Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Operating Loss Carryforwards [Line Items]
Income Tax Expense (Benefit)	$ 0	$ 0	$ (288,842,000)	$ 0
Deferred tax asset, net	280,373,000		280,373,000		0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	30,598,000	11,328,000	75,933,000	24,300,000
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]
Reserved net deferred tax asset					327,000,000
Deferred Tax Assets, Operating Loss and Tax Credit Carryforwards	$ 273,000,000		$ 273,000,000		$ 285,000,000