		998		2,407
	Sales of reserves in place		—		-5,213		-5,213
	Extensions and discoveries		473		—		473
	Revisions of previous estimates		4,387		-36,867		-32,480
	Proved reserves at December 31, 2012		56,901		14,690		71,591
	Production		-1,194		-2,636		-3,830
	Purchases of reserves		—		—		—
	Sales of reserves in place		—		-4,200		-4,200
	Extensions and discoveries		—		—		—
	Revisions of previous estimates		-309		3,921		3,612
	Proved reserves at December 31, 2013		55,398		11,775		67,173
	Proved Developed Gas Reserves (MMcf):
	At December 31, 2011		795		22,704		23,499
	At December 31, 2012		3,147		14,690		17,837
	At December 31, 2013		18,384		9,792		28,176
			United Kingdom		United States		Total
	Proved Reserves (MBOE):
	Proved reserves at January 1, 2011		13,027		5,355		18,382
	Production		-389		-853		-1,242
	Extensions and discoveries		—		7,683		7,683
	Purchase of proved reserves, in place		318		—		318
	Revisions of previous estimates		-442		-1,981		-2,423
	Proved reserves at December 31, 2011		12,514		10,204		22,718
	Production		-2,009		-871		-2,880
	Extensions and discoveries		2,071		—		2,071
	Purchase of proved reserves, in place		11,306		166		11,472
	Sale of reserves		—		-888		-888
	Revisions of previous estimates		-665		-6,157		-6,822
	Proved reserves at December 31, 2012		23,217		2,454		25,671
	Production		-3,216		-440		-3,656
	Extensions and discoveries		—		—		—
Purchase of proved reserves, in place		—		—		—
Sale of reserves		—		-700		-700
Revisions of previous estimates		1,572		651		2,223
Proved reserves at December 31, 2013		21,573		1,965		23,538
Proved Developed Reserves (MBOE):
At December 31, 2011		1,402		3,825		5,227
At December 31, 2012		5,785		2,454		8,239
At December 31, 2013		8,723		1,634		10,357
Prices Used To Determine Estimated Future Cash Inflows	'
			December 31,
			2013				2012
			Oil		Gas		Oil	Gas
			($/Barrel)		($/Mcf)		($/Barrel)	($/Mcf)
	United Kingdom		104.45		10.38		111.13	9.34
	United States		97.71		2.94		94.71	2.75

General_Details

General (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Mar. 01, 2014	Mar. 01, 2014
			Subsequent Event [Member]	Subsequent Event [Member]
				6.5% Convertible Notes [Member]
Debt Instrument [Line Items]	'	'	'	'
Outstanding indebtedness	$882,600,000	$874,192,000	'	'
Value of common stock issued	'	'	12,500,000	'
Debt principal amount	'	'	'	$17,500,000
Interest rate	'	'	'	6.50%

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Accounting Policies [Line Items]	'
Discount percentage	10.00%
Additional shares available for issuance	1.8
Minimum [Member]	'
Accounting Policies [Line Items]	'
Property and equipment, useful life	'2 years
Minimum [Member] | Shell U.K. Limited [Member] | Sales Revenue [Member]	'
Accounting Policies [Line Items]	'
Percentage of sales	10.00%
Maximum [Member]	'
Accounting Policies [Line Items]	'
Property and equipment, useful life	'5 years

Business_Combinations_Narrativ

Business Combinations (Narrative) (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

7 Months Ended

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

31-May-12

31-May-12

Dec. 31, 2012

Dec. 31, 2013

Dec. 14, 2012

Alba Field [Member]

Alba Field [Member]

Alba Field [Member]

Alba Field [Member]

MacCulloch Field [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisition date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31-May-12

'

Cash paid

'

'

'

'

'

'

'

'

'

'

'

$229,577,000

'

'

'

'

Interest percentage in entity

'

'

'

'

'

'

'

'

'

'

'

23.43%

23.43%

'

'

'

Interest acquired, percentage

'

'

'

'

'

'

'

'

'

'

'

'

25.68%

'

'

'

Proceeds from Notes Payable

'

'

'

'

'

'

'

'

'

'

'

205,000,000

'

'

'

'

Amount outstanding

'

'

'

'

'

'

'

'

'

'

'

24,000,000

24,000,000

'

'

'

Total Deposit With Sellers Of Property

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

Acquisition Field Revenue

116,926,000

[1]

36,901,000

[1]

126,165,000

[1]

57,672,000

[1]

97,615,000

[2],[3]

83,275,000

[2],[3]

23,003,000

[2],[3]

15,166,000

[2],[3]

337,664,000

219,058,000

60,091,000

'

'

119,700,000

'

'

Acquisition income from operations

$29,004,000

[1]

($7,998,000)

[1]

$31,257,000

[1]

$8,219,000

[1]

$37,758,000

[2],[3]

$19,101,000

[2],[3]

($18,356,000)

[2],[3]

($18,701,000)

[2],[3]

$60,482,000

$19,801,000

($67,614,000)

'

'

$13,700,000

'

'

[1]

Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.

[2]

Includes impairments of oil and gas properties of $15.7 million, $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.

[3]

Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxesin prior periods that was not material to the current year operations.

Business_Combinations_Schedule

Business Combinations (Schedule Of Purchase Price Allocation) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	31-May-12
In Thousands, unless otherwise specified				Alba Field [Member]
Business Acquisition [Line Items]	'	'	'	'
Purchase price	'	'	'	$255,400
Purchase Price adjustments for estimated after tax cash flows from the acquired asset and interest costs from effective date of January 1, 2011 to closing	'	'	'	-25,823
Total purchase price	'	'	'	229,577
Property and equipment	'	'	'	191,507
Additions related to goodwill	259,238	262,764	211,886	47,353
Current assets	'	'	'	24,632
Current liabilities	'	'	'	-12,815
Deferred tax liability	'	'	'	-6,999
Other long-term liabilities	'	'	'	-14,101
Total purchase price	'	'	'	$229,577

Prepaid_Expenses_And_Other_Cur1

Prepaid Expenses And Other Current Assets (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Prepaid Expenses And Other Current Assets [Abstract]	'	'
Prepaid well and drilling costs	$24	$2,843
Prepaid insurance	3,707	3,330
Inventory	5,117	5,127
Deferred tax asset	26,583	26,161
Deferred financing costs - current portion	22,134	'
Other	2,753	1,606
Total prepaid expenses and other current assets	$60,318	$39,067

Property_And_Equipment_Narrati

Property And Equipment (Narrative) (Details) (USD $)

3 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Sep. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Nov. 08, 2013

Dec. 31, 2013

31-May-12

Dec. 31, 2013

31-May-12

Dec. 31, 2013

Haynesville Acreage [Member]

Marcellus Acreage [Member]

Samson Exploration LLC [Member]

Samson Exploration LLC [Member]

Alba Field [Member]

Alba Field [Member]

Alba Field [Member]

Alba Field [Member]

Oil And Gas Properties And Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Directly related employee costs capitalized

'

'

'

'

'

'

$12,400,000

$17,900,000

$13,300,000

'

'

'

'

'

'

'

'

Exploration and development related capitalized costs

'

'

'

'

'

'

24,000,000

26,900,000

14,700,000

'

'

'

'

'

'

'

'

Impairment of oil and gas properties

6,000,000

3,500,000

6,000,000

11,400,000

20,000,000

15,700,000

9,566,000

53,072,000

[1]

65,706,000

[1]

'

'

'

'

'

'

'

'

Acquisition date

'

'

'

'

'

'

'

'

'

'

26-Oct-12

'

8-Nov-13

'

31-May-12

'

31-May-12

Additional working interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

23.43%

'

Cash paid

'

'

'

'

'

'

'

'

'

'

'

'

'

$229,577,000

'

'

'

Ownership percentage of producing acreage

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

25.68%

'

Percentage of assets sold

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

[1]

Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Property_And_Equipment_Schedul

Property And Equipment (Schedule Of Property And Equipment) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	$1,453,329	$1,265,234
Computers, furniture and fixtures	8,734	8,863
Total property and equipment	1,462,063	1,274,097
Accumulated depreciation, depletion and amortization	-389,912	-270,656
Net property and equipment	1,072,151	1,003,441
Subject To Amortization [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	1,084,669	915,801
Not Subject To Amortization [Member] | Incurred in 2013 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	52,748	'
Not Subject To Amortization [Member] | Incurred in 2012 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	138,641	141,837
Not Subject To Amortization [Member] | Incurred in 2011 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	99,740	107,510
Not Subject To Amortization [Member] | Incurred prior to 2011 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Oil and gas properties under the full cost method	$77,531	$100,086

Property_And_Equipment_Schedul1

Property And Equipment (Schedule Of Properties Not Subject To Amortization) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Acquisition costs	$133,197	'
Exploration costs	202,562	'
Capitalized interest	32,901	'
Total oil and gas properties not subject to amortization	368,660	349,433
Incurred in 2013 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Acquisition costs	384	'
Exploration costs	35,584	'
Capitalized interest	16,780	'
Total oil and gas properties not subject to amortization	52,748	'
Incurred in 2012 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Acquisition costs	48,409	'
Exploration costs	77,200	'
Capitalized interest	13,032	'
Total oil and gas properties not subject to amortization	138,641	'
Incurred in 2011 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Acquisition costs	48,995	'
Exploration costs	47,656	'
Capitalized interest	3,089	'
Total oil and gas properties not subject to amortization	99,740	'
Incurred prior to 2011 [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Acquisition costs	35,409	'
Exploration costs	42,122	'
Total oil and gas properties not subject to amortization	$77,531	'

Goodwill_Details

Goodwill (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Abstract]	'	'
Goodwill, Beginning Balance	$262,764	$211,886
Purchase price adjustment	-3,526	50,878
Goodwill, Ending Balance	$259,238	$262,764

Other_Assets_Narrative_Details

Other Assets (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Loss Contingencies [Line Items]	'	'
Deposits related to SM Energy litigation	$6,000	'
SM Energy Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Deposits related to SM Energy litigation	$6,000	$6,000

Other_Assets_Schedule_Of_Other

Other Assets (Schedule Of Other Long-Term Assets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Loss Contingencies [Line Items]	'	'
Deposits related to SM Energy litigation	$6,000	'
Total other assets	33,222	49,906
SM Energy Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Debt issuance costs	20,856	30,599
Deferred issuance costs related to reimbursement agreements	'	11,290
Deposits related to SM Energy litigation	6,000	6,000
Other	6,366	2,017
Total other assets	$33,222	$49,906

Accrued_Expenses_And_Other_Cur2

Accrued Expenses And Other Current Liabilities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accrued Expenses And Other Current Liabilities [Abstract]	'	'
Foreign taxes payable	$2,875	$18,989
Accrued interest	29,512	25,932
Preferred dividends	1,774	1,617
Accrued compensation	3,210	1,882
Current portion of asset retirement obligation	48,895	36,255
Other	2,359	5,425
Total accrued expenses and other liabilities	$88,625	$90,100

Deferred_Revenue_Details

Deferred Revenue (Details) (United Kingdom North Sea [Member], USD $)	Sep. 30, 2013	Feb. 28, 2013
In Millions, unless otherwise specified	bbl	bbl
United Kingdom North Sea [Member]	'	'
Oil and Gas Delivery Commitments and Contracts [Line Items]	'	'
Deferred revenue	$22.50	$22.50
Number of barrels of oil to be delivered	200,000	200,000

Debt_Obligations_Senior_Notes_

Debt Obligations (Senior Notes Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Oct. 15, 2012	Oct. 15, 2012	Dec. 31, 2013	Dec. 31, 2012	Feb. 23, 2012	Feb. 23, 2012	Dec. 31, 2013	Feb. 23, 2012
			Senior Notes [Member]	First Priority Notes [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]	Senior Notes,12% Fixed Rate, Due 2018 [Member]
				Senior Notes [Member]			Senior Notes [Member]	First Priority Notes [Member]	First Priority Notes [Member]	Second Priority Notes [Member]
								Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'
Issuance date	'	'	'	'	'	'	'	'	23-Feb-12	'
Debt principal amount	'	'	'	$54,000,000	'	'	'	$350,000,000	'	$150,000,000
Interest rate	'	'	'	'	12.00%	'	'	12.00%	'	12.00%
Percentage of par	'	'	'	109.00%	'	'	'	96.00%	'	96.00%
Outstanding indebtedness	882,600,000	874,192,000	'	'	554,000,000	554,000,000	'	'	'	'
Yield percentage	'	'	'	'	'	'	'	12.98%	'	12.95%
Discount	11,722,000	14,686,000	'	'	'	'	20,000,000	'	'	'
Other financing costs	'	'	'	'	'	'	21,000,000	'	'	'
Proceeds from issuance of debt	'	'	'	57,900,000	'	'	'	'	'	'
Outstanding debt retired	'	'	$25,000,000	'	'	'	'	'	'	'

Debt_Obligations_Revolving_Cre

Debt Obligations (Revolving Credit Facility Narrative) (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2013	Apr. 12, 2012
In Millions, unless otherwise specified		Cyan Partners Limited Partnership [Member]	Cyan Partners Limited Partnership [Member]
		Revolving Credit Facility [Member]	Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]	'	'	'
Private placement offering amount	$125	'	$100
Amount outstanding	'	$115	$40

Debt_Obligations_55_Convertibl

Debt Obligations (5.5% Convertible Senior Notes Narrative) (Details) (Convertible Senior Notes, 5.5% Fixed Rate, Due 2016 [Member], USD $)	12 Months Ended
	Dec. 31, 2013
Debt Instrument [Line Items]	'
Interest rate	5.50%
Convertible Debt [Member]	'
Debt Instrument [Line Items]	'
Debt principal amount	$135,000,000
Interest rate	5.50%
Conversion rate	18.51
Conversion price	$18.51

Debt_Obligations_115_Convertib

Debt Obligations (11.5% Convertible Bonds) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]	'	'		'
Unrealized gains (losses)	($1,843,000)	$5,141,000	[1]	$8,378,000	[1]
11.5% Fixed Rate [Member] | Convertible Debt [Member]	'	'		'
Debt Instrument [Line Items]	'	'		'
Interest rate	11.50%	'		'
Proceeds from issuance of debt	40,000,000	'		'
Conversion price	$16.52	'		'
Conversion rate	16.39	'		'
Debt maturity date	24-Jan-16	'		'
Latest conversion date	24-Jan-16	'		'
Fair value of derivative	5,700,000	'		'
Unrealized gains (losses)	$1,300,000	'		'
7.5% Fixed Rate [Member]	'	'		'
Debt Instrument [Line Items]	'	'		'
Interest rate	7.50%	'		'
7.5% Fixed Rate [Member] | Convertible Debt [Member]	'	'		'
Debt Instrument [Line Items]	'	'		'
Interest rate	7.50%	'		'
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Debt_Obligations_Fair_Value_Na

Debt Obligations (Fair Value Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Obligations [Abstract]	'	'
Fair value of debt obligations outstanding	$868,406	$869,488

Debt_Obligations_Schedule_Of_D

Debt Obligations (Schedule Of Debt) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term debt, gross	$882,600	$874,192
Less: debt discount, net of premium	-11,722	-14,686
Less: current maturities	'	-15,713
Long-term debt	870,878	843,793
Senior Notes,12% Fixed Rate, Due 2018 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt, gross	554,000	554,000
Interest rate	12.00%	'
Convertible Senior Notes, 5.5% Fixed Rate, Due 2016 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt, gross	135,000	135,000
Interest rate	5.50%	'
Revolving Credit Facility, 13% Fixed Rate, Due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt, gross	115,163	115,163
Interest rate	13.00%	'
Convertible bonds, 11.5% until March 31, 2014 and 7.5% thereafter, due 2016 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt, gross	$78,437	$70,029
Interest rate	11.50%	'
7.5% Fixed Rate [Member]	'	'
Debt Instrument [Line Items]	'	'
Interest rate	7.50%	'

Debt_Obligations_Schedule_Of_D1

Debt Obligations (Schedule Of Debt Maturities) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Obligations [Abstract]	'
2014	$115,163
2015	'
2016	213,437
2017	'
2018	554,000
Thereafter	'

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Loss Carryforwards [Line Items]	'	'	'
U.S. statutory rate	35.00%	'	'
Loss before taxes	($89,037,000)	($111,998,000)	($103,934,000)
Valuation allowance for deferred tax assets	103,171,000	84,691,000	'
Unrecognized tax benefit	6,820,000	6,820,000	'
Incurred income tax interest or penalty expense	0	'	'
United States [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Loss before taxes	-44,591,000	-91,383,000	-99,409,000
Increase (decrease) in valuation allowance	18,300,000	'	'
United States [Member] | Net Revisions [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Increase (decrease) in valuation allowance	2,900,000	'	'
United States [Member] | Net Operating Loss [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Increase (decrease) in valuation allowance	15,400,000	29,100,000	24,600,000
United States [Member] | Net Operating Loss In Other Jurisdictions [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Increase (decrease) in valuation allowance	$200,000	($3,000,000)	($3,900,000)

Income_Taxes_Schedule_Of_Compo

Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Operating Loss Carryforwards [Line Items]	'	'		'
Net income (loss) before taxes	($89,037)	($111,998)		($103,934)
PRT tax current expense	20,667	31,796		5,926
PRT tax deferred benefit	-13,978	-14,823		-373
PRT tax expense	6,689	16,973		5,553
Corporate current expense	30	26		19
Corporate deferred benefit	-277	-11,358		-3,935
Deferred tax expense related to U.K. tax rate change	'	8,587		25,424
Corporate tax expense (benefit)	-247	-2,745		21,508
Total Income Tax Expense (Benefit)	6,442	14,228		27,061
Net Loss	-95,479	-126,226	[1]	-130,995	[1]
United Kingdom [Member]	'	'		'
Operating Loss Carryforwards [Line Items]	'	'		'
Net income (loss) before taxes	-35,273	-22,959		-9,806
PRT tax current expense	20,667	31,796		5,926
PRT tax deferred benefit	-13,978	-14,823		-373
PRT tax expense	6,689	16,973		5,553
Corporate deferred benefit	-277	-11,358		-3,935
Deferred tax expense related to U.K. tax rate change	'	8,587		25,424
Corporate tax expense (benefit)	-277	-2,771		21,489
Total Income Tax Expense (Benefit)	6,412	14,202		27,042
Net Loss	-41,685	-37,161		-36,848
United States [Member]	'	'		'
Operating Loss Carryforwards [Line Items]	'	'		'
Net income (loss) before taxes	-44,591	-91,383		-99,409
Corporate current expense	'	'		4
Corporate tax expense (benefit)	'	'		4
Total Income Tax Expense (Benefit)	'	'		4
Net Loss	-44,591	-91,383		-99,413
Other Countires [Member]	'	'		'
Operating Loss Carryforwards [Line Items]	'	'		'
Net income (loss) before taxes	-9,173	2,344		5,281
Corporate current expense	30	26		15
Corporate tax expense (benefit)	30	26		15
Total Income Tax Expense (Benefit)	30	26		15
Net Loss	($9,203)	$2,318		$5,266
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Income_Taxes_Schedule_Of_Effec

Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Abstract]	'	'	'
Federal income tax benefit at statutory rate	($31,163)	($39,199)	($36,378)
Taxation of foreign operations	21,998	5,859	3,254
Effect of out-of-period adjustment	'	6,997	'
Change in valuation allowance - U.S.	15,343	30,329	24,604
U.K. tax increase from tax law and rate change	'	8,587	25,424
Deemed foreign dividend of wholly owned subsidiaries	'	'	8,572
Disallowed executive compensation	247	1,655	1,585
Other	17	'	'
Total Income Tax Expense (Benefit)	$6,442	$14,228	$27,061
Effective Income Tax Rate	-7.00%	-13.00%	-26.00%

Income_Taxes_Schedule_of_Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred tax asset:	'	'
Deferred compensation	$2,401	$2,268
Asset retirement obligation	84,941	87,787
Net operating loss and capital loss carryforward	423,374	334,121
Unrealized loss on embedded derivative instruments	1,265	1,084
Property, plant and equipment	14,086	19,596
Inventory / other	2,185	8,089
Total deferred tax assets	528,252	452,945
Less valuation allowance	-103,171	-84,691
Total deferred tax assets after valuation allowance	425,081	368,254
Deferred tax liabilities:	'	'
Property, plant and equipment	-526,274	-478,719
Petroleum revenue tax, net of tax benefit	-17,967	-22,703
Debt discount	-471	-630
Total deferred tax liabilities	-544,712	-502,052
Net deferred tax liability	($119,631)	($133,798)

Income_Taxes_Schedule_Of_Tax_A

Income Taxes (Schedule Of Tax Attributes Available To Reduce Future Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
United Kingdom [Member] | Corporate Tax [Member] | Net Operating Loss Carryforward [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Carry-forward Amount	638,466	500,789
United Kingdom [Member] | Supplemental Corporate Tax [Member] | Net Operating Loss Carryforward [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Carry-forward Amount	455,318	378,602
United States [Member] | Corporate Tax [Member] | Net Operating Loss Carryforward [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Carry-forward Amount	232,745	177,206
United States [Member] | Corporate Tax [Member] | Net Operating Loss Carryforward [Member] | Minimum [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Years of Expiration	'2023	'2023
United States [Member] | Corporate Tax [Member] | Net Operating Loss Carryforward [Member] | Maximum [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Years of Expiration	'2033	'2032
United States [Member] | State Income Tax [Member] | Net Operating Loss Carryforward [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Carry-forward Amount	83,613	'
United States [Member] | State Income Tax [Member] | Net Operating Loss Carryforward [Member] | Minimum [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Years of Expiration	'2014	'
United States [Member] | State Income Tax [Member] | Net Operating Loss Carryforward [Member] | Maximum [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Years of Expiration	'2033	'
United States [Member] | Capital Gains Tax [Member] | Capital Loss Carryforward [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Years of Expiration	'2015	'2015
Carry-forward Amount	1,848	1,848

Income_Taxes_Schedule_Of_Chang

Income Taxes (Schedule Of Change In Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013
Income Taxes [Abstract]	'	'
Balance at the beginning of the year	'	$6,820
Increase in unrecognized tax benefits from current period tax position	6,820	'
Balance at the end of the year	$6,820	$6,820

Income_Taxes_Schedule_Of_Tax_Y

Income Taxes (Schedule Of Tax Years Subject To Examination) (Details)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | United Kingdom [Member]	'
Income Tax Examination [Line Items]	'
Remaining years subject to examination	'2012
Minimum [Member] | All Others [Member]	'
Income Tax Examination [Line Items]	'
Remaining years subject to examination	'2010
Maximum [Member] | United Kingdom [Member]	'
Income Tax Examination [Line Items]	'
Remaining years subject to examination	'2013
Maximum [Member] | All Others [Member]	'
Income Tax Examination [Line Items]	'
Remaining years subject to examination	'2013

Monetary_Production_Payment_Na

Monetary Production Payment (Narrative) (Details) (USD $)

12 Months Ended

1 Months Ended

3 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2013

Aug. 31, 2013

31-May-13

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Jan. 31, 2014

Mar. 01, 2014

Apr. 30, 2015

Jan. 31, 2015

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Alba And Bacchus Fields [Member]

Alba And Bacchus Fields [Member]

Rochelle Field [Member]

Warrants Expiring On April 30, 2018 [Member]

Warrants Expiring On April 30, 2018 [Member]

Warrants Expiring On May 21, 2018 [Member]

Warrants Expiring On May 21, 2018 [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Scenario, Forecast [Member]

Scenario, Forecast [Member]

Scenario, Forecast [Member]

Minimum [Member]

Maximum [Member]

Scenario, Forecast [Member]

Scenario, Forecast [Member]

Long-Term Liabilites [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Monetary production payment

$166,667,000

$25,000,000

$125,000,000

$25,000,000

'

'

'

'

'

'

'

'

'

'

'

Additional monetary production payment implied cost

'

8.75%

10.00%

9.75%

'

'

'

'

'

'

'

'

'

'

'

Principal payment amount

'

'

'

'

'

'

'

'

5,000,000

'

51,700,000

51,700,000

'

'

'

Expected principal payment

'

'

'

'

'

'

'

'

'

'

'

'

5,800,000

10,000,000

18,000,000

Number of common stock shares warrants can be converted into

'

'

'

'

3,440,000

3,440,000

560,000

560,000

'

700,000

'

'

'

'

'

Warrants exercise price

'

'

'

'

$3.01

$3.01

$3.69

$3.69

'

$5.29

'

'

'

'

'

Warrants expiration date

'

'

'

'

30-Apr-18

'

21-May-18

'

'

'

'

'

'

'

'

Montetary production payment, issuance costs

26,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of issued warrants

$7,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Monetary_Production_Payment_Sc

Monetary Production Payment (Schedule Of Monetary Production Payment Liability) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Monetary Production Payment [Abstract]	'
Monetary production payment	$166,667
Less: current portion	74,167
Long-term monetary production payment	$92,500

Other_Liabilities_Schedule_Of_

Other Liabilities (Schedule Of Other Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Other Liabilities [Abstract]	'	'
Asset retirement obligations	$121,534	$139,821
Long-term derivative liabilities	9,245	7,402
Other	591	469
Total Other Liabilities	$131,370	$147,692

Other_Liabilities_Schedule_Of_1

Other Liabilities (Schedule Of Asset Retirement Obligations) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Other Liabilities [Abstract]	'	'
Carrying amount of Asset retirement obligations as of beginning of period	$176,076	$47,258
Increase (decrease) due to revised estimates	-10,304	102,447
Accretion expense (included in DD&A expense)	23,793	7,542
Impact of foreign currency exchange rate changes	3,205	3,019
Payment of asset retirement obligations	-27,690	-8,521
Liabilities incurred and assumed	5,349	24,331
Carrying amount of asset retirement obligations as of end of period	170,429	176,076
Less: current portion of asset retirement obligations	-48,895	-36,255
Long term asset retirement obligations	$121,534	$139,821

Equity_Common_Stock_Narrative_

Equity (Common Stock) (Narrative) (Details) (USD $)

1 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

Jun. 30, 2012

Dec. 31, 2013

Mar. 31, 2011

Apr. 30, 2011

Jan. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

31-May-12

Underwritten Public Offering [Member]

Underwritten Public Offering [Member]

Warrants Expiring On January 9, 2018 [Member]

Warrants Expiring On January 9, 2018 [Member]

Warrants Expiring On April 30, 2018 [Member]

Warrants Expiring On April 30, 2018 [Member]

Warrants Expiring On May 21, 2018 [Member]

Warrants Expiring On May 21, 2018 [Member]

Warrants Expiring On January 24, 2016 [Member]

Warrants Expiring On January 24, 2016 [Member]

6% Senior Notes [Member]

Equity [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, par value

'

$0.00

'

'

'

'

'

'

'

'

'

'

Common stock, shares authorized

'

125,000,000

'

'

'

'

'

'

'

'

'

'

Number of common stock shares warrants can be converted into

'

'

'

'

1,000,000

'

3,440,000

3,440,000

560,000

560,000

'

2,000,000

Warrants exercise price

'

'

'

'

$7.31

'

$3.01

$3.01

$3.69

$3.69

'

$10.50

Warrants expiration date

'

'

'

'

9-Jan-18

9-Jan-18

30-Apr-18

'

21-May-18

'

24-Jan-16

'

Underwritten public offering description

'In June 2012, we completed an underwritten public offering of 8.6 million shares of common stock at a price of $7.50 per common share ($7.13 per common share, net of underwriting discounts) for net proceeds of $60.8 million.

'

'In March 2011, we completed an underwritten public offering of 11.5 million shares of common stock at a price of $11.00 per common share ($10.34 per common share, net of underwriting discounts) for net proceeds of $118.4 million. In April 2011, we used a portion of the offering proceeds to redeem all $81.25 million of our outstanding 6% senior notes.See Note 26 "Subsequent Events" for a discussion of common stock and warrants issued in 2014.

'

'

'

'

'

'

'

'

'

Number of shares offered

8,600,000

'

11,500,000

'

'

'

'

'

'

'

'

'

Stock price

$7.50

'

$11

'

'

'

'

'

'

'

'

'

Stock price, net of underwriting discount

$7.13

'

$10.34

'

'

'

'

'

'

'

'

'

Senior notes amount

'

'

'

$81.25

'

'

'

'

'

'

'

'

Net proceeds

$60,800,000

'

$118,400,000

'

'

'

'

'

'

'

'

'

Equity_Preferred_Stock_Narrati

Equity (Preferred Stock) (Narrative) (Details) (USD $)	12 Months Ended		12 Months Ended				12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2002	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
	Series B Preferred Stock [Member]	Series B Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]
					Call [Member]	Tenth Anniversary [Member]	Change Of Control [Member]
Preferred Stock [Line Items]	'	'	'	'	'	'	'
Preferred Stock Shares Authorized	'	500,000	'	'	'	'	'
Preferred Stock Shares Outstanding	'	'	37,000	'	'	'	'
Preferred Stock Par Or Stated Value Per Share	'	$0.00	'	'	'	'	'
Common Stock Convertable From Preferred Shares Outstanding	'	'	4,200,000	'	'	'	'
Preferred Stock, Dividend Payment Terms	'	'	'cumulative;compounded quarterly based on the original issue price;payable in cash or common stock, at 4.5% or 4.92%, respectively; andpayable to the preferred stock investors prior to payment of any other dividend on any other shares of our capital stock.	'	'	'	'
Conversion price	'	'	$8.75	'	'	'	'
Cash Dividend Rate	8.00%	'	4.50%	'	'	'	'
Stock Dividend Rate	'	'	4.92%	'	'	'	'
Face Value Of Redeemed Shares	'	'	'	$8	'	'	'
Preferred shares converted to common stock	'	'	'	8,000	'	'	'
Common stock issued upon conversion	'	'	'	900,000	'	'	'
Preferred Stock, Liquidation Preference Per Share	$100	'	$1,000	'	'	'	'
Preferred Stock, Redemption Terms	'	'	'	'	'The Series C Preferred Stock is redeemable for a cash payment of an amount equal to 102% of the sum of the liquidation preference of $1,000 per share plus accrued but unpaid dividends. If we call the Series C Preferred Stock for redemption, the holders have the right to convert their shares into a newly issued preferred stock identical in all respects to the Series C Preferred Stock except that such newly issued preferred stock will not bear a dividend.	'	'
Cash Payment As A Percentage Of Liquidation Preference	'	'	'	'	102.00%	'	115.00%
Internal Rate Of Return To Holders	'	'	'	'	'	'	15.00%
Market Value, Minumum	'	'	'	'	'	$500	'

Equity_Schedule_Of_Common_And_

Equity (Schedule Of Common And Preferred Stock Activity) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Common Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Outstanding at the beginning of the year	46,691,000	37,663,000	24,784,000
Issuance of common stock	'	8,625,000	11,531,000
Exercise of stock options	23,000	'	93,000
Conversion of preferred stock	'	'	914,000
Issuance of stock based compensation	267,000	403,000	341,000
Outstanding at the end of the year	46,981,000	46,691,000	37,663,000
Series B Preferred Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Outstanding at the end of the year	20,000	20,000	20,000
Series C Convertible Preferred Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Outstanding at the beginning of the year	'	'	45,000
Conversion of preferred stock	'	'	900,000
Conversion to common stock	'	'	-8,000
Outstanding at the end of the year	37,000	37,000	37,000
Treasury Stock [Member]	'	'	'
Class of Stock [Line Items]	'	'	'
Outstanding at the end of the year	-72,000	-72,000	-72,000

StockBased_Compensation_Arrang2

Stock-Based Compensation Arrangements (Narrative) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Vesting period	'3 years	'
Compensation cost related to awards not yet recognized.	5	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount	1.2	'
Unrecognized compensation cost, recognition period	'3 years	'
Restricted Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of shares	628	754
Performance Shares [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of shares	707	358
Performance period	'3 years	'
Maximum [Member] | Restricted Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Vesting period	'3 years	'
Maximum [Member] | Performance Shares [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Range Of Shares Percent	200.00%	'
Minimum [Member] | Performance Shares [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Range Of Shares Percent	0.00%	'

StockBased_Compensation_Arrang3

Stock-Based Compensation Arrangements (Schedule Of Outstanding Stock Options) (Details) (Stock Options [Member], USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013
Stock Options [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options outstanding, beginning balance	188
Options excercised	-23
Options Forfeited	-45
Options outstanding, ending balance	120
Currently excercisable	120
Options outstanding, weighted average excercise price per share, beginning balance	$6.72
Options outstanding, weighted average excercise price per share, excercised	$3.78
Options outstanding, weighted average price per share, forfeited	$5.98
Options outstanding, weighted average excercise price per share, ending balance	$7.55
Currently excercisable	$7.55
Options outstanding, weighted average contractual life in years	'4 years 3 months 18 days
Currently exercisable, weighted average contracutal life in years	'4 years 3 months 18 days
Options outstanding, aggregate intrinsic value	$55
Currently exercisable, aggregate intrinsic value	$55

StockBased_Compensation_Arrang4

Stock-Based Compensation Arrangements (Schedule Of Stock Options Outstanding By Exercise Price) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]	'
Number Of Options Outstanding	120
Weighted Average Remaining Contractual Life	'4 years 3 months 18 days
Options Outstanding, Weighted Average Exercise Price Per Share	$7.55
Number Exercisable	120
Options Exercisavle, Weighted Average Exercise Price Per Share	$7.55
Less than $5.00 [Member]	'
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]	'
Upper exercise price	$5
Number Of Options Outstanding	37
Weighted Average Remaining Contractual Life	'5 years
Options Outstanding, Weighted Average Exercise Price Per Share	$3.78
Number Exercisable	37
Options Exercisavle, Weighted Average Exercise Price Per Share	$3.78
$5.00 - $8.00	'
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]	'
Lower exercise price	$5
Upper exercise price	$8
Greater than $8.00	'
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]	'
Lower exercise price	$8
Number Of Options Outstanding	83
Weighted Average Remaining Contractual Life	'4 years
Options Outstanding, Weighted Average Exercise Price Per Share	$9.23
Number Exercisable	83
Options Exercisavle, Weighted Average Exercise Price Per Share	$9.23

StockBased_Compensation_Arrang5

Stock-Based Compensation Arrangements (Restricted Stock) (Details) (Restricted Stock [Member], USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013
Restricted Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Balance outstanding, Number of Shares	754
Granted, Number of Shares	562
Vested, Number of Shares	-393
Forfeited, Nuimber of Shares	-295
Balance outstanding, Number of Shares	628
Total grant date fair value of shares vesting during the period	$3,892
Balance outstanding, Weighted Average Grant Date Fair Value per Share	$10.11
Granted, Weighted Average Grant Date Fair Value per Share	$5.23
Vested, Weighted Average Grant Date Fair Value per Share	$9.90
Forfeited, Weighted Average Grant Date Fair Value per Share	$6.98
Balance outstanding, Weighted Average Grant Date Fair Value per Share	$7.44

StockBased_Compensation_Arrang6

Stock-Based Compensation Arrangements (Schedule Of General And Administrative Expenses) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock-Based Compensation Arrangements [Abstract]	'	'	'
G&A Expenses	$3,607	$4,641	$2,988
Capitalized G&A	1,236	1,634	1,051
Total non-cash stock-based compensation	$4,843	$6,275	$4,039

StockBased_Compensation_Arrang7

Stock-Based Compensation Arrangements (Schedule Of Performance-Based Share Awards) (Details) (Performance Shares [Member], USD $)	12 Months Ended
	Dec. 31, 2013
Performance Shares [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Balance outstanding, Number of Shares	358
Granted, Number of Shares	562
Forfeited, Nuimber of Shares	-213
Balance outstanding, Number of Shares	707
Balance outstanding, Weighted Average Grant Date Fair Value per Share	$16.72
Granted, Weighted Average Grant Date Fair Value per Share	$7.41
Forfeited, Weighted Average Grant Date Fair Value per Share	$11.07
Balance outstanding, Weighted Average Grant Date Fair Value per Share	$11.01

Earnings_Per_Share_Details

Earnings Per Share (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Common shares potentially issuable	24,251	17,872	15,418
Options, Warrants And Stock-Based Compensation [Member]	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Common shares potentially issuable	7,981	2,111	111
Convertible Debt Securities [Member]	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Common shares potentially issuable	12,041	11,532	11,078
Convertible Preferred Stock [Member]	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Common shares potentially issuable	4,229	4,229	4,229

Supplementary_Cash_Flow_Disclo1

Supplementary Cash Flow Disclosures (Narrative) (Details) (USD $)	12 Months Ended						12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2014
				Series C Convertible Preferred Stock [Member]	Common Stock [Member]	Convertible bonds, 11.5% until March 31, 2014 and 7.5% thereafter, due 2016 [Member]	Scenario, Forecast [Member]
Conversion Of Stock [Line Items]	'	'	'	'	'	'	'
Cash paid for income taxes not payable until 2013	$17	'	'	'	'	'	'
Cash paid for income taxes	40	'	'	'	'	'	'
Expected income tax refund amount	'	'	'	'	'	'	21.5
Preferred shares converted to common stock	'	'	'	8,000	'	'	'
Common stock issued upon conversion	'	'	'	'	900,000	'	'
Non-cash interest expense	$7.10	$8.70	$12.80	'	'	'	'
Interest rate	'	'	'	'	'	11.50%	'

Supplementary_Cash_Flow_Disclo2

Supplementary Cash Flow Disclosures (Schedule Of Supplemental Cash Flow Information) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Cash Flow Elements [Abstract]	'	'	'
Interest paid	$94,941	$66,365	$31,928
Income taxes paid	$57,132	$426	$9,427

Financial_Instruments_Details

Financial Instruments (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financial Instruments [Abstract]	'	'
Debt, Fair Value	$868,406	$869,488
Debt, Carrying Value	870,878	859,506
Derivative instruments, Fair Value	9,245	7,402
Derivative instruments, Carrying Value	$9,245	$7,402

Related_Parties_Transactions_D

Related Parties Transactions (Details) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Related Party Transaction [Line Items]	'	'	'		'
Maximum credit amount	$125,000,000	'	'		'
Borrowed amount	15,000,000	'	'		'
Debt issuance costs	'	25,210,000	32,204,000	[1]	11,401,000	[1]
Director [Member]	'	'	'		'
Related Party Transaction [Line Items]	'	'	'		'
Debt issuance costs	'	$1,250,000	'		'
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Fair_Value_Measurements_Schedu

Fair Value Measurements (Schedule Of Valuations Of Investments And Financial Instruments) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Embedded derivatives	($9,245,000)	($7,402,000)
Total derivative liabilities	-9,245,000	-7,402,000
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Embedded derivatives	-9,245,000	-7,402,000
Total derivative liabilities	-9,245,000	-7,402,000
Amount of increase or decrease in liability based on stock volatilty	$500,000	'
Fair Value, Inputs, Level 3 [Member] | Oil And Gas Commodity Derivatives [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Volatilty rate, increase or decrease	5.00%	'

Fair_Value_Measurements_Schedu1

Fair Value Measurements (Schedule Of Reconciliation Of Fair Value Of Derivative Assets And Liabilities) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value Measurements [Abstract]	'	'
Balance at beginning of period	($7,402)	($15,858)
Total gains of losses (realized/unrealized) included in earnings	-1,843	8,456
Balance at end of period	-9,245	-7,402
Changes in unrealized gains (losses) relating to derivatives assets and liabilities still held at the end of the period	($1,843)	$8,665

Derivative_Instruments_Schedul

Derivative Instruments (Schedule Of Fair Market Value Of Derivative Instruments Included On The Balance Sheet) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Embedded derivatives	($9,245)	($7,402)
Oil And Gas Commodity Derivatives [Member] | Other Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Embedded derivatives	($9,245)	($7,402)

Derivative_Instruments_Schedul1

Derivative Instruments (Schedule Of Effect Of Derivatives Not Designated As Hedges On Results Of Operations) (Details) (Not Designated as Hedging Instrument [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Oil And Gas Commodity Derivatives [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Unrealized Gain (Loss) on Derivatives	'	($3,524)	($3,050)
Embedded Derivative Financial Instruments [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Unrealized Gain (Loss) on Derivatives	($1,843)	$8,665	$11,428

Recovered_Sheet2

Commitments and Contingencies (Decommissioning Security Agreements) (Narrative) (Details) (USD $)	Sep. 30, 2012	Jan. 31, 2013	Dec. 31, 2013	Jan. 09, 2013	Jan. 09, 2013	Mar. 31, 2012	Mar. 01, 2014	Jan. 24, 2014
		Warrants Expiring On January 9, 2018 [Member]	Warrants Expiring On January 9, 2018 [Member]	Procurement Agreement [Member]	IVRRH Reimbursement Agreement [Member]	IVRRH Reimbursement Agreement [Member]	Subsequent Event [Member]	Subsequent Event [Member]
								Procurement Agreement [Member]
Commitments And Contingencies [Line Items]	'	'	'	'	'	'	'	'
Maximum credit amount	$125,000,000	'	'	$33,000,000	'	'	'	'
Quarterly fee percentage	'	'	'	9.00%	'	'	'	'
Initial fee percentage	'	'	'	1.00%	'	'	'	'
Termination fee percentage	'	'	'	2.00%	'	'	'	'
Annual fee percentage	'	'	'	0.65%	'	'	'	'
Number of common stock shares warrants can be converted into	'	1,000,000	'	'	'	'	700,000	'
Warrants exercise price	'	$7.31	'	'	'	$10.50	$5.29	'
Warrants expiration date	'	9-Jan-18	9-Jan-18	'	'	'	'	'
Reimbursement agreement, outstanding and accrued fees	'	'	'	'	3,800,000	'	'	'
LOC Procurement Agreement, outstanding and accrued fees	'	'	'	'	'	'	'	$201,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Reimbursement Agreement) (Narrative) (Details) (USD $)	3 Months Ended			3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2012	Jan. 09, 2013	Mar. 31, 2012	Jun. 30, 2012	Mar. 01, 2014	Jan. 24, 2014
	IVRRH Reimbursement Agreement [Member]	IVRRH Reimbursement Agreement [Member]	IVRRH Reimbursement Agreement [Member]	Alba Reimbursement Agreement [Member]	Subsequent Event [Member]	Subsequent Event [Member]
						Alba Reimbursement Agreement [Member]
Reimbursement Agreement [Line Items]	'	'	'	'	'	'
Reimbursement agreement related to abandonment liabilities	$33	'	'	$120	'	'
Reimbursement agreement related to abandonment liabilities, annual fee	'	'	'	13.00%	'	'
Warrants exercise price	'	'	$10.50	'	$5.29	'
Reimbursement agreement, outstanding and accrued fees	'	$3.80	'	'	'	$122

Commitments_and_Contingencies_2

Commitments and Contingencies (Terminated Acquisition Of Marcellus Assets) (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended					0 Months Ended
In Thousands, unless otherwise specified	Jul. 31, 2011	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011		Dec. 14, 2011
							SM Energy Company
Business Combination, Separately Recognized Transactions [Line Items]	'	'	'		'		'
Payment to acquire acquisitions	$110,000	$2,787	$238,854	[1]	$33,075	[1]	'
Termination date	'	'	'		'		'December 14, 2011
Counterclaim amount	'	$6,000	'		'		'
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Commitments_and_Contingencies_3

Commitments and Contingencies (Schedule Of Operating Leases) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments and Contingencies [Abstract]	'
2014	$1,723
2015	1,743
2016	1,516
2017	255
Thereafter	'

Recovered_Sheet3

Segment and Geographic Information (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

segment

Revenues From External Customers And Long Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

$116,926

[1]

$36,901

[1]

$126,165

[1]

$57,672

[1]

$97,615

[2],[3]

$83,275

[2],[3]

$23,003

[2],[3]

$15,166

[2],[3]

$337,664

$219,058

$60,091

Long-Lived Assets

1,364,611

'

'

'

1,316,111

'

'

'

1,364,611

1,316,111

791,466

Number of reportable segments

'

'

'

'

'

'

'

'

1

'

'

United States [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenues From External Customers And Long Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

8,368

11,877

18,337

Long-Lived Assets

113,888

'

'

'

123,977

'

'

'

113,888

123,977

139,236

United Kingdom [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenues From External Customers And Long Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

329,296

207,181

41,754

Long-Lived Assets

1,247,248

'

'

'

1,189,870

'

'

'

1,247,248

1,189,870

650,943

Other Countires [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenues From External Customers And Long Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Long-Lived Assets

3,475

'

'

'

2,264

'

'

'

3,475

2,264

1,287

Total International [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenues From External Customers And Long Lived Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

329,296

207,181

41,754

Long-Lived Assets

$1,250,723

'

'

'

$1,192,134

'

'

'

$1,250,723

$1,192,134

$652,230

[1]

Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.

[2]

Includes impairments of oil and gas properties of $15.7 million, $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.

[3]

Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxesin prior periods that was not material to the current year operations.

Quarterly_Financial_Data_Detai

Quarterly Financial Data (Details) (USD $)

3 Months Ended

12 Months Ended

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Revenues

$116,926,000

[1]

$36,901,000

[1]

$126,165,000

[1]

$57,672,000

[1]

$97,615,000

[2],[3]

$83,275,000

[2],[3]

$23,003,000

[2],[3]

$15,166,000

[2],[3]

$337,664,000

$219,058,000

$60,091,000

Operating expenses

87,922,000

[1]

44,899,000

[1]

94,908,000

[1]

49,453,000

[1]

59,857,000

[2],[3]

64,174,000

[2],[3]

41,359,000

[2],[3]

33,867,000

[2],[3]

105,444,000

58,536,000

17,668,000

Operating profit (loss)

29,004,000

[1]

-7,998,000

[1]

31,257,000

[1]

8,219,000

[1]

37,758,000

[2],[3]

19,101,000

[2],[3]

-18,356,000

[2],[3]

-18,701,000

[2],[3]

60,482,000

19,801,000

-67,614,000

Net income (loss) to common shareholders

-28,118,000

[1]

-40,341,000

[1]

-14,341,000

[1]

-14,502,000

[1]

-6,910,000

[2],[3]

-34,158,000

[2],[3]

-51,264,000

[2],[3]

-35,718,000

[2],[3]

-97,302,000

-128,049,000

-132,969,000

Net loss per common share - basic and diluted

($0.60)

[1]

($0.86)

[1]

($0.30)

[1]

($0.31)

[1]

($0.15)

[2],[3]

($0.73)

[2],[3]

($1.31)

[2],[3]

($0.94)

[2],[3]

($2.07)

($3.01)

($3.70)

Impairment of oil and gas properties

'

6,000,000

'

3,500,000

6,000,000

11,400,000

20,000,000

15,700,000

9,566,000

53,072,000

[4]

65,706,000

[4]

Adjustment to deferred income taxes

'

'

'

'

7,000,000

'

'

'

'

'

'

Endeavour International Corporation [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating profit (loss)

'

'

'

'

'

'

'

'

-2,502,000

-2,629,000

-2,198,000

Net income (loss) to common shareholders

'

'

'

'

'

'

'

'

($86,255,000)

($59,398,000)

($18,050,000)

[1]

Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.

[2]

Includes impairments of oil and gas properties of $15.7 million, $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.

[3]

Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxesin prior periods that was not material to the current year operations.

[4]

Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Guarantor_Subsidiaries_Balance

Guarantor Subsidiaries (Balance Sheet) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
In Thousands, unless otherwise specified
Cash and cash equivalents	$34,742	$59,185	[1]	$106,036	[1]	$99,267	[1]
Accounts receivable	65,171	46,181		'		'
Prepaid expenses and other	60,318	39,067		'		'
Current Assets	160,231	144,433		'		'
Property, plant and equipment, net	1,072,151	1,003,441		'		'
Goodwill	259,238	262,764		211,886		'
Other assets	33,222	49,906		'		'
Total Assets	1,524,842	1,460,544		'		'
Accounts payable	38,033	60,153		'		'
Current maturities of debt	'	15,713		'		'
Deferred revenue	20,965	'		'		'
Monetary production payment, current portion	74,167	'		'		'
Accrued expenses and other	88,625	90,100		'		'
Current Liabilities	221,790	165,966		'		'
Long-term debt	870,878	843,793		'		'
Deferred taxes	146,213	159,959		'		'
Monetary production payment, long-term	92,500	'		'		'
Other liabilities	131,370	147,692		'		'
Total Liabilities	1,462,751	1,317,410		'		'
Series C convertible preferred stock	43,703	43,703		'		'
Stockholder's equity	18,388	99,431		154,079		154,618
Total Liabilities and Equity	1,524,842	1,460,544		'		'
Eliminations [Member]	'	'		'		'
Current receivables due from affiliates	-920,665	-1,058,899		'		'
Current Assets	-920,665	-1,058,899		'		'
Long-term receivables due from affiliates	-500,008	-599,000		'		'
Investments in subsidiaries	-276,728	-177,720		'		'
Total Assets	-1,697,401	-1,835,619		'		'
Current liabilites due to affiliates	-920,672	-1,058,899		'		'
Current Liabilities	-920,672	-1,058,899		'		'
Long-term liabilities due from affiliates	-500,000	-599,000		'		'
Total Liabilities	-1,420,672	-1,657,899		'		'
Stockholder's equity	-276,728	-177,720		'		'
Total Liabilities and Equity	-1,697,401	-1,835,619		'		'
Endeavour International Corporation [Member]	'	'		'		'
Current receivables due from affiliates	853,900	950,210		'		'
Current Assets	853,900	950,210		'		'
Investments in subsidiaries	57,662	57,662		'		'
Other assets	20,518	25,200		'		'
Total Assets	932,080	1,033,072		'		'
Current liabilites due to affiliates	648	34,509		'		'
Accrued expenses and other	27,474	27,548		'		'
Current Liabilities	28,122	62,057		'		'
Long-term debt	678,850	676,413		'		'
Other liabilities	3,535	3,033		'		'
Total Liabilities	710,507	741,503		'		'
Series C convertible preferred stock	43,703	43,703		'		'
Stockholder's equity	177,870	247,866		'		'
Total Liabilities and Equity	932,080	1,033,072		'		'
Combined Guarantor Subsidiaries [Member]	'	'		'		'
Cash and cash equivalents	2,417	27,800	[1]	2,951	[1]	709	[1]
Accounts receivable	1,832	2,695		'		'
Current receivables due from affiliates	20,783	36,725		'		'
Prepaid expenses and other	594	508		'		'
Current Assets	25,626	67,728		'		'
Property, plant and equipment, net	87,313	92,692		'		'
Long-term receivables due from affiliates	500,000	599,000		'		'
Investments in subsidiaries	219,066	120,058		'		'
Other assets	6,056	6,085		'		'
Total Assets	838,061	885,563		'		'
Accounts payable	1,214	2,622		'		'
Current liabilites due to affiliates	899,853	987,664		'		'
Accrued expenses and other	3,352	1,517		'		'
Current Liabilities	904,419	991,803		'		'
Other liabilities	602	561		'		'
Total Liabilities	905,021	992,364		'		'
Stockholder's equity	-66,960	-106,801		'		'
Total Liabilities and Equity	838,061	885,563		'		'
Combined Non- Guarantor Subsidiaries [Member]	'	'		'		'
Cash and cash equivalents	32,325	31,385	[1]	103,085	[1]	98,558	[1]
Accounts receivable	63,339	43,486		'		'
Current receivables due from affiliates	45,982	71,964		'		'
Prepaid expenses and other	59,724	38,559		'		'
Current Assets	201,370	185,394		'		'
Property, plant and equipment, net	984,838	910,749		'		'
Goodwill	259,238	262,764		'		'
Long-term receivables due from affiliates	8	'		'		'
Other assets	6,648	18,621		'		'
Total Assets	1,452,102	1,377,528		'		'
Accounts payable	36,819	57,531		'		'
Current maturities of debt	'	15,713		'		'
Deferred revenue	20,965	'		'		'
Monetary production payment, current portion	74,167	'		'		'
Current liabilites due to affiliates	20,171	36,726		'		'
Accrued expenses and other	57,799	61,035		'		'
Current Liabilities	209,921	171,005		'		'
Long-term debt	192,028	167,380		'		'
Long-term liabilities due from affiliates	500,000	599,000		'		'
Deferred taxes	146,213	159,959		'		'
Monetary production payment, long-term	92,500	'		'		'
Other liabilities	127,234	144,098		'		'
Total Liabilities	1,267,896	1,241,442		'		'
Stockholder's equity	184,206	136,086		'		'
Total Liabilities and Equity	$1,452,102	$1,377,528		'		'
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Guarantor_Subsidiaries_Income_

Guarantor Subsidiaries (Income Statement) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Revenue

$116,926

[1]

$36,901

[1]

$126,165

[1]

$57,672

[1]

$97,615

[2],[3]

$83,275

[2],[3]

$23,003

[2],[3]

$15,166

[2],[3]

$337,664

$219,058

$60,091

Operating expenses

87,922

[1]

44,899

[1]

94,908

[1]

49,453

[1]

59,857

[2],[3]

64,174

[2],[3]

41,359

[2],[3]

33,867

[2],[3]

105,444

58,536

17,668

DD&A

'

'

'

'

'

'

'

'

143,048

66,564

[4]

26,478

[4]

Impairment of oil and gas properties

'

6,000

'

3,500

6,000

11,400

20,000

15,700

9,566

53,072

[4]

65,706

[4]

G&A expenses

'

'

'

'

'

'

'

'

19,124

21,085

17,853

Income (Loss) From Operations

29,004

[1]

-7,998

[1]

31,257

[1]

8,219

[1]

37,758

[2],[3]

19,101

[2],[3]

-18,356

[2],[3]

-18,701

[2],[3]

60,482

19,801

-67,614

Derivatives:

'

'

'

'

'

'

'

'

'

'

'

Unrealized gains (losses)

'

'

'

'

'

'

'

'

-1,843

5,141

[4]

8,378

[4]

Interest expense

'

'

'

'

'

'

'

'

-104,516

-84,122

-44,893

Letter of credit fees

'

'

'

'

'

'

'

'

-33,425

-21,903

'

Loss on early extinguishment of debt

'

'

'

'

'

'

'

'

'

-21,661

[4]

-402

[4]

Unrealized foreign currency gains (losses)

'

'

'

'

'

'

'

'

'

'

2,188

Other income (expense)

'

'

'

'

'

'

'

'

-9,735

-9,254

597

Other income (expense)

'

'

'

'

'

'

'

'

'

'

-1,591

Loss before taxes

'

'

'

'

'

'

'

'

-89,037

-111,998

-103,934

Income tax (benefit) expense

'

'

'

'

'

'

'

'

6,442

14,228

27,061

Net income (loss)

'

'

'

'

'

'

'

'

-95,479

-126,226

[4]

-130,995

[4]

Preferred stock dividends

'

'

'

'

'

'

'

'

1,823

1,823

1,974

Net income (loss) to common shareholders

-28,118

[1]

-40,341

[1]

-14,341

[1]

-14,502

[1]

-6,910

[2],[3]

-34,158

[2],[3]

-51,264

[2],[3]

-35,718

[2],[3]

-97,302

-128,049

-132,969

Eliminations [Member]

'

'

'

'

'

'

'

'

'

'

'

Derivatives:

'

'

'

'

'

'

'

'

'

'

'

Interest expense

'

'

'

'

'

'

'

'

60,001

38,743

8,588

Other income (expense)

'

'

'

'

'

'

'

'

-60,001

-38,743

'

Other income (expense)

'

'

'

'

'

'

'

'

'

'

-8,588

Income tax (benefit) expense

'

'

'

'

'

'

'

'

'

-6,997

'

Net income (loss)

'

'

'

'

'

'

'

'

'

6,997

[4],[5]

'

Net income (loss) to common shareholders

'

'

'

'

'

'

'

'

'

6,997

'

Endeavour International Corporation [Member]

'

'

'

'

'

'

'

'

'

'

'

G&A expenses

'

'

'

'

'

'

'

'

2,502

2,629

2,198

Income (Loss) From Operations

'

'

'

'

'

'

'

'

-2,502

-2,629

-2,198

Derivatives:

'

'

'

'

'

'

'

'

'

'

'

Unrealized gains (losses)

'

'

'

'

'

'

'

'

-503

-705

[4]

-2,642

[4]

Interest expense

'

'

'

'

'

'

'

'

-81,400

-54,241

-10,623

Loss on early extinguishment of debt

'

'

'

'

'

'

'

'

'

'

-402

[4]

Other income (expense)

'

'

'

'

'

'

'

'

-27

'

'

Other income (expense)

'

'

'

'

'

'

'

'

'

'

-211

Loss before taxes

'

'

'

'

'

'

'

'

-84,432

-57,575

-16,076

Net income (loss)

'

'

'

'

'

'

'

'

-84,432

-57,575

[4]

-16,076

[4]

Preferred stock dividends

'

'

'

'

'

'

'

'

1,823

1,823

1,974

Net income (loss) to common shareholders

'

'

'

'

'

'

'

'

-86,255

-59,398

-18,050

Combined Guarantor Subsidiaries [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

8,368

11,877

18,337

Operating expenses

'

'

'

'

'

'

'

'

7,399

6,968

9,046

DD&A

'

'

'

'

'

'

'

'

4,249

8,603

[4]

11,490

[4]

Impairment of oil and gas properties

'

'

'

'

'

'

'

'

9,566

53,072

[4]

65,706

[4]

G&A expenses

'

'

'

'

'

'

'

'

7,764

9,887

10,789

Income (Loss) From Operations

'

'

'

'

'

'

'

'

-20,610

-66,653

-78,694

Derivatives:

'

'

'

'

'

'

'

'

'

'

'

Interest expense

'

'

'

'

'

'

'

'

2,988

-951

-3,964

Other income (expense)

'

'

'

'

'

'

'

'

57,463

33,796

'

Other income (expense)

'

'

'

'

'

'

'

'

'

'

-678

Loss before taxes

'

'

'

'

'

'

'

'

39,841

-33,808

-83,336

Income tax (benefit) expense

'

'

'

'

'

'

'

'

'

'

3

Net income (loss)

'

'

'

'

'

'

'

'

39,841

-33,808

[4]

-83,339

[4]

Net income (loss) to common shareholders

'

'

'

'

'

'

'

'

39,841

-33,808

-83,339

Combined Non- Guarantor Subsidiaries [Member]

'

'

'

'

'

'

'

'

'

'

'

Revenue

'

'

'

'

'

'

'

'

329,296

207,181

41,754

Operating expenses

'

'

'

'

'

'

'

'

98,045

51,568

8,622

DD&A

'

'

'

'

'

'

'

'

138,799

57,961

[4]

14,988

[4]

G&A expenses

'

'

'

'

'

'

'

'

8,858

8,569

4,866

Income (Loss) From Operations

'

'

'

'

'

'

'

'

83,594

89,083

13,278

Derivatives:

'

'

'

'

'

'

'

'

'

'

'

Unrealized gains (losses)

'

'

'

'

'

'

'

'

-1,340

5,846

[4]

11,020

[4]

Interest expense

'

'

'

'

'

'

'

'

-86,105

-67,673

-38,894

Letter of credit fees

'

'

'

'

'

'

'

'

-33,425

-21,903

'

Loss on early extinguishment of debt

'

'

'

'

'

'

'

'

'

-21,661

[4]

'

Unrealized foreign currency gains (losses)

'

'

'

'

'

'

'

'

'

'

2,189

Other income (expense)

'

'

'

'

'

'

'

'

-7,170

-4,307

'

Other income (expense)

'

'

'

'

'

'

'

'

'

'

7,885

Loss before taxes

'

'

'

'

'

'

'

'

-44,446

-20,615

-4,522

Income tax (benefit) expense

'

'

'

'

'

'

'

'

6,442

21,225

27,058

Net income (loss)

'

'

'

'

'

'

'

'

-50,888

-41,840

[4]

-31,580

[4]

Net income (loss) to common shareholders

'

'

'

'

'

'

'

'

($50,888)

($41,840)

($31,580)

[1]

Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.

[2]

Includes impairments of oil and gas properties of $15.7 million, $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.

[3]

Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxesin prior periods that was not material to the current year operations.

[4]

Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

[5]

The $7.0 million adjustment reflects the correction of an immaterial error in deferred income taxes that was corrected to beginning stockholder’s equity as of January 1, 2010 in the separate financials of the non-guarantor subsidiaries but reflected in the current year statement of operations for Endeavour.

Guarantor_Subsidiaries_Cash_Fl

Guarantor Subsidiaries (Cash Flow Statement) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Cash Flows from Operating Activities:	'		'		'
Net loss	($95,479)		($126,226)	[1]	($130,995)	[1]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
DD&A	143,048		66,564	[1]	26,478	[1]
Impairment of oil and gas properties	9,566		53,072	[1]	65,706	[1]
Deferred tax benefit	-14,255		-17,594	[1]	21,116	[1]
Unrealized (gains) losses on derivatives	1,843		-5,141	[1]	-8,378	[1]
Amortization of non-cash compensation	3,606		4,401	[1]	3,697	[1]
Amortization of loan costs and discount	22,359		14,179	[1]	12,234	[1]
Non-cash interest expense	7,082		8,684	[1]	12,811	[1]
Loss on early extinguishment of debt	'		21,661	[1]	402	[1]
Other	16,330		15,365	[1]	1,518	[1]
Changes in operating assets and liabilities:	'		'		'
(Increase) decrease in receivables	-18,991		-24,319	[1]	-531	[1]
(Increase) decrease in other current assets	1,324		-592	[1]	-13,328	[1]
Increase (decrease) in liabilities	-18,985		28,559	[1]	-30,073	[1]
Net Cash Provided by (Used in) Operating Activities	57,448		38,613	[1]	-39,343	[1]
Cash Flows From Investing Activities:	'		'		'
Capital expenditures	-225,755		-246,925	[1]	-165,062	[1]
Acquisitions, net of cash acquired	-2,787		-238,854	[1]	-33,075	[1]
Proceeds from sales, net of cash	6,774		1,407	[1]	'
(Increase) decrease in restricted cash	'		-178	[1]	31,726	[1]
Net Cash Used in Investing Activities	-221,768		-484,550	[1]	-166,411	[1]
Cash Flows From Financing Activities:	'		'		'
Repayments of borrowings	'		-274,629	[1]	-103,225	[1]
Borrowings under debt agreements, net of debt discount	'		654,023	[1]	210,000	[1]
Proceeds from issuance of MPP	175,000		'		'
Repayments of MPP	-8,333		'		'
Proceeds from issuance of common stock	'		60,805	[1]	118,444	[1]
Payments for early extinguishment of debt	'		-7,248	[1]	'
Financing costs paid	-25,210		-32,204	[1]	-11,401	[1]
Other financing	-1,580		-1,661	[1]	-1,295	[1]
Net Cash Provided by (Used in) Financing Activities	139,877		399,086	[1]	212,523	[1]
Net Change in Cash and Cash Equivalents	-24,443		-46,851	[1]	6,769	[1]
Cash and Cash Equivalents, Beginning of Period	59,185	[1]	106,036	[1]	99,267	[1]
Cash and Cash Equivalents, End of Period	34,742		59,185	[1]	106,036	[1]
Eliminations [Member]	'		'		'
Cash Flows from Operating Activities:	'		'		'
Net loss	'		6,997	[1],[2]	'
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
Deferred tax benefit	'		-6,997	[1],[2]	'
Amortization of non-cash compensation	2,984	[2]	3,547	[1],[2]	3,073	[1],[2]
Changes in operating assets and liabilities:	'		'		'
Increase (decrease) in liabilities	19,038	[2]	-38,459	[1],[2]	-2,670	[1],[2]
Net Cash Provided by (Used in) Operating Activities	22,022	[2]	-34,912	[1],[2]	403	[1],[2]
Cash Flows From Investing Activities:	'		'		'
Capital expenditures	1,237	[2]	'		'
Issuance of note receivable to affiliates	'		500,000	[1],[2]	'
Net Cash Used in Investing Activities	1,237	[2]	500,000	[1],[2]	'
Cash Flows From Financing Activities:	'		'		'
Borrowings from affiliates	'		-500,000	[1],[2]	'
Financing costs paid	11,286	[2]	'		'
Intercompany cash management	-34,545	[2]	34,912	[1],[2]	-403	[1],[2]
Net Cash Provided by (Used in) Financing Activities	-23,259	[2]	-465,088	[1],[2]	-403	[1],[2]
Endeavour International Corporation [Member]	'		'		'
Cash Flows from Operating Activities:	'		'		'
Net loss	-84,432		-57,575	[1]	-16,076	[1]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
Unrealized (gains) losses on derivatives	503		705	[1]	2,642	[1]
Amortization of non-cash compensation	622		854	[1]	624	[1]
Amortization of loan costs and discount	7,826		6,908	[1]	1,049	[1]
Non-cash interest expense	'		445	[1]	880	[1]
Loss on early extinguishment of debt	'		'		402	[1]
Other	44		283	[1]	-82	[1]
Changes in operating assets and liabilities:	'		'		'
(Increase) decrease in other current assets	'		'		34	[1]
Net Cash Provided by (Used in) Operating Activities	-75,437		-48,380	[1]	-10,527	[1]
Cash Flows From Financing Activities:	'		'		'
Repayments of borrowings	'		-32,457	[1]	-101,250	[1]
Borrowings under debt agreements, net of debt discount	'		538,860	[1]	135,000	[1]
Proceeds from issuance of common stock	'		60,805	[1]	118,444	[1]
Financing costs paid	-700		-24,141	[1]	-5,926	[1]
Intercompany cash management	77,874		-493,026	[1]	-134,457	[1]
Other financing	-1,737		-1,661	[1]	-1,284	[1]
Net Cash Provided by (Used in) Financing Activities	75,437		48,380	[1]	10,527	[1]
Combined Guarantor Subsidiaries [Member]	'		'		'
Cash Flows from Operating Activities:	'		'		'
Net loss	39,841		-33,808	[1]	-83,339	[1]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
DD&A	4,249		8,603	[1]	11,490	[1]
Impairment of oil and gas properties	9,566		53,072	[1]	65,706	[1]
Amortization of loan costs and discount	'		5	[1]	-403	[1]
Non-cash interest expense	-12,958		'		'
Other	12,942		173	[1]	105	[1]
Changes in operating assets and liabilities:	'		'		'
(Increase) decrease in receivables	863		1,495	[1]	-1,597	[1]
(Increase) decrease in other current assets	-14,252		-9,223	[1]	2,872	[1]
Increase (decrease) in liabilities	-13,628		88,635	[1]	-39,135	[1]
Net Cash Provided by (Used in) Operating Activities	26,623		108,952	[1]	-44,301	[1]
Cash Flows From Investing Activities:	'		'		'
Capital expenditures	-15,111		-39,794	[1]	-80,279	[1]
Acquisitions, net of cash acquired	65		-2,372	[1]	-8,027	[1]
Proceeds from sales, net of cash	6,712		'		'
Issuance of note receivable to affiliates	'		-500,000	[1]	'
(Increase) decrease in restricted cash	'		-50	[1]	'
Net Cash Used in Investing Activities	-8,335		-542,216	[1]	-88,306	[1]
Cash Flows From Financing Activities:	'		'		'
Financing costs paid	-500		'		'
Intercompany cash management	-43,329		458,114	[1]	134,860	[1]
Other financing	157		'		-11	[1]
Net Cash Provided by (Used in) Financing Activities	-43,672		458,114	[1]	134,849	[1]
Net Change in Cash and Cash Equivalents	-25,383		24,849	[1]	2,242	[1]
Cash and Cash Equivalents, Beginning of Period	27,800	[1]	2,951	[1]	709	[1]
Cash and Cash Equivalents, End of Period	2,417		27,800	[1]	2,951	[1]
Combined Non- Guarantor Subsidiaries [Member]	'		'		'
Cash Flows from Operating Activities:	'		'		'
Net loss	-50,888		-41,840	[1]	-31,580	[1]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'		'		'
DD&A	138,799		57,961	[1]	14,988	[1]
Deferred tax benefit	-14,255		-10,597	[1]	21,116	[1]
Unrealized (gains) losses on derivatives	1,340		-5,846	[1]	-11,020	[1]
Amortization of loan costs and discount	14,533		7,266	[1]	11,588	[1]
Non-cash interest expense	20,040		8,239	[1]	11,931	[1]
Loss on early extinguishment of debt	'		21,661	[1]	'
Other	3,344		14,909	[1]	1,495	[1]
Changes in operating assets and liabilities:	'		'		'
(Increase) decrease in receivables	-19,854		-25,814	[1]	1,066	[1]
(Increase) decrease in other current assets	15,576		8,631	[1]	-16,234	[1]
Increase (decrease) in liabilities	-24,395		-21,617	[1]	11,732	[1]
Net Cash Provided by (Used in) Operating Activities	84,240		12,953	[1]	15,082	[1]
Cash Flows From Investing Activities:	'		'		'
Capital expenditures	-211,881		-207,131	[1]	-84,783	[1]
Acquisitions, net of cash acquired	-2,852		-236,482	[1]	-25,048	[1]
Proceeds from sales, net of cash	62		1,407	[1]	'
(Increase) decrease in restricted cash	'		-128	[1]	31,726	[1]
Net Cash Used in Investing Activities	-214,670		-442,334	[1]	-78,105	[1]
Cash Flows From Financing Activities:	'		'		'
Repayments of borrowings	'		-242,172	[1]	-1,975	[1]
Borrowings under debt agreements, net of debt discount	'		115,163	[1]	75,000	[1]
Borrowings from affiliates	'		500,000	[1]	'
Proceeds from issuance of MPP	175,000		'		'
Repayments of MPP	-8,333		'		'
Payments for early extinguishment of debt	'		-7,248	[1]	'
Financing costs paid	-35,296		-8,063	[1]	-5,475	[1]
Net Cash Provided by (Used in) Financing Activities	131,371		357,680	[1]	67,550	[1]
Net Change in Cash and Cash Equivalents	940		-71,700	[1]	4,527	[1]
Cash and Cash Equivalents, Beginning of Period	31,385	[1]	103,085	[1]	98,558	[1]
Cash and Cash Equivalents, End of Period	$32,325		$31,385	[1]	$103,085	[1]
[1]	Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.
[2]	The $7.0 million adjustment reflects the correction of an immaterial error in deferred income taxes that was corrected to beginning stockholder’s equity as of January 1, 2010 in the separate financials of the non-guarantor subsidiaries but reflected in the current year statement of operations for Endeavour.

Subsequent_Events_Details

Subsequent Events (Details)

0 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

Apr. 12, 2012

Sep. 30, 2012

Mar. 01, 2014

Dec. 31, 2013

Dec. 31, 2013

Jan. 24, 2014

Jan. 24, 2014

Jan. 24, 2014

Jan. 24, 2014

Jan. 24, 2014

Dec. 31, 2013

Jan. 24, 2014

Jan. 24, 2014

Dec. 31, 2013

Jan. 24, 2014

Jan. 24, 2014

Feb. 28, 2014

Jan. 24, 2014

Dec. 31, 2013

Dec. 31, 2013

Mar. 01, 2014

USD ($)

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Convertible Senior Notes, 5.5% Fixed Rate, Due 2016 [Member]

6.5% Convertible Notes [Member]

6.5% Convertible Notes [Member]

USD ($)

Term Loan Facility [Member]

Term Loan Facility [Member]

Term Loan Facility [Member]

Revolving Credit Facility [Member]

Combined Procurement Agreement [Member]

Combined Procurement Agreement [Member]

Combined Procurement Agreement [Member]

Combined Procurement Agreement [Member]

Alba Field [Member]

Alba Field [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Subsequent Event [Member]

USD ($)

London Interbank Offered Rate (LIBOR) [Member]

USD ($)

USD ($)

GBP (£)

London Interbank Offered Rate (LIBOR) [Member]

USD ($)

USD ($)

Term Loan Facility [Member]

Term Loan Facility [Member]

USD ($)

Term Loan Facility [Member]

USD ($)

London Interbank Offered Rate (LIBOR) [Member]

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility initiation date

12-Apr-12

'

'

'

24-Jan-14

'

'

'

'

'

24-Jan-14

'

'

'

'

'

'

'

'

'

'

Maximum credit amount

'

$125,000,000

'

'

'

$255,000,000

'

'

$130,000,000

£ 78,000,000

'

'

'

'

'

'

'

'

'

'

'

Amount of term loan facility advanced

'

'

'

'

'

125,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepayment fee and accrued interest

'

'

'

'

'

'

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Basis spread on variable rate

'

'

'

'

'

'

7.00%

'

'

'

'

7.00%

'

'

'

'

'

'

'

'

'

Interest rate

'

'

'

'

'

'

'

'

'

'

'

1.25%

'

'

'

1.25%

'

'

5.50%

'

6.50%

Maturity date

'

'

'

'

30-Nov-17

'

'

'

'

'

30-Nov-17

'

'

'

'

'

'

'

'

30-Nov-17

'

Minimum interest coverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

150.00%

'

'

'

'

'

'

Leverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500.00%

'

'

'

Asset coverage ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200.00%

'

'

'

'

'

'

Amount outstanding

'

'

'

'

'

'

'

'

'

'

'

'

55,000,000

120,000,000

'

'

'

'

'

'

'

Discount rate

'

'

'

'

'

'

'

'

98.50%

98.50%

'

'

'

'

'

'

'

'

'

'

'

Value of common stock, warrants and convertible notes issued

'

'

30,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

55,000,000

'

'

'

'

Common stock, shares issued

'

'

2,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of common stock shares warrants can be converted into

'

'

700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants exercise price

'

'

$5.29

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt principal amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,500,000

Option purchase period

'

'

'

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Value of options to purchase additional shares

'

'

$25,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of common stock

'

'

20.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion rate

'

'

4.662

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion price

'

'

$4.66

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recovered_Sheet4

Supplemental Oil and Gas Disclosures (Narrative) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
	MBoe	MBoe	MBoe	MBoe
Supplemental Oil And Gas Disclosures [Abstract]	'	'	'	'
Proved reserves	23,538,000	25,671,000	22,718,000	18,382,000
Discount Rate Applied To Cash Flow Amounts In Computation Of Standardized Measure Of Discounted Future Net Cash Flows	10.00%	'	'	'

Recovered_Sheet5

Supplemental Oil and Gas Disclosures (Capitalized Costs) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]	'	'
Proved	$1,084,668	$915,801
Unproved	368,661	349,433
Total capitalized costs	1,453,329	1,265,234
Accumulated depreciation, depletion and amortization	-382,795	-265,607
Net capitalized costs	1,070,534	999,627
United Kingdom [Member]	'	'
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]	'	'
Proved	1,043,927	876,536
Unproved	295,083	273,298
Total capitalized costs	1,339,010	1,149,834
Accumulated depreciation, depletion and amortization	-355,366	-241,338
Net capitalized costs	983,644	908,496
United States [Member]	'	'
Capitalized Costs Relating To Oil And Gas Producing Activities By Geographic Area [Line Items]	'	'
Proved	40,741	39,265
Unproved	73,578	76,135
Total capitalized costs	114,319	115,400
Accumulated depreciation, depletion and amortization	-27,429	-24,269
Net capitalized costs	$86,890	$91,131

Supplemental_Oil_and_Gas_Discl2

Supplemental Oil and Gas Disclosures (Costs Incurred) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Costs Incurred Oil And Gas Property Acquisition Exploration And Development Activities [Line Items]	'	'	'
Proved	'	$144,180	$2,595
Unproved	2,786	48,034	48,947
Exploration costs	50,846	62,127	127,700
Development costs	149,773	310,137	90,458
Total costs incurred	203,405	564,478	269,700
United Kingdom [Member]	'	'	'
Costs Incurred Oil And Gas Property Acquisition Exploration And Development Activities [Line Items]	'	'	'
Proved	'	143,004	2,595
Unproved	2,323	46,878	46,107
Exploration costs	39,202	46,730	51,820
Development costs	146,685	302,038	79,898
Total costs incurred	188,210	538,650	180,420
United States [Member]	'	'	'
Costs Incurred Oil And Gas Property Acquisition Exploration And Development Activities [Line Items]	'	'	'
Proved	'	1,176	'
Unproved	463	1,156	2,840
Exploration costs	11,644	15,397	75,880
Development costs	3,088	8,099	10,560
Total costs incurred	$15,195	$25,828	$89,280

Supplemental_Oil_and_Gas_Discl3

Supplemental Oil and Gas Disclosures (Results of Ops) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Results Of Operations For Oil And Gas Producing Activities By Geographic Area [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

$116,926

[1]

$36,901

[1]

$126,165

[1]

$57,672

[1]

$97,615

[2],[3]

$83,275

[2],[3]

$23,003

[2],[3]

$15,166

[2],[3]

$337,664

$219,058

$60,091

Production expenses

87,922

[1]

44,899

[1]

94,908

[1]

49,453

[1]

59,857

[2],[3]

64,174

[2],[3]

41,359

[2],[3]

33,867

[2],[3]

105,444

58,536

17,668

DD&A

'

'

'

'

'

'

'

'

140,981

64,387

25,025

Impairment of oil and gas properties

'

6,000

'

3,500

6,000

11,400

20,000

15,700

9,566

53,072

[4]

65,706

[4]

Income tax expense (benefit)

'

'

'

'

'

'

'

'

53,833

41,748

-12,391

Results of activities

'

'

'

'

'

'

'

'

27,840

1,315

-35,917

United Kingdom [Member]

'

'

'

'

'

'

'

'

'

'

'

Results Of Operations For Oil And Gas Producing Activities By Geographic Area [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

329,296

207,181

41,754

Production expenses

'

'

'

'

'

'

'

'

98,045

51,568

8,622

DD&A

'

'

'

'

'

'

'

'

137,739

56,813

14,312

Income tax expense (benefit)

'

'

'

'

'

'

'

'

57,977

61,256

11,104

Results of activities

'

'

'

'

'

'

'

'

35,535

37,544

7,716

United States [Member]

'

'

'

'

'

'

'

'

'

'

'

Results Of Operations For Oil And Gas Producing Activities By Geographic Area [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

8,368

11,877

18,337

Production expenses

'

'

'

'

'

'

'

'

7,399

6,968

9,046

DD&A

'

'

'

'

'

'

'

'

3,242

7,574

10,713

Impairment of oil and gas properties

'

'

'

'

'

'

'

'

9,566

53,072

65,706

Income tax expense (benefit)

'

'

'

'

'

'

'

'

-4,144

-19,508

-23,495

Results of activities

'

'

'

'

'

'

'

'

($7,695)

($36,229)

($43,633)

[1]

Includes impairments of oil and gas properties of $3.5 million and $6.0 million for the first and third quarters of 2013, respectively.

[2]

Includes impairments of oil and gas properties of $15.7 million, $20.0 million, $11.4 million and $6.0 million, for the first, second, third and fourth quarters of 2012, respectively.

[3]

Includes $7.0 million in the fourth quarter of 2012 related to the correction of an error in deferred income taxesin prior periods that was not material to the current year operations.

[4]

Revised to reflect intercompany cash management activities previously presented cash flows from operations in “Cash Flows From Financing Activities.” There was no impact to Consolidated balances.

Supplemental_Oil_and_Gas_Discl4

Supplemental Oil and Gas Disclosures (Reserves Volume) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	MBbls	MBbls	MBbls
Oil Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	13,739,000	4,101,000	3,723,000
Production	-3,018,000	-1,997,000	-380,000
Purchases of reserves	'	11,071,000	'
Sale of reserves in place	'	-19,000	'
Extensions and discoveries	'	1,992,000	303,000
Revisions of previous estimates	1,621,000	-1,409,000	455,000
Proved reserves closing balance	12,342,000	13,739,000	4,101,000
Proved Developed Reserves	5,661,000	5,267,000	1,311,000
Natural Gas Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	71,591,000	111,701,000	87,954,000
Production	-3,830,000	-5,297,000	-5,170,000
Purchases of reserves	'	2,407,000	90,000
Sale of reserves in place	-4,200,000	-5,213,000	'
Extensions and discoveries	'	473,000	46,100,000
Revisions of previous estimates	3,612,000	-32,480,000	-17,273,000
Proved reserves closing balance	67,173,000	71,591,000	111,701,000
Proved Developed Reserves	28,176,000	17,837,000	23,499,000
United Kingdom [Member] | Oil Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	13,733,000	4,060,000	3,664,000
Production	-3,017,000	-1,994,000	-373,000
Purchases of reserves	'	11,071,000	'
Extensions and discoveries	'	1,992,000	303,000
Revisions of previous estimates	1,624,000	-1,396,000	466,000
Proved reserves closing balance	12,340,000	13,733,000	4,060,000
Proved Developed Reserves	5,659,000	5,261,000	1,270,000
United Kingdom [Member] | Natural Gas Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	56,901,000	50,723,000	56,177,000
Production	-1,194,000	-91,000	-94,000
Purchases of reserves	'	1,409,000	90,000
Extensions and discoveries	'	473,000	'
Revisions of previous estimates	-309,000	4,387,000	-5,450,000
Proved reserves closing balance	55,398,000	56,901,000	50,723,000
Proved Developed Reserves	18,384,000	3,147,000	795,000
United States [Member] | Oil Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	6,000	41,000	59,000
Production	-1,000	-3,000	-7,000
Sale of reserves in place	'	-19,000	'
Revisions of previous estimates	-3,000	-13,000	-11,000
Proved reserves closing balance	2,000	6,000	41,000
Proved Developed Reserves	2,000	6,000	41,000
United States [Member] | Natural Gas Reserves [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	14,690,000	60,978,000	31,777,000
Production	-2,636,000	-5,206,000	-5,076,000
Purchases of reserves	'	998,000	'
Sale of reserves in place	-4,200,000	-5,213,000	'
Extensions and discoveries	'	'	46,100,000
Revisions of previous estimates	3,921,000	-36,867,000	-11,823,000
Proved reserves closing balance	11,775,000	14,690,000	60,978,000
Proved Developed Reserves	9,792,000	14,690,000	22,704,000

Supplemental_Oil_and_Gas_Discl5

Supplemental Oil and Gas Disclosures (Reserves MBBoe) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	MBoe	MBoe	MBoe
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	25,671,000	22,718,000	18,382,000
Production	-3,656,000	-2,880,000	-1,242,000
Extensions and discoveries	'	2,071,000	7,683,000
Purchases of proved reserves, in place	'	11,472,000	318,000
Sale of reserves	-700,000	-888,000	'
Revisions of previous estimates	2,223,000	-6,822,000	-2,423,000
Proved reserves closing balance	23,538,000	25,671,000	22,718,000
Proved Developed Oil and Gas Reserves (MMBoe):	10,357,000	8,239,000	5,227,000
United Kingdom [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	23,217,000	12,514,000	13,027,000
Production	-3,216,000	-2,009,000	-389,000
Extensions and discoveries	'	2,071,000	'
Purchases of proved reserves, in place	'	11,306,000	318,000
Revisions of previous estimates	1,572,000	-665,000	-442,000
Proved reserves closing balance	21,573,000	23,217,000	12,514,000
Proved Developed Oil and Gas Reserves (MMBoe):	8,723,000	5,785,000	1,402,000
United States [Member]	'	'	'
Reserve Quantities [Line Items]	'	'	'
Proved reserves at opening balance	2,454,000	10,204,000	5,355,000
Production	-440,000	-871,000	-853,000
Extensions and discoveries	'	'	7,683,000
Purchases of proved reserves, in place	'	166,000	'
Sale of reserves	-700,000	-888,000	'
Revisions of previous estimates	651,000	-6,157,000	-1,981,000
Proved reserves closing balance	1,965,000	2,454,000	10,204,000
Proved Developed Oil and Gas Reserves (MMBoe):	1,634,000	2,454,000	3,825,000

Supplemental_Oil_and_Gas_Discl6

Supplemental Oil and Gas Disclosures (Future Cash Inflows) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
United Kingdom [Member]	'	'
Prices Used To Determine Estimate Of Future Cash Inflows Oil	104.45	111.13
Prices Used To Determine Estimate Of Future Cash Inflows Gas	10.38	9.34
United States [Member]	'	'
Prices Used To Determine Estimate Of Future Cash Inflows Oil	97.71	94.71
Prices Used To Determine Estimate Of Future Cash Inflows Gas	2.94	2.75

Supplemental_Oil_and_Gas_Discl7

Supplemental Oil and Gas Disclosures (SM Future Net CS Inflows) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves [Line Items]	'	'
Future cash inflows	$1,896,989	$2,066,466
Future production costs	-583,549	-578,515
Future development costs	-594,563	-582,173
Future income tax expense	-133,495	-277,436
Future net cash inflows (undiscounted)	585,382	628,342
Annual discount of 10% for estimated timing	49,700	129,364
Standarized measure of future net cash flows	535,682	498,978
United Kingdom [Member]	'	'
Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves [Line Items]	'	'
Future cash inflows	1,862,137	2,035,208
Future production costs	-571,347	-568,414
Future development costs	-593,958	-581,277
Future income tax expense	-133,495	-277,436
Future net cash inflows (undiscounted)	563,337	608,081
Annual discount of 10% for estimated timing	43,152	122,780
Standarized measure of future net cash flows	520,185	485,301
United States [Member]	'	'
Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves [Line Items]	'	'
Future cash inflows	34,852	31,258
Future production costs	-12,202	-10,101
Future development costs	-605	-896
Future net cash inflows (undiscounted)	22,045	20,261
Annual discount of 10% for estimated timing	6,548	6,584
Standarized measure of future net cash flows	$15,497	$13,677

Supplemental_Oil_and_Gas_Discl8

Supplemental Oil and Gas Disclosures (Principal Sources Chg SM) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental Oil And Gas Disclosures [Abstract]	'	'	'
Standarized measure, beginning of period	$498,978	$264,872	$111,297
Net changes in prices and production costs	-33,792	-33,520	147,776
Future development costs incurred	140,436	172,462	76,721
Net changes in estimated future development costs	88,008	-193,359	-9,261
Revisions of previous quantity estimates	'	-56,525	-36,421
Extensions and discoveries	-132,092	102,386	68,452
Accretion of discount	78,151	42,589	18,801
Changes in income taxes, net	104,891	-74,778	-136,157
Sale of oil and gas produced, net of production costs	-232,220	-165,547	-44,556
Purchased reserves	'	457,033	26,340
Sales of reserves in place	-4,074	-6,971	'
Change in production, timing and other	27,396	-9,664	41,880
Standarized measure, end of period	$535,682	$498,978	$264,872