Mandatorily Redeemable Preferred Stock and Warrants (Details) (USD $)	3 Months Ended		9 Months Ended								3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 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	Dec. 31, 2009 Series C Mandatorily Redeemable Preferred Stock	Sep. 30, 2012 Series C-1 Mandatorily Redeemable Preferred Stock	Sep. 30, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Sep. 30, 2012 Series C-1 Mandatorily Redeemable Preferred Stock	Sep. 30, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Dec. 31, 2011 Series C-1 Mandatorily Redeemable Preferred Stock	Sep. 30, 2012 Series D Mandatorily Redeemable Junior Preferred Stock	Sep. 30, 2011 Series D Mandatorily Redeemable Junior Preferred Stock	Sep. 30, 2012 Series D Mandatorily Redeemable Junior Preferred Stock	Sep. 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											(754,000)		(754,000)		(927,000)	(21,790,000)		(21,790,000)		(22,049,000)
Accrued interest											12,757,000		12,757,000		8,909,000	6,780,000		6,780,000		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	60,488,000		60,488,000		53,210,000						45,498,000		45,498,000		41,477,000	14,990,000		14,990,000		11,733,000
Common stock, shares issued	19,703,479		19,703,479		19,289,489				750,000
Dividend rate (as a percent)													11.75%
Liquidation value											46,300,000		46,300,000			36,800,000		36,800,000
Interest expense related to mandatorily redeemable preferred stock	12,783,000	11,161,000	38,422,000	35,639,000							1,400,000	1,200,000	4,000,000	3,600,000		1,200,000	(200,000)	3,300,000	2,100,000
Accretion of discount											100,000	100,000	200,000	200,000		100,000	(1,000,000)	300,000	(500,000)
Dividend rate, if payment made in cash (as a percent)																10.50%		10.50%
Dividend rate, if amount accrued (as a percent)																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