Income Taxes (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation Allowance [Abstract]
Change in valuation allowance		$ 76	$ 149	$ 179
Valuation allowance		1,125	1,042
Federal deferred tax assets		831
State deferred tax assets		290
Foreign deferred tax assets		4
Increase in Valuation Allowance Impacted by current loss		76
Increase in deferred tax assets valuation allowance		7
Net Increase in Valuation Allowance		83
Net deferred tax (liabilities) assets		13	10
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Approximate federal net operating loss carryforwards		2,051
Approximate federal alternative minimum tax credit carryforwards		49
Minimum taxable income needed to fully realize the U.S. federal net deferred tax assets		2,189
Foreign tax credit carryforwards		8
Foreign tax credit carryforwards, expiration date		Jan. 01, 2015
Deferred tax assets operating loss tax carryforwards		290
Approximate gross deferred tax assets operating loss and tax credit carry forwards that will expire in current year		1
Deferred tax assets, operating loss and tax credit carryforwards foreign		1	4
Percentage of change in ownership		50.00%
Period of change in ownership		3 years
Long-term tax-exempt rate		2.87%
Time period after the change in which amount of the limitation be increased or decreased by built-in gains or losses		5 years
Net Operating Loss Limitations on Use		86.9
Income Tax Penalties and Interest [Abstract]
Total amounts of interest expense recognized on consolidated balance sheet		2
Unrecognized Tax Benefits, Income Tax Penalties Accrued		1
Total amounts of interest and penalties recognized in consolidated statements of operations		1	(1)	0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		7	8	16
Estimated lower range for change in gross unrecognized tax benefit		0
Estimated upper range for change in gross unrecognized tax benefit		4
Income Taxes (Textual) [Abstract]
Income tax benefit from continuing operation	19			18
Undistributed earnings		637
Estimate of the amount of deferred tax liability		$ 26
Maximum [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Federal net operating loss carryforwards, expiration dates		2032
Gross deferred tax assets related to state NOLs and tax credit carryforwards, expiration dates		2032
Income Tax Penalties and Interest [Abstract]
Period of Limitations in Foreign and Us Jurisdictions		5 years
Minimum [Member]
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Federal net operating loss carryforwards, expiration dates		2026
Gross deferred tax assets related to state NOLs and tax credit carryforwards, expiration dates		2014
Income Tax Penalties and Interest [Abstract]
Period of Limitations in Foreign and Us Jurisdictions		3 years