Mandatorily Redeemable Preferred Stock and Warrants (Details) (USD $)	3 Months Ended		6 Months Ended									3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jul. 28, 2008 2008 Warrants	Dec. 14, 2010 2010 Warrants	Jul. 28, 2008 Series B-2 Preferred Stock	Dec. 31, 2009 Common stock	Jun. 30, 2012 Series C Mandatorily Redeemable Preferred Stock	Dec. 31, 2009 Series C Mandatorily Redeemable Preferred Stock	Jun. 30, 2012 Series C-1 Mandatorily Redeemable Preferred Stock	Jun. 30, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Jun. 30, 2012 Series C-1 Mandatorily Redeemable Preferred Stock	Jun. 30, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Dec. 31, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Jun. 30, 2012 Series D Mandatorily Redeemable Junior Preferred Stock	Jun. 30, 2011 Series D Mandatorily Redeemable Junior Preferred Stock	Jun. 30, 2012 Series D Mandatorily Redeemable Junior Preferred Stock	Jun. 30, 2011 Series D Mandatorily Redeemable Junior Preferred Stock	Dec. 31, 2011 Series D Mandatorily Redeemable Junior Preferred Stock	Dec. 14, 2010 Series D Mandatorily Redeemable Junior Preferred Stock
Mandatorily Redeemable Preferred Stock
Issued (in shares)								120,000			133,982	133,982		133,982		133,982	120,000		120,000		120,000	120,000
Issued												$ 33,495,000		$ 33,495,000		$ 33,495,000	$ 30,000,000		$ 30,000,000		$ 30,000,000
Discount, net of accretion												(811,000)		(811,000)		(927,000)	(21,938,000)		(21,938,000)		(22,049,000)
Accrued interest												11,437,000		11,437,000		8,909,000	5,752,000		5,752,000		3,782,000
Mandatorily Redeemable Preferred, net (in shares)												133,982		133,982		133,982	120,000		120,000		120,000
Mandatorily Redeemable Preferred, net	57,935,000		57,935,000		53,210,000							44,121,000		44,121,000		41,477,000	13,814,000		13,814,000		11,733,000
Common stock, shares issued	19,708,494		19,708,494		19,289,489				750,000
Dividend rate (as a percent)														11.75%
Liquidation value										44,900,000							35,800,000		35,800,000
Interest expense related to mandatorily redeemable preferred stock	12,858,000	13,120,000	25,639,000	24,478,000								1,300,000	1,300,000	2,600,000	2,400,000		1,100,000	1,200,000	2,100,000	2,300,000
Accretion of discount												100,000	100,000	100,000	100,000		100,000	300,000	100,000	500,000
Dividend rate, if payment made in cash (as a percent)																	10.50%	10.50%	10.50%	10.50%	10.50%
Dividend rate, if amount accrued (as a percent)																	11.50%	11.50%	11.50%	11.50%	11.50%
Value of preferred stock issued, net of unamortized discount																						8,300,000
Original discount on issuance of preferred stock																						$ 21,700,000
Number of shares that can be purchased on exercise of warrants issued in consideration for obligations under debt instrument						240,000	3,495,000
Exercise price (in dollars per share)						$ 9.05	$ 3.84