Income Taxes (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income Taxes
Deferred tax valuation allowance	$ 5,400,000		$ 8,200,000	$ 11,503,000	$ 13,204,000
Balance of deferred tax valuation allowance	265,300,000			265,300,000		253,800,000
Federal operating losses carryforward (in years)				20
State operating losses carryforward, low end of the range (in years)				10
State operating losses carryforward, high end of the range (in years)				20
Effective income tax rate (as a percent)	0.00%		0.00%	7.40%	0.00%
Liability for Gross Unrealized Tax Benefits	1,300,000			1,300,000		3,200,000
Accrued Interest and Penalties	544,000			544,000		2,700,000
Decrease in Liability for Gross Unrecognized Tax Benefits				1,900,000
Settlement Payment for Income Tax		1,600,000
Tax Adjustments, Settlements, and Unusual Provisions				$ (2,400,000)