Income Taxes (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Mar. 31, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income Taxes (Textuals) [Abstract]
Income tax expense (benefit)	$ 1,000,000		$ 7,000,000		$ (2,000,000)	$ (10,000,000)
Effective tax rate	1.60%
Threshold period (in years) for cumulative losses	4 years
Approximate federal net operating loss carryforwards	1,700,000,000				1,700,000,000
Federal net operating loss carryforwards, expiration dates					2026-2031
Approximate federal alternative minimum tax credit carryforwards	52,000,000				52,000,000
Minimum taxable income needed to fully realize the U.S. federal net deferred tax assets	1,800,000,000				1,800,000,000
Foreign tax credit carryforwards	5,000,000				5,000,000
Foreign tax credit carryforwards, expiration date					2015
Approximate gross deferred tax assets related to state NOLs and tax credit carryforwards	282,000,000				282,000,000
Approximately gross deferred tax assets operating loss and tax credit carry forwards that will expire in current year	11,000,000				11,000,000
Gross deferred tax assets related to state NOLs and tax credit carryforwards, expiration dates					2012-2031
Approximate gross deferred tax assets related to foreign NOLs	5,000,000				5,000,000
Net increase in valuation allowance					96,000,000
Valuation allowance against deferred tax assets	980,000,000				980,000,000		884,000,000
Additional valuation allowance against deferred tax assets recorded	26,000,000	54,000,000
Increased in valuation allowance impacted by other discrete adjustments					80,000,000
Increased in deferred tax assets valuation allowance	16,000,000				16,000,000
Ownership changes that imposes limitations on a corporation's ability to utilize NOLs					50 percentage points over a three-year period
Long-term tax-exempt rate	4.17%				4.17%
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	62,000,000				62,000,000
Interest expense related to unrecognized tax benefits	4,000,000				4,000,000
Penalties related to unrecognized tax benefits	0		1,000,000		0	1,000,000
Recognized tax benefit due to reversal of reserves for uncertain resolved tax positions		6,000,000
Noncash income tax benefit	3,000,000			19,000,000	(3,000,000)	(19,000,000)
Number of months examinations maybe be resolved	12 months				12 months
Estimated lower range for change in gross unrecognized tax benefit	5,000,000				5,000,000
Estimated upper range for change in gross unrecognized tax benefit	$ 10,000,000				$ 10,000,000
Maximum [Member]
Additional Income Tax (Textuals) [Abstract]
Period of limitations in Foreign and U.S. jurisdictions					P5Y
Minimum [Member]
Additional Income Tax (Textuals) [Abstract]
Period of limitations in Foreign and U.S. jurisdictions					P3Y