Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Operating Loss Carryforwards [Line Items]
Income Tax Expense (Benefit)	$ (288,842,000)	$ 0	$ (288,842,000)	$ 0
Deferred tax asset, net	285,141,000		285,141,000		0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	32,044,000	7,555,000	45,335,000	12,972,000
Tax preservation rights plan, per investor maximum acquisition percentage of common stock outstanding						4.95%
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Expense (Benefit)	288,842,000
Deferred tax asset, net	285,100,000		285,100,000
Reserved net deferred tax asset					327,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards	$ 283,200,000		$ 283,200,000		$ 285,000,000