Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2012
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 2,600,000,000
Potential reduction in future cash tax liabilities	991,400,000
Operating Loss Carryforward Limitations on Use Ownership Change Amount	50.00%
Operating Loss Carryforward Limitations on Use Ownership Change Significant Stockholder Ownership Percentage	5.00%
Operating Loss Carryforward Limitations on Use Ownership Change Ownership Threshold for Change in Control	4.99%
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards Expiration Periods	20
Operating Loss Carryforwards, Expiration Dates	2022
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards Expiration Periods	from five to 20 years
Operating Loss Carryforwards, Expiration Dates	2012
Operating Loss Carryforwards, Amount Expiring in Current Year	37,200,000
Texas Margins Tax [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Tax Effect	$ 1,900,000