Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2010
Income Taxes (Textual) [Abstract]
Income tax expense	$ 2	$ (3)
Valuation allowance			1,042
Approximate federal net operating loss carryforwards	1,899
Federal net operating loss carryforwards, expiration dates	2026 through 2032
Approximate federal alternative minimum tax credit carryforwards	49
Minimum taxable income needed to fully realize the U.S. federal net deferred tax assets	2,038
Foreign tax credit carryforwards	8
Foreign tax credit carryforwards, expiration date	expire in 2015
Approximate gross deferred tax assets operating loss and tax credit carry forwards that will expire in current year	1
Gross deferred tax assets related to state NOLs and tax credit carryforwards, expiration dates	2013 through 2032
Deferred tax assets operating loss tax carryforwards	266
Deferred tax assets, operating loss and tax credit carryforwards foreign	4
Valuation Allowance increased to	1,056
Increase in Valuation Allowance Impacted by current loss	13
Additional valuation allowance against deferred tax assets recorded	14
Increased in deferred tax assets valuation allowance	1
Percentage of change in ownership	50.00%
Period of change in ownership	3 years
Long-term tax-exempt rate	3.47%
Time period after the change in which amount of the limitation be increased or decreased by built-in gains or losses	5 years
Approximate annual NOL utilization had an ownership change occurred	63
Effective income tax rate	(8.00%)
Noncash income tax benefit on the loss from continuing operations		$ 3