Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

(Amounts in thousands)				U.K.		U.S.		Other		Total
Year Ended December 31, 2012:
	Net income (loss) before taxes		$	(22,959)	$	(91,383)	$	2,344	$	(111,998)
	Current tax expense			31,796		-		26		31,822
	Deferred tax expense related
		to U.K. tax rate change		8,587		-		-		8,587
	Deferred tax benefit			(26,181)		-		-		(26,181)
	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)
	Current tax expense			5,926		4		15		5,945
	Deferred tax expense related
		to U.K. tax rate change		25,424		-		-		25,424
	Deferred tax benefit			(4,308)		-		-		(4,308)
	Total tax expense			27,042		4		15		27,061
	Net income (loss) after taxes		$	(36,848)	$	(99,413)	$	5,266	$	(130,995)
Year Ended December 31, 2010:
	Net income (loss) before taxes		$	90,160	$	(30,978)	$	(3,439)	$	55,743
	Current tax (benefit) expense			2,734				(154)		2,580
	Deferred tax (benefit) expense			(2,388)				(929)		(3,317)
	Foreign currency losses on
		deferred tax liabilities		-		-		(51)		(51)
	Total tax (benefit) expense			346		-		(1,134)		(788)
	Net income (loss) after taxes		$	89,814	$	(30,978)	$	(2,305)	$	56,531

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

		Year Ended December 31,
		2012		2011		2010
Federal income tax expense (benefit) at statutory rate	$	(39,199)	$	(36,378)	$	19,500
Taxation of foreign operations		5,859		3,254		(579)
Effect of out-of-period adjustment		6,997		-		-
Tax-free gain on sale of reserves in place		-		-		(30,510)
Change in valuation allowance – U.S.		30,329		24,604		(2,252)
U.K. Tax increase from tax law and rate changes		8,587		25,424		-
Foreign currency (gain) loss on deferred taxes		-		-		(50)
Deemed foreign dividend of wholly owned subsidiaries		-		8,572		11,466
Disallowed executive compensation		1,655		1,585		765
Other		-		-		872
Total Income Tax Expense	$	14,228	$	27,061	$	(788)
Effective Income Tax Rate		-13%		-26%		-1%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

		2012		2011
Deferred tax asset:
Deferred compensation	$	2,268	$	5,859
Unrealized loss on commodity derivative instruments		-		1,260
Asset retirement obligation		87,787		29,122
Net operating loss and capital loss carryforward		334,121		157,570
Unrealized loss on embedded derivative instruments		1,084		4,005
Property, plant and equipment		19,596		12,427
Inventory / other		8,089		-
Total deferred tax assets		452,945		210,243
Less valuation allowance		(84,691)		(58,532)
Total deferred tax assets after valuation allowance		368,254		151,711
Deferred tax liability:
Property, plant and equipment		(478,719)		(258,779)
Petroleum revenue tax, net of tax benefit		(22,703)		(229)
Debt discount		(630)		(752)
Other		-		(7,710)
Total deferred tax liabilities		(502,052)		(267,470)
Net deferred tax liability	$	(133,798)	$	(115,759)

Schedule of Tax Attributes Available to Reduce Future Income Taxes [Table Text Block]

			As of December 31,
			2012			2011
		Types of Tax Attributes	Years of Expiration		Carry-forward Amount	Years of Expiration		Carry-forward Amount
U.K.
	Corporate tax	NOL	Indefinite	$	500,789	Indefinite	$	228,701
	Supplemental Corporate tax	NOL	Indefinite		378,602	Indefinite		159,316
U.S.
	Corporate Income tax	NOL	2023 - 2032		177,206	2023 - 2031		106,535
	Capital gains tax	Capital loss	2015		1,848	2015		1,848

Summary of Income Tax Contingencies [Table Text Block]

		Year Ended
		December 31,
		2012		2011		2010
Balance at the beginning of the year	$	-	$	-	$	-
Increase in unrecognized tax benefits from current period tax position		6,820		-		-
Balance at the end of the year	$	6,820	$	-	$	-

Summary Of Income Tax Examinations [Table Text Block]

Tax Jurisdiction
U.K.	2011
All others	2009 - 2011