Guarantor Subsidiaries (Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 130,790	$ 59,185	$ 94,570	$ 106,036
Accounts receivable	28,612	46,181
Prepaid expenses and other	33,933	20,995
Current Assets	193,335	126,361
Property, plant and equipment, net	1,054,834	1,003,441
Goodwill	259,238	262,764
Other assets	39,065	49,906
Total Assets	1,546,472	1,442,472
Current Liabilities:
Accounts payable	72,212	60,153
Current maturities of debt	115,163	15,713
Monetary production payment, current portion	20,833
Accrued expenses and other	96,154	90,100
Current Liabilities	304,362	165,966
Long-term debt	749,894	843,793
Deferred taxes	125,146	141,887
Monetary production payment, long-term	104,167
Other liabilities	134,075	147,692
Total Liabilities	1,417,644	1,299,338
Series C convertible preferred stock	43,703	43,703
Stockholder's equity	85,125	99,431
Total Liabilities and Equity	1,546,472	1,442,472
Endeavour International Corporation [Member]
Current Assets:
Current receivables due from affiliates	913,633	950,210
Current Assets	913,633	950,210
Investments in subsidiaries	57,662	57,662
Other assets	23,213	25,200
Total Assets	994,508	1,033,072
Current Liabilities:
Current liabilites due to affiliates	22,712	34,509
Accrued expenses and other	28,219	27,548
Current Liabilities	50,931	62,057
Long-term debt	677,632	676,413
Other liabilities	3,408	3,033
Total Liabilities	731,971	741,503
Series C convertible preferred stock	43,703	43,703
Stockholder's equity	218,834	247,866
Total Liabilities and Equity	994,508	1,033,072
Combined Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	2,622	27,800	13,412	2,951
Accounts receivable	2,305	2,695
Current receivables due from affiliates	22,459	36,725
Prepaid expenses and other	1,291	508
Current Assets	28,677	67,728
Property, plant and equipment, net	94,711	92,692
Long-term receivables due from affiliates	599,000	599,000
Investments in subsidiaries	120,058	120,058
Other assets	6,056	6,085
Total Assets	848,502	885,563
Current Liabilities:
Accounts payable	3,760	2,622
Current liabilites due to affiliates	928,335	987,664
Accrued expenses and other	2,654	1,517
Current Liabilities	934,749	991,803
Other liabilities	658	561
Total Liabilities	935,407	992,364
Stockholder's equity	(86,905)	(106,801)
Total Liabilities and Equity	848,502	885,563
Combined Non- Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	128,168	31,385	81,158	103,085
Accounts receivable	26,307	43,486
Current receivables due from affiliates	37,414	71,964
Prepaid expenses and other	32,642	20,487
Current Assets	224,531	167,322
Property, plant and equipment, net	960,123	910,749
Goodwill	259,238	262,764
Other assets	9,796	18,621
Total Assets	1,453,688	1,359,456
Current Liabilities:
Accounts payable	68,452	57,531
Current maturities of debt	115,163	15,713
Monetary production payment, current portion	20,833
Current liabilites due to affiliates	22,459	36,726
Accrued expenses and other	65,281	61,035
Current Liabilities	292,188	171,005
Long-term debt	72,262	167,380
Long-term liabilities due to affiliates	599,000	599,000
Deferred taxes	125,146	141,887
Monetary production payment, long-term	104,167
Other liabilities	130,009	144,098
Total Liabilities	1,322,772	1,223,370
Stockholder's equity	130,916	136,086
Total Liabilities and Equity	1,453,688	1,359,456
Eliminations [Member]
Current Assets:
Current receivables due from affiliates	(973,506)	(1,058,899)
Current Assets	(973,506)	(1,058,899)
Long-term receivables due from affiliates	(599,000)	(599,000)
Investments in subsidiaries	(177,720)	(177,720)
Total Assets	(1,750,226)	(1,835,619)
Current Liabilities:
Current liabilites due to affiliates	(973,506)	(1,058,899)
Current Liabilities	(973,506)	(1,058,899)
Long-term liabilities due to affiliates	(599,000)	(599,000)
Total Liabilities	(1,572,506)	(1,657,899)
Stockholder's equity	(177,720)	(177,720)
Total Liabilities and Equity	$ (1,750,226)	$ (1,835,619)