Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2016	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards subject to annual limitations	$ 138,000,000
US state NOLs that we do not anticipate utilizing	173,000,000
EffectiveTaxRateReconciliation [Line Items]
Amount computed using the statutory rate	$ 0.35	$ 0.35	$ 0.35
State and local income taxes, net of federal effect	0.00%	0.90%	1.70%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	0.60%	0.40%	0.20%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	0.50%	0.00%	0.10%
Effective Income Tax Rate Reconciliation, Percent	(1.80%)	32.00%	37.00%
Income (loss) from continuing operations before income taxes	$ (1,208,000,000)	$ (4,947,000,000)	$ 1,032,000,000
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	(13,000,000)	(12,000,000)	0
U.S. state	0	(2,000,000)	2,000,000
Foreign	22,000,000	31,000,000	3,000,000
Deferred taxes:
U.S. federal	10,000,000	(1,507,000,000)	350,000,000
U.S. state	13,000,000	(27,000,000)	25,000,000
Foreign	(10,000,000)	(68,000,000)	2,000,000
Income Tax Expense (Benefit)	22,000,000	(1,585,000,000)	382,000,000
Deferred tax asset:
Net operating loss carryforwards	301,000,000	243,000,000
Alternative minimum tax credit	73,000,000	87,000,000
Stock compensation	15,000,000	23,000,000		$ 37,000,000
Deferred Tax Assets, Property, Plant and Equipment	306,000,000	13,000,000
Deferred Tax Assets, Derivative Instruments	9,000,000	0
Foreign tax credit	593,000,000	572,000,000
Other	13,000,000	17,000,000
Deferred Tax Assets, Gross	1,310,000,000	955,000,000
Valuation Allowance	(1,310,000,000)	(790,000,000)	$ (549,000,000)		$ (584,000,000)
Deferred tax asset	0	165,000,000
Deferred tax liability:
Commodity derivatives	0	(119,000,000)
Deferred Tax Liabilities, Property, Plant and Equipment	(39,000,000)	(72,000,000)
Deferred Tax Liabilities, Gross	(39,000,000)	(191,000,000)
Deferred tax liability	(39,000,000)	(26,000,000)
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	849,000,000	852,000,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 1,800,000,000	$ 1,800,000,000
Domestic [Member]
EffectiveTaxRateReconciliation [Line Items]
Net effect of different tax rates in non-U.S. jurisdictions	(35.50%)	(4.00%)	0.00%
Income (loss) from continuing operations before income taxes	$ (1,181,000,000)	$ (4,865,000,000)	$ 1,022,000,000
Foreign [Member]
EffectiveTaxRateReconciliation [Line Items]
Net effect of different tax rates in non-U.S. jurisdictions	(2.40%)	(0.30%)	0.00%
Income (loss) from continuing operations before income taxes	$ (27,000,000)	$ (82,000,000)	$ 10,000,000