Basis of Presentation and Significant Accounting Policies - Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Other Tax Carryforward [Line Items]
Deferred tax assets, operating loss carryforwards	$ 1,197,188,000	$ 1,008,492,000
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%
Texas Margins Tax [Member]
Other Tax Carryforward [Line Items]
Deferred tax assets, operating loss carryforwards, tax effect	1,800,000	1,900,000
Internal Revenue Service (IRS) [Member]
Other Tax Carryforward [Line Items]
Operating loss carry forward periods	20 years
Operating loss carryforwards	3,100,000,000
State and Local Jurisdiction [Member]
Other Tax Carryforward [Line Items]
Operating loss carry forward periods	five to 20 years
Operating loss carryforwards	2,300,000,000
Net operating loss carryforwards, amount expiring in current year	$ 92,800,000