Income Taxes - Operating Loss Carryforwards (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Change in deferred tax asset valuation allowance	$ (263,000,000)	$ (90,200,000)
Operating loss carryforward, losses When utilized impact additional paid in capital	32,000,000
Adjustments to additional paid-in-capital from net operating losses	12,100,000
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%
Net operating loss carryforward limitation on use, period for change in control	3 years
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]
Change in deferred tax asset valuation allowance	232,000,000	(84,300,000)
Operating loss carryforwards	3,100,000,000
Operating loss carryforwards, expiration date	2022
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Change in deferred tax asset valuation allowance	19,900,000	(5,900,000)
Operating loss carryforwards	2,300,000,000
Operating loss carryforwards, expiration date	2014
Net operating loss carryforwards, amount expiring in current year	92,800,000
Operating Loss Carryforwards, Amount Expired	69,800,000
Texas Margins Tax [Member]
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards, tax effect	$ 1,800,000	$ 1,900,000